Zoo Volunteer

A Balkan invader

2012-06-04T10:10:00.001-07:00

At around the same time the marshes of Britain were echoing to the bellows of fighting aurochs, a bird that would be an astronomically mega tick for a birder was nesting in fens across southern Britain from the Somerset levels to what would one day be called Norfolk. Today the Dalmatian Pelican Pelecanus crispus is found no closer to the UK than the Balkans, but from the Neolithic almost to Roman times it was a regular part of the British avifauna. How and why it ceased to be a British bird is something of a mystery, but the ecological requirements of the species today offers some clues.

The Dalmatian pelican during the breeding season is usually found inland, where it nests in colonies up to 250 pairs strong on islands in lakes. The colonies have a limited life as the trampling by the huge birds destroys the vegetation, so an individual site today on average only lasts about 3 years. The clutch size is up to 4 eggs, and the chicks take up to 12 weeks to fledge. The young will take several years to reach maturity, but are long lived. The very similar Australian Pelican for example can live to 25 years old, possibly more.

The Dalmatian Pelican is the largest living pelican, and can weigh up to 15kg or more. As with most large predators, Dalmatian Pelicans eat whatever is easiest to catch – mostly carp, roach, or pike in the breeding season. In the winter, when it disperses towards the coast or migrates longer distances, it feeds on sea fish, eels, or smaller prey like shrimps. It is a social bird, and will feed collectively to herd shoals of fish together.

How soon after the end of the last Ice Age the Dalmatian Pelican arrived in Britain is unclear, but at the height of the last glaciation it would undoubtedly have been confined to the Eastern Mediterranean. As the climate warmed, it could have spread up the Danube and then down the Rhine to arrive in northwest Europe and Britain. Around 6200 BC the Atlantic climate period began. From then until 3500 BC the British climate was the warmest since the end of the last glaciation, and it was during this period that farming arrived in Britain. The first farmers had followed much the same route as the pelicans, but humans had already been long resident in Britain by then. These Mesolithic peoples had lived off wild plants, hunting, and fishing, but were not necessarily nomadic as is sometimes portrayed – fishermen tend to stick close to their harbours.

If pelicans were already nesting in Britain by the Mesolithic it is unlikely that the human population would have had a significant impact – they certainly did not prevent the initial colonisation and in any event the population was too low to be of significance. Farming allowed much greater numbers of people to inhabit the area, and they would have had much more impact on the birds, not so much by direct hunting than by fire setting in marshes to improve grazing, and disturbance of the breeding colonies by their livestock.

The loss of pelicans from Britain was probably due as much to climate change as to people. Towards the end of the Iron Age in southern Britain from around 650 BC the climate became noticeably cooler and wetter. This would have seriously impacted nesting success and was probably the cause of the pelican’s extinction as a nesting bird, although as late as Roman times it was apparently still present in northwest Europe. The Romans carried out extensive drainage of fenlands for farming in Britain and elsewhere in northern Europe, further reducing the habitat and potential sources of recolonists as the weather warmed again during Roman times.

Today, the Dalmatian pelican is classed as Vulnerable. The population centred on the Balkans has around 5,000 adults, while the central Asian population centred on Kazakhstan has around 6-9,000. Major threats are habitat disturbance, organochlorine pesticides, persecution by fishermen, and some hunting, especially in Mongolia, where the bill is supposed to have special properties in the care of horses. The Balkan population is reasonably secure, and in fact has increased slightly, but the Mongolian population is on the verge of extinction. The chances of a reintroduction project in the UK are non existent unfortunately, as the absence of the bird from western Europe suggests that conditions are no longer suitable for it. Unfortunately, pelicans as a group do not have a good breeding record in zoos, and the giant Dalmatian Pelican would probably be harder than most to breed, as it would require several pairs and a very large lake to encourage nesting, a luxury most zoos do not have. There are some in UK collections – I believe Paignton has them – but I have not found any records of them being bred.

(image from wikipedia)

The rise and fall (and resurrection?) of the Aurochs

2012-05-25T02:36:00.001-07:00

Skeleton of an Aurochs

With the extinction of the mammoth and straight-tusked elephants of Europe only two really large bodied herbivores remained, the Wisent or European Bison (Bison bonasus) and the Aurochs Bos primigenius. Although Wisent reached the coast of France just as the climate warmed, they apparently never occurred in Britain in post-glacial times and the few thousand individuals surviving today have a distinctly southern and eastern distribution. For most of Europe the role of top herbivore was played by the Aurochs.

Aurochs were massive animals, with large bulls standing 1.8m or more at the shoulder and possibly reaching 1 tonne in weight. Accounts of the last surviving pure Aurochs from 16th century Poland describe an animal that was more placid than one might expect, but could be agile, fast, and very dangerous if annoyed. They seem to have preferred wetland habitats, probably because of the lusher grazing their large bodies required, and in fact one old name translates as ‘marsh walker’.

Although Aurochs were hunted by Mesolithic peoples, the numbers taken would not have threatened the species survival in the UK, as people were thin on the ground – estimates for the total worldwide population of humanity range from 5 to 20 million across the whole planet, so the number in the British isles were probably no more than 10,000 at any one time, probably much less. In any event, Red and Roe Deer were probably more favoured prey as they were easier (and safer) to catch.

Bull on left, cow on right

However, around 5000 BC things changed. The first Neolithic farmers arrived, probably in the South East, and began clearing the forest where the Aurochs took shelter, especially in the winter. More importantly, they brought with them their own cattle. These were basically domesticated Aurochs, but their ancestors were the Middle eastern sub species – some recent genetic studies indicate they were domesticated in Iran around the time agriculture was invented. These domestic cattle competed with the wild cattle for food and were protected from Wolves and Bears (the only predators aside from people Aurochs had to worry about) and the species went into a terminal decline. The same story was repeated on mainland Europe, and the last Aurochs died in Poland in the 16th century.

There the story would have rested, until in the early 20th century a pair of German zoo directors called Heinz and Lutz heck conceived a plan to resurrect the Aurochs. From descriptions of the last survivors, they attempted to use selective breeding from various primitive breeds to create a Mark II Aurochs that combined these traits, which they believed derived from interbreeding between domestic cattle and Aurochs before the Aurochs died out. They did in fact succeed in producing an animal which at least looked a bit like an Aurochs, and the breed survives to this day. There is however a sting in this tale. The Heck brothers were enthusiastic Nazis, and Lutz took part in the demolition of Warsaw Zoo (many animals were stolen and taken back to Germany). In addition, it is pretty generally agreed that the results of their efforts are different in many respects from the true Aurochs (they are smaller and much more heavily built for one thing), so although Heck cattle are sometimes used as grazing animals in habitat restoration projects, they are basically a rather embarrassing historical relic.

Heck bull

Another, more interesting historical relic however exists in England at Chillingham Castle in Northumberland. The castle has a very large park which has been enclosed since the 13th century, and in the grounds live a herd of wild cattle. They have a very distinctive appearance – pure white with red ears – and live a completely wild existence. Their origins are obscure, but they may be descended from special sacrificial animals from pre-Roman times, or simply feral Medieval cattle. Either way, their behaviour may give some insight into how wild Aurochs behaved.

Some of the Chillingham herd

Bulls are solitary, and fight viciously (often to the death) with other bulls. Females too can be aggressive with each other, and although they live longer than bulls the typical lifespan is around 15 years. For the first few days after calving the calf is hidden away in cover, with the mother returning twice a day to feed it. Once the calf is strong enough it follows its mother back to the herd. Although they are tough animals, hard winters can cause heavy mortality, and in 1947 there were only 13. Today there are around 100, with another 20 at another site. Calves are born all year round, but in recent years there have been more in winter, probably a result of warmer springs enabling cows to come into breeding condition earlier.

The case of the Chillingham cattle is a good example of the issues that can arise with what is now called ‘rewilding’ – the restoration of habitats by reintroducing various large mammals, both herbivores and carnivores. Is it actually necessary to recreate a look-alike of an extinct wild relative of a domestic animal, when its domesticated descendants will have exactly the same ecological affect? Does re-wilding have anything to do with actual conservation, or is it rather an aesthetic choice by urban man? Also, if this re-wilded landscape is a human creation, is it actually wild?

So what do you think?
Next week, I will be at the Bath and West Show – see you there!

(images from wikipedia)

The changing ecology of Britain - Part 1

2012-05-19T12:18:00.000-07:00

Hand axe from Boxgrove

Since the end of the last glaciation around 10,000 years ago, the environment of Britain has been transformed repeatedly by both natural and man-made alterations. New species have colonised, thrived, and become extinct, sometimes repeatedly, as alterations in climate, especially summer temperatures and rainfall, have made the British Isles suitable for one species and less so for others. Human predation has removed some species, especially large carnivores, but farming and forestry has also created new kinds of habitats which some species have exploited with great success. This series will cover some of those changes, and both the losers and the gainers in the changing face of Britain.

The first humans to live in the British Isles go back a very long way. Boxgrove man dates to around half a million years ago, and has been classed as Homo heidelbergensis. This ancient hominid was probably the ancestor of both the Neanderthals and anatomically modern humans, and from sites on the continent is known to have used fire to make hardened tips to their wooden spears. Although the brain size was on average less than modern humans, it overlapped with the lower end of the modern human range. Even then however, the human presence was already ancient – in 2010 flint tools dated at 800,000 years old were found in Norfolk.

Skull and model of straight-tusked elephant

At the time of Boxgrove, the British climate was warm, and animals were a strange mixture of animals we now think of as typically European, such as horse, red deer and wolf, and more southerly animals such as rhinos, lions, and elephants. How the humans interacted with them or affected their environment is not clear, but humans were already skilled hunters by this point and may have had significant impacts on the populations of favoured prey.

reconstruction of Neanderthals

The more famous Neanderthals were the next major species to occur in Britain. Britain during the glaciations was always a pretty inhospitable place however, and the number of Neanderthals at any one time in Britain was probably always low, even during warm interglacials. The last glaciation was particularly savage, and it was probably this, rather than direct competition with modern humans, which was the cause of their extinction. Although describing Neanderthals as extinct is itself something of a matter of semantics – it is now known that all human populations outside Africa carry some Neanderthal genes as a result of interbreeding in the Middle East with anatomically modern humans from Africa, so in a sense they are still with us – in fact they are us. All the Neanderthal DNA appears to have originated from male Neanderthal x female modern human offspring, as no mitochondrial DNA (passed down through the female line) of Neanderthal origins has been detected. This makes me wonder if the conventional portrayal of Neanderthals as being regarded as inferior beings by the modern humans they encountered is more a result of early 20th century racial theorising than anything that went on at the time – maybe modern humans regarded a Neanderthal son-in-law as a “catch”!

Whatever went on between the two forms of human, at almost the same time as the last Neanderthals were leaving the stage in Spain around 30,000 years ago, the first modern humans known from Britain were already living in Wales. These first pioneers however probably did not survive the peak of the Last Glacial Maximum around 20,000 years ago, and modern human settlement began with people who survived in Spain and southern France and then migrated north as the climate warmed.

At its peak, the ice front in Britain extended as far south as Gloucester, only a few miles north of Bristol, and most of the area from Bristol down far to the south would have been tundra, populated by Reindeer, Horse, Mammoth, and the associated carnivores – Wolf and Polar Bear in particular.

no prizes for guessing what this is

Britain and Ireland would have formed a single landmass as a result of the lower sea level, but where the English Channel now is would have been an icy Arctic river, choked with icebergs, and forming an important barrier to movement for mammals and amphibians. Mammoths survived in North West Europe until around 14,000 years ago, but the warming climate encouraged the conversion of grassland to forest, eliminating their habitat.

Reindeer/Caribou

The same environmental changes probably caused the extinction of other cold-adapted animals in Britain.. In much later Medieval sagas, Vikings living in Orkney are described as hunting Reindeer in Caithness, but even if the story is true they were long gone by the 1950’s when a small group were introduced to the Cairngorms. Today there are around 150 in the mountains, and the population is controlled to avoid overgrazing. For more on the Cairngorm Reindeer, visit here: http://www.cairngormreindeer.co.uk/index.html

The birds of course were just as affected. Some, like Ptarmigan and Snow Bunting, survived by retreating to mountain tops, but others relocated further North, visiting Britain only as wintering birds and breeding further north. In cold periods however some would spread further south again, and even today Snowy Owls winter in some years in the UK. Between 1967 and 1975, one pair even bred in Shetland.

Snowy owl

Next week, the post-glacial warming, and some unexpected birds.
(images from wkipedia)

News you may have missed

2012-05-12T01:47:00.001-07:00

As a break from series focussing on the animals on display, here are some news items that probably did not make the front page of your paper. For the full stories and more, check out the conservation links on the right.

Mauritius Wildlife Foundation:

Rodrigues Fruit Bat

MWF has saved most of the surviving bird species of Mauritius, home of the dodo, and is now working on environmental restoration of the pre-discovery habitats on Mauritius and the related island of Rodrigues. For more news check out their website.

• A count in February this year shows the current wild population of Rodrigues Fruit bats to still be over 10,000 individuals, despite two cyclones in the previous few months.

• MWF was admitted to the IUCN in November 2011

• MWF scientific director Professor Carl Jones is a finalist for the 2012 Indianapolis Prize for outstanding achievements in conservation – see here: http://www.indianapolisprize.org/

White-Tailed Tropicbird

• An ongoing project to reintroduce seabirds to Isle Aux Aigrettes in 2011 is ongoing. Seabird chicks are taken from Round island a few weeks before fledging and hand reared until they emerge from their nest burrows and have their first sight of the sea. Species involved are White-tailed Tropicbirds Phaethon leucurus, Red-Tailed Tropicbirds Phaethon rubricauda, and Wedge-Tailed Shearwaters Puffinus pacificus. It will be few years before these birds return to breed as adults.

Nature Iraq

Basra Reed Warbler

For obvious reasons conservation in Iraq has not been a high priority for many years, so the work done by the dedicated people at Nature Iraq is inspiring. Some recent news items include:
• The 10th Birdlife Middle East Partnership meeting is being held in Sulamaniya from 11th-14th May with participants from all over the Middle East. The conference will discuss bird protection in the region.

• A Reptile and Amphibian Advisory Team has been set up to survey the herpetofauna of the country (the last study was in 1959) and advise on conservation issues affecting reptiles and amphibians, including the Critically Endangered Kurdistan Newt Neurergus microspilotus.

Kurdistan Newt

• Nature Iraq has added its voice to the petition to UNESCO over the highly controversial Ilisu dam in Turkey, which will seriously affect both archaeological sites and the remaining wetlands in southern Iraq

• Thanks to a £300,000 Grant from Defra’s Darwin Initiative, a major new three year conservation programme is starting in Iraq. Focusing on the mountainous region of Kurdistan the project will involve experts from the Royal Botanic Garden Edinburgh (RBGE) and BirdLife International (BirdLife), in partnership with Iraqi NGO Nature Iraq (NI). The project will generate new data for conservation and resources for protected area management and environmental education. The team’s aim is to make serious progress in addressing the challenges of conservation resulting from nearly 30 years of scientific isolation

And finally at Bristol:

Bristol has successfully bred the Antilles Pink-Toe Tarantula Avicularia versicolor. The babies have now been separated into individual vials for growing on and can be seen in Bug World.

Adult Antilles Pink Toe

Baby Antilles Pink Toe

Our baby gorilla Kukena, born September last year, is now starting to take his first steps.

Salome and Kukena

images from Arkive, Wikipedia, Bristol Zoo website)

Turtles 8: It swam with Dinosaurs

2012-05-05T01:51:00.005-07:00

Young C.inscuplta

The last of Bristol Zoo’s chelonians (for now) is perhaps the strangest freshwater turtle in the world, the Fly River or Pig-nosed Turtle, Carettochelys insculpta. Now known only from Papua New Guinea and parts of northern Australia, it is the last survivor of an ancient turtle lineage related to the more familiar soft-shell turtles Trionyx, and which was once found all over the world. The family dates back to the early Cretaceous, but became progressively restricted in distribution after the end of the age of dinosaurs and it has probably been restricted to its current range since the start of the Pliocene.

Carettochelys is perhaps the most highly aquatic of all freshwater turtles, and has its limbs modified into flippers similar to those seen in marine turtles. Males spend their entire lives in the water, and females only emerge to lay eggs on sand banks at the start of the dry season. Although they spend the majority of their time in fresh water, they have been known to enter brackish water or fully marine environments in search of food. As with many turtles, Carettochelys is mainly herbivorous, feeding ona variety of aquatic plants, plus fruit and foliage that falls into the water. It will also feed on carrion however, and will also catch larger aquatic invertebrates. It needs a lot of food, as it can grow to a considerable size (over 60cm has been recorded), although females mature at around 30cm. To obtain this, they range over large areas, with a single individual being recorded has having a home range of 10km of river.

C.insculpta in habitat

Females seem to produce eggs every other year, probably using the non-breeding years to build up resources. They usually lay 2 clutches in breeding years, with a typical clutch size of 10-12 eggs. Eggs are laid in sandy beaches, usually used by most of the females in the area, at the start of the dry season, and the fully formed unhatched young wait in a state of aestivation in their shells until rising water floods the nests, when they hatch explosively and quickly make their way into the water. Thee young feed mainly on Vallisneria, a familiar aquarium plant, and take many years to reach maturity – 16 years or so for females. With that long a developmental period, the lifespan is probably just as long as other turtles, probably at least 50 years.

Newly hatched C.insculpta

Carettochelys and its eggs have been eaten by people since earliest times, but today a major threat comes from feral water buffalo, which crush and trample eggs on the nesting beaches. These pressures, combined with natural enemies like crocodiles (which eat adults), and monitor lizards (which eat eggs), has placed the species in the Vulnerable category on the IUCN red list.

With its aquatic lifestyle, captive care of Carretochelys is somewhat different to other turtles. At Bristol we have three which live in one of the large tanks in the Aquarium, which they share with various large Asian fish. At present ours are only around 20cm shell length, so they have some time before they are large enough to breed. At that size, we will have to take steps to provide them with a nesting beach, assuming we have a pair (males and females are identical when young). For an account of how are animals were bred at Rotterdam zoo, see the link below.

(Images from Wikipedia, Arkive)

Further reading: The Ecology and sex determination of the Pig-Nosed Turtle, Carettochelys insculpta, in the wet-dry tropics of Australia.J.Sean Doody http://www.canberra.edu.au/centres/iae/pdfs/2002_Doody_PhD_thesis.pdf

Breeding Caretochelys at Rotterdam Zoo: http://www.scribd.com/doc/59957555/Reproduction-of-the-Pig-nosed-Turtle

Turtles and Tortoises 7: the (no longer) Egyptian Tortoise

2012-04-28T01:28:00.001-07:00

Baby T.kleinemanni

For many years Bristol has had on show one of the world’s smallest tortoises, the Egyptian or Kleineman’s Tortoise Testudo kleinemanni. Despite its’ name, sadly it is no longer found in Egypt itself, and is classed as Critically Endangered in the wild.

Threats to tortoises I have described in previous posts have mainly been from habitat destruction and collection for food. With T.kleinemanni the situation is different, as practically the entire cause of its current dire situation is collection for the pet trade.

In the past, a trade in wild caught tortoises, usually larger species such as Spur-thighed T.hermanni or Greek T.graeca was widespread in Europe. These were usually collected from Spain, Italy, or Greece, and sold very cheaply in pet shops. Of course, in a British climate attempting to keep such creatures in the back garden without any of the equipment or lighting available today, was a recipe for disaster, and most died within a year or two. As European populations declined, the trade moved to new areas, and among the species targeted was T.kleinemanni. As a desert edge specialist, these had an even poorer life expectancy in Europe then Mediterranean species, but the cost of collection was low, there were few laws governing the trade, especially in the source countries, and as a result the species became extinct in Egypt. Today the sole remaining effective population, with perhaps 5,000 adults, is to be found in Libya, and that is also very vulnerable. They are traded inside Libya itself, even though they are protected under CITES, and the recent upheavals can have done nothing for law enforcement of what environmental protection laws Libya currently has.

Confiscated T.kleinemanni, Genoa, 2005

In the past T.kleinemanni probably had a range throughout the edge of the Sahara, living near wadis and oases,with the larger T.graeca and T.hermanni in the more vegetated regions. Aside from its size its lifestyle is probably the same as for its larger relatives, with the exception that the seasonal threat comes from summer heat rather than cold winters, and as a result it will aestivate in the hot months. The true T.kleinemanni is found only west of the Nile delta, populations to the east have been split as T.werneri, with a range through the Arabian Peninsula into the Negev.

kleinemanni on left, werneri on right

Despite its small size (even a large female is only the size of a coffee mug) T.kleinemanni probably has much the same life expectancy as its larger relatives. In the wild lack of availability of food means they probably do not grow large enough to breed until they are over 10, perhaps even 20, years old, although in captivity they can be mature by five or so. Mating occurs in the spring, and a small clutch of 1-5 eggs is laid in a nest dug in the ground. When the young hatch they are about 2cm long, and soon start feeding on grasses and herbs in the dry scrub which is their natural habitat.

T.kleinemanni habitat

One interesting feature of T.kleinemanni is their known range. As far as is known they do not occur west of Libya or far from the coast, but in wetter periods of earth’s history North Africa was much greener and suitable habitat would have extended over a much wider area. It is possible that relict populations may exist further south and west than are now known, but the areas are little studied and no one knows for sure.

The animals we currently have on show are part of a group confiscated from animal smugglers. Descendants of wild caught animals are in the pet trade, but unfortunately at that time it was not realised that the western and eastern populations were different species, and it is probable that the two forms were hybridised. Our animals are not yet old enough to breed, but we have hopes they will do so in the future.

For more information on this lovely species, see the tortoisetrust website at http://www.tortoisetrust.org/guests/tortoisecare/species.html

(images from Bristol Zoo, wikipedia, tortoisetrust.org)

Turtles and Tortoises 6: Giant Pond Turtle

2012-04-20T10:57:00.005-07:00

Orlitia borneensis

A new addition to Bristol Zoos’ collection of turtles this year is a pair of one of the largest freshwater turtles in the world, the Giant Pond Terrapin Orlitia borneensis. With a shell length of 80cm and a maximum weight of 50kg (or as much as Cheryl Cole as the sign somewhat ungallantly puts it) this species is an impressive sight. As you might guess from the specific name, it is found in Borneo, but its range extends through Sumatra and through peninsula Malaya as well.

Throughout its range Orlitia appears to be a thinly distributed species, and although it has been little studied in the wild it appears to be rather aggressive to its own kind – or pair are currently separated because of the males’ aggression. They do not appear to bask much, and seem to spend a lot of time patrolling the mud at the bottom of still or slow moving waters. In this behaviour they somewhat resemble the Black Marsh Turtle Siebenrockiella that I described last week, which is interesting as they are believed to be each others closest living relatives.

Rare animals that live at the bottom of muddy waters are not exactly easy to study, and the ecology of the wild animal is little known. They appear to be omnivorous in captivity, happily feeding on fruit and other plant material, but they also eat snails, fish, and other aquatic life. They will also scavenge, which is how they get caught on hook and line and wind up in Asian food markets. In common with all the other Asian turtles, as a result they are Endangered throughout their range.

Orlitia for sale in an Asian market

I have only been able to find one account of breeding Orlitia, a clutch of four eggs at a rescue centre which produced a single youngster. Geoemydid turtles appear to produce small clutches for the most part, but may produce multiple clutches in a season, and it is probable that Orlitia does the same.Apparently they have been bred in warm climates in outside ponds, but I have not been able to find an account of them breeding in the UK. Hopefully Bristol will be a first for this species, but it may take a while to get the conditions right.

(images from Wikipedia, World Chelonia Trust)

Turtles and Tortoises 5: Black Marsh Turtle

2012-04-13T01:21:00.000-07:00

The aquatic chelonians I have been discussing so far all belong to a single family, the Geoemydidae. This is the most diverse of all living groups of turtles, with over 70 different species in 23 genera. The centre of distribution of the family is in south east Asia, with outliers in Europe and North Africa (the European Mauremys species), and a separate group in Central and South America (the Neotropical Wood Turtles Rhinoclemmys). Almost all of them are highly aquatic, and even the more terrestrial forms tend to prefer damp habitats. Despite this, they are generally believed to be close to the fully terrestrial tortoises such as the Aldabra Giant Tortoise and its smaller relatives. The age of the group is not clear, but it probably dates back to the late Cretaceous.

Part of this diversity of aquatic turtles is the species I will right about today, the Black Marsh Turtle Siebenrockiella crassirostris. They are sometimes calling smiling terrapins, as the jaws have an upward curve.As one would expect from their body shape, which is fairly streamlined for a turtle, they are highly aquatic, although they will sometimes emerge to bask. Compared to their relatives, they are more carnivorous, feeding heavily on aquatic insects, snails, and fish. As an animal fairly high up the food chain, they tend to accumulate toxins, and in some areas they have been shown to carry high levels of mercury in their tissues. They prefer shallow water, and spend most of their time prowling over the mud at the bottom, or burying themselves in it.

Black Marsh Turtles have featured heavily in Buddhism, and are often kept in ponds in the grounds of temples, where they are believed to contain the souls of people who died saving others from drowning. One would think that with these connections the species would be in good shape, but unfortunately they share the fate of other Asian turtles in being exported for food and Chinese medicine in vast numbers (135,000 from Malaysia alone in 1999). As a result, it is classed as Endangered in Vietnam and Cambodia, and Vulnerable in the rest of its range, which extends south from Vietnam to Malaysia and the eastern islands of Indonesia.

In common with many of their relatives, they lay small clutches of eggs, one or two usually, but females can produce 3 or 4 clutches in a single breeding season. Unlike almost all other turtles, they have a chromosomal system of sex determination, with males being XY and females XX. In the majority of other turtles the gender of the hatchling is determined by temperature, usually with temperatures below 30 degrees or so producing females and higher temperatures producing males. How widespread this chromosomal system is found is not much studied at present, but I am inclined to wonder if it is an adaptation to very constant environmental temperatures and small egg clutches, which would mean that there was not enough temperature variation within a nest to generate male and female offspring from the same clutch. If so, other turtles with a similar lifestyle may be found to show similar sex determination patterns.

Not all the animals exported for food markets wind up being eaten. In 2001 a customs confiscation in Hong Kong resulted in the founder stock for our Black Marsh Turtles arriving at Bristol. Despite extensive quarantine and veterinary care, the stress and mistreatment they had experienced before arriving resulted in half the rescued animals dying within a year. Despite these setbacks, in 2004 the first baby Black Marsh Turtle to be born in a European zoo hatched at Bristol in 2004. Even so, they are rarely seen in zoos, probably because they are not as colourful or conspicuous as some other species, and the total zoo population in Europe is probably under 50 animals.

Next week, the largest of the Asian Turtles, the Giant Pond Turtle

(images from wikipedia)

Turtles and Tortoises 4: Annam Leaf Turtle

2012-04-06T02:24:00.000-07:00

M.annamensis adult

One of the peculiar features of the fauna and flora of Europe is that many of their closest relatives live in eastern Asia, with a vast gap in between with no connecting forms. This is a signal of the geological and climate events that have effected Eurasia, including the uplifting of the Himalaya following the collision of the Indian subcontinent with Asia, and above all the glaciations of the last few million years. In Europe the main mountain chains are aligned east-west, creating roadblocks to the migration of species north and south in response to climate change, whereas in eastern Asia mountain chains tend to be aligned north-south. As a result, while glaciations caused repeated extinctions in Europe, their Asian relatives managed to survive.

M.leprosa (Spain)

Among the various animals which display this distribution pattern are the leaf or pond turtles belonging to the genus Mauremys. Today there are six species, three with a distribution centred round the Mediterranean, and another three in Eastern Asia. Recent DNA work has shown that they are closely related to the Cuora I discussed in the last post, and the Asian genera Chinemys and Ocadia are part of the same group.

The rarest of the group is the species we have at Bristol, the Annam Leaf Turtle M.annamensis. The most southerly of the Asian species, it is found only in coastal lowlands in central Vietnam. Its closest relative is believed to be the Yellow Pond Turtle, M.mutica, which is found to the north in Vietnam and southern China.

range of M.annamensis

All the Mauremys species prefer slow-moving or still waters with heavy plant growth in which they can hide, with sloping banks that enables them to climb out of the water to bask in the sun, which is very important for their health. Not only does the sunlight enable them to thermoregulate, but drying out under a hot sun kills off the leeches and other parasites that swarm in their natural habitat. So eager are they to bask they will frequently climb on top of each other to get to the best spot.

Mauremys are adapted to warm temperate and sub-tropical climates, and the western species are often exposed to very cold weather for at least part of the year. In common with other aquatic turtles, they hibernate underwater, only coming up on warm days. In the more seasonal parts of their range, where the ponds may dry up in the summer, they will also aestivate buried in the mud for part of the year.

As with most aquatic chelonians, they are omnivorous, feeding on aquatic insects, snails, worms and occasional fish, but also taking plant material. Mating takes place in the water, with the gravid females seeking out soft earth ear the water to lay a clutch of 4-8 eggs. As with most of not all chelonians, they have temperature-dependent sex determination, with egg incubation temperatures affecting whether the hatchling is male or female. In most species, the key temperature is around 30oC, but the exact temperature for M.annamensis is as far as I am aware not yet determined with certainty. Knowledge of this is however very important for conservation, as by incubating eggs at the correct temperature it is possible to maximise the number of egg-producing females and so maximise productivity in the captive population.

Captive adult M.annamensis

The threats today for the Annam leaf Turtle are the same as for all the other Asian chelonians – over-collection for food and habitat destruction. Although various species of turtle are now being farmed in China, often these animals are hybrids and therefore valueless for conservation purposes, and also belong to a fairly restricted number of species. This is not a minor operation– a paper in Oryx Vol 42/1 in January 2008 estimated the number of captive farmed turtles of various species sold in China as 300 million animals per year. The trade in captive farmed freshwater chelonians is by no means confined to Asia either, for example between 2002 and 2005 the US declared exports of over 31 million turtles, a large proportion of which were to mainland China, Hong Kong, and Taiwan. As most of these were the well-known Red-Eared Slider Trachemys scripta, there is an additional problem of disease being spread around the world and escaped farm animals becoming established in the wild and competing with native species.

To return to our own animals – we currently have 6 juveniles bred at Chester Zoo on show. They are only a few years old, so it will be at least 3 or 4 years before they are large enough to produce offspring of their own. As M.annamensis is classed as Critically Endangered, this cannot happen soon enough.

(Images from European Freshwater Turtle Breeders Association, Wikipedia, Arkive)

References:

The freshwater turtle genus Mauremys D.Barth 2003 http://vipersgarden.at/PDF_files/PDF-648.pdf
Declared Turtle Trade from the US – World Chelonia Trust

http://www.chelonia.org/articles/us/USmarketintropage.htm

Turtles and Tortoises 3: Boxed into a corner

2012-03-31T02:08:00.000-07:00

C.amboinensis

One of the most serious conservation issues today is the catastrophic decline in recent years of the various species of turtle to be found in south-east Asia. Turtles have been used for local consumption for many years, but urbanisation (which destroys habitat), agricultural development, pollution, and above all over collection from the wild for the expanding food markets of China has placed all of them on the critical list. Many species are in fact only known from specimens found in food markets, and probably have very restricted ranges if they still survive at all.

Among these threatened species are the various Asian box turtles of the genus Cuora. As with their more well know American equivalents, the various box turtles placed in Terrapene, they have a flexible hinge on the plastron (the underside armour) which enables them to seal themselves completely inside their shell.. At present at least ten species have been described, many with several subspecies, and the range of the genus extends from India across Malaysia and north into Vietnam and southern China.

C.flavomarginata

Cuora favour damp habitats, and many species are semi-aquatic, and in past centuries many forms could be found around human habitations, as flooded rice fields were ideal for them. Although they live in areas with high humidity and temperatures, the more northerly and high altitude forms seem to be tolerant of low winter temperatures, although whether they go into true hibernation is unclear.

As with most semi-aquatic chelonians, Asian box turtles are omnivorous, but in most species the adults mostly rely on vegetation. They will happily consume snails, insect larvae, small fish or frogs if they get the chance however. They are not very prolific, laying only a few eggs each year, and as a result are extremely vulnerable to exploitation, especially as this mostly involves breeding size adults. The growth rate and lifespan are unknown, but it is likely they take at least 7 or 8 years to reach maturity and have a lifespan of decades.

C.galbinifrons

At Bristol we have five species of Cuora on show and have bred several of them. As part of our commitment to turtle conservation, one room of the reptile house is a dedicated turtle breeding room. This is climate-controlled and contains the large plastic tubs we use for housing the animals off-show. Each tub is designed to give a combined water and planted land area and houses a pair or trio of adults of the various species. Currently our collection comprises the following:

Cuora amboinensis SE Asian Box Turtle 1.2 (Vulnerable)

Cuora flavomarginata Yellow-margined box turtle 4.2.4 (Endangered)

Cuora galbinifrons Indochinese box turtle 3.3 (Critically Endangered)

Cuora mouhotii Keeled Box Turtle 2.1 (Endangered)

Cuora trifasciata Chinese Three-striped box turtle 0.0.2 (Critically Endangered)

C.trifaciata

We usually get a few eggs each year, but the breeding season is only just starting. I will update with any results later this year.

Finally, a plea to anyone who keeps these turtles themselves – it is absolutely vital that any adults of any of these species be in a breeding set up. If you have one on its own, even if it is a family pet for many years, please contact a turtle society (there is one in most countries) and see if you can match it up with a mate.

C.mouhotii

Next week, another rare turtle, this time from Vietnam.
(images from wikipedia)

Turtles and Tortoises 2: Not just on Galapagos

2012-03-24T11:54:00.000-07:00

Female D. dussimieri, Bristol

Today, when the phrase giant tortoise is heard, people immediately think of the giant tortoises of the Galapagos. That group of species however is just the largest surviving group of species in a world which once had giant tortoises almost everywhere, from South America to Southeast Asia. Away from the Galapagos, the largest tortoises alive today are the African Spurred Tortoise, Geochelone sulcata, a mainland species that can grow to 90cm long and a weight of 90kg, and the giant tortoises we have at Bristol, a group of seven Aldabra Giant Tortoises Dipsochelys dussumieri.

When human beings first colonised the islands of the Indian ocean, giant tortoises could be found almost everywhere. Species of Dipsochelys could be found on Madagascar, the Comores, and the Seychelles, and species of Cylindraspis lived on Mauritius, Reunion, Rodrigues and many of the smaller islands of the Mascarenes as well. As a result of human predation, fires, and introduced predators, especially pigs (which ate eggs), cats (which ate hatchlings) and rats (which ate everything) today the only place where giant tortoises dominate island ecosystems is the large atoll of Aldabra.

Male Galapgos tortoises displaying

Aldabra is around 34km long by 14km wide, with a central lagoon, and a total land area of 155km2. On this fairly small area live over 100,000 giant tortoises, which understandably dominate the entire ecosystem. Aldabra tortoises are grazers for the most part, and the result is a short ‘tortoise turf’ where any grasses grow on the islands. The climate of Aldabra is heavily influenced by the monsoon rains, and in the dry season the main cause of mortality is starvation and overheating in animals that cannot get to the central lagoon to wallow. They have a unique adaptation that enables them to suck up water through their nostrils from even the shallowest puddle, a very useful asset on an island with little standing fresh water.

It was thought at one time that tortoises grew so large on islands because of the lack of predators, but this is plainly not the case. Very large fossil tortoises are well known from many continental contexts, which had a full suite of predators, including mainland Europe and Africa. The reason that they are associated with islands today is simply because people are very fond of eating tortoises, and the large continental forms were mostly wiped out many thousands of years ago. Even where giant tortoises are found on islands, they did not necessarily evolve there – Aldabra has been completely submerged on several occasions and each time was re-colonised by giant tortoises from other islands when it re-emerged, probably from the Seychelles or Comoros islands.

Young G.sulcata. Note the spiky forelimbs

So why did they survive on Aldabra when their relatives on other islands were being eaten by hungry sailors? Probably the most significant cause is the lack of decent fresh water on the island – sailors preferred other islands with better supplies and the lack of water meant that pigs and cats had trouble surviving. It was a very close run thing however, and today a new threat has appeared in the form of climate change. Aldabra is only 8m above sea level at its highest point, and any rise in sea level could submerge most or all of the land, this time with no other source of giant tortoises to recolonise when it dropped again.

Tortoises are actually very good at dispersing across oceans, and the process still goes on. A few years ago an Aldabra tortoise washed up, still alive, on the coast of Tanzania, and judging by the barnacles on its shell it had been floating in the open ocean for several weeks. In the fluctuations of sea level during the last few million years, numerous islands have appeared above the waves and then disappeared again, and each time the land was probably covered in tortoises within a fairly short period. It would only take one gravid female surviving every thousand years or so to account for the recolonisation frequency that has been observed.

Today, Aldabra tortoises are key players in a major ecological experiment in Mauritius. Although the native Cylindraspis tortoises are extinct, the Mauritius Wildlife Foundation has been using them as ecosystem substitutes on Isle Aux Aigrettes, and now on Round Island, which are both close to Mauritius. There were actually two Cylindraspis species on Mauritius, one with a dome shaped shell and the other with a saddle back, and the Round Island experiment used both Aldabrans and Madagascar Radiated Tortoises, Astrochelys radiata, to see which would work best. The studies are in their early stages, but initial results are very encouraging, and Aldabrans have bred naturally or Isle Aux Aigrettes and will probably do so soon on Round island.

Given the history of what non-native animals can do to an ecosystem, the concept of using taxon substitutes for extinct fauna is understandably controversial. Management of reserves using domestic animals – for example grazing on nature reserves – is well established, but using wild animals for a similar purpose is potentially troublesome. Tortoises however are easy to control, can be readily removed if required, and perform many useful functions in an ecosystem. The most important is probably seed dispersal – many Mauritius plants produce their seeds at the base of the trunk at tortoise height, so they can be eaten and moved (slowly it is true) to another suitable growing spot. Tortoises also trample plants, and non-native plants often have much less resistance to such treatment than the native vegetation, which is also often less palatable than introduced weeds. However, tortoises can also disperse the seeds of non-native plants and invasive weeds, so the process needs to be carefully monitored.

For more on this topic, check out the MWF link on the list at the right and read their newsletters – well worth reading.

So what of the tortoises at Bristol? Our oldest two, a male and a female called Biggy and Twiggy, came to us in the early seventies from the university. Their exact age is unknown, but Biggy is probably at least 80 years old. Tortoises are famously long-lived, and one, a male called Adwaita, died in 2006 at the reputed age of 255. He alledgedly once belonged to Clive of India, and even if this is legend he had been at Alipore Zoological Gardens in Kolkata, India, since 1875. Our youngest tortoise, called Matilda, is only around 13 years old, and if she lives as long should see in the 22nd, possibly even the 23rd, century.

Adwaita, 2005

Although they live along time in captivity, giant tortoises, whether Galapagos or Aldabrans have as far as I know never bred in the UK. The problem appears to be the climate – breeding behaviour is triggered by the rains, and our climate does not provide the right triggers for breeding. Having said that, in some hot summer periods we have seen attempted mating by the two males we now have, so if we get the right kind of summer we may yet succeed in breeding them. Bristol has a good track record with breeding other species, so we live in hope.

Next week, another group of tortoises in trouble – the box tortoises of Asia.

(images from Bristol Zoo, wikipedia)

Turtles and Tortoises 1: The Pancake Tortoise

2012-03-17T02:33:00.000-07:00

This series of posts will be about one of the most famous groups of reptiles, the chelonians, variously referred to as turtles, tortoises or terrapins. Although they are subdivided into various taxonomic groups, these do not actually correlate with the various English names. In American English, they are almost all referred to as turtles. In British English, the names differ by habitat – tortoise is used to refer to terrestrial animals, turtle to marine forms, and terrapin to freshwater animals. Why we have so many names is unclear, as there are currently no breeding populations of any chelonian native to Britain. Any terrapins seen in the UK are invariably released pets, usually Trachemys scripta, the Red-eared Terrapin. In the past the European Pond Terrapin, Emys orbicularis, was resident in the UK but became extinct as a result of a change to a colder climate many thousands of years ago.

Among the animals I use for the talks to the public at our Amazing Animals talks is Oscar, a male Pancake Tortoise Malacochersus tornieri. People who are used to tortoises being more or less round, slow moving animals find him very surprising, as Pancake tortoises are as flat as their name suggests, and are fairly fast moving as well. Pancake tortoises originate from the more arid parts of Kenya and Tanzania, where they inhabit granite outcrops. They have their shape in order to fit more easily into the deep crevices where they spend most of their day, only emerging in the morning to feed on grasses and other plants.

As part of their adaptation for their steep habitat, they are extremely good climbers, with long, flexible legs ending in fairly long, strong nails. The soles of their feet are also covered with pointed scales, giving them additional grip as they clamber of rock surfaces. If they fall, their shape also makes it easier for them to right themselves and get back where they are going. Unlike most tortoises, their shell is flexible, which helps in their wedging themselves tightly into a crevice when threatened by a predator.

They are not very large animals, averaging around 17cm shell length as adults. The best crevices can usually accommodate several individuals, and they are often found in groups, usually with only a single adult male and a group of females. They are fairly secretive, as their flexible shells make them vulnerable when in the open. As with all animals, they have a variety of predators, with jackals, hyenas, and birds of prey being probably the most serious. Several different raptors feed on tortoises, and many have developed the same technique of getting through the armour plating – they carry the unfortunate tortoise high in the air, find a convenient boulder, and drop the tortoise onto it, killing the tortoise and breaking the shell. According to a (probably apocryphal) story, the Greek playwright Aeschylus was killed in this way by an eagle which mistook his bald head for a boulder.

Pancake tortoises are too small to lay large clutches of eggs, and instead lay a single egg at a time, but a female produces 4-6 eggs in a season. They can climb well to find suitable nest sites, and the incubation time for the egg varies considerably. This is probably an adaptation to ensure that all eggs hatch at the same time of year, when rains soften the soil and encourage plant growth, no matter when the egg was actually laid.

As dry country animals, Pancake tortoises are used to a very seasonal climate, and during the hottest and driest months of the year they may remain permanently in their crevices, avoiding the heat of the sun and conserving energy rather than trying to extract it from desiccated vegetation. The climate is never cold enough for them to go into hibernation. When the rains return, they emerge and feed on lush plants for the few months they are available, but their main diet is extremely high in fibre, low in nutrients. As a result they are even more than usually slow growing in the wild, and although the lifespan has not been definitively measured, is probably at least as long as more familiar species such as the Mediterranean Spur-Thighed tortoise, which can live to 150 years.

Unfortunately, as with many tortoises, they have been over-collected for the pet trade and are now classed as Vulnerable by the IUCN. They require a specialised vivarium in captivity, with a low humidity and a diet based around grasses and leafy plants, especially weeds and other high-fibre foods. They have been bred in captivity – in fact Bristol currently has three eggs in the incubator – but are not a prolific species.

One issue I point out when showing Oscar to the public is a shell deformity very common among captive bred tortoises. Called ‘lumpy shell’, it is a result of hatchlings and juveniles being fed a too high-protein diet when they are small. This results in the shell growing quicker than the rest of the tortoise, with a characteristic pyramiding effect. In the wild this could be a serious risk, at it means the affected individual cannot fit into a crevice as well, but in a captive environment is basically a cosmetic defect only.

While tortoise have been, and are, widely kept as pets both in the UK and elsewhere, even more than other animals they are a serious responsibility as a result of their long lifespans. Basically, if you have a pet tortoise, it needs to be in your will. If anyone is interested, please do your research first and remember that if Abraham Lincoln had been given a baby tortoise as a pet, there is a good chance it would still be grazing the White House lawn!

Next week – one of the worlds largest tortoises, the Aldabra Giant Tortoise.
(images from wikipedia)

New Arrivals: Brown-breasted Barbet

2012-03-10T00:55:00.000-08:00

Brown-breasted Barbet

If you walk past the Black-Cheeked lovebird aviary you will see they are now sharing it with a pair of very distinctive looking birds with red heads and very large bills. These are a pair of Brown-breasted Barbets, Lybius melanopterus. They are one of 43 species of barbets and tinkerbirds that span the African continent from south of the Sahara, where they live in a variety of habitats from thick jungle where they spend time in the canopy to the open scrub where some species prefer the ground. Likewise their diets are just as varied as their habitat; birds of the forests prefer fruits where some species in scrub areas may primarily consume termites and ants

.

The name barbet is applied to several similar- looking birds distributed throughout the tropics. They belong to the Piciformes, the order that includes the woodpeckers and their relatives, and like them they nest in holes, either in trees or excavated in the ground or termite hills, depending on species. Recent DNA analysis has shown they can be divided into several distinct groups:

1) The Asian barbets – these branched off first from the ancestral form, which was more similar to other birds.

Red-Crowned Barbet (Borneo)

2) The African barbets, including the Brown-breasted

3) The New world barbets and toucans. Presumably at a fairly early stage an ancestral African barbet managed to cross the Atlantic (which was much narrower then) and colonised South America, giving rise to these colourful and well-known birds

Gilded Barbet (Columbia)

Originating from a wide areas in eastern Africa, from Somalia south to Mozambique, Brown-breasted barbets are residents in woodland, especially lowland moist forest, although they also use arable areas, gardens, and plantations, so they are plainly quite adaptable. These mostly solitary birds eat a variety of fruits, including figs. They will also visit plantations and feed on cultivated fruit and vegetables. Fruit is eaten whole and indigestible material such as seed pits regurgitated later. They are believed to be important agents in seed dispersal.

In addition to fruit, they also eat a wide range of insects are taken, including ants, cicadas, dragonflies, crickets, locusts, beetles, moths, mantids, as well as scorpions and centipedes. On occasion, they may also feed on lizards, frogs and geckos.

Because the bill of the barbet is not as 'chisel-like' as a woodpecker they often dig their nesting holes into softer wood or plant materials; an African species digs into a dirt bank. They have been known to use old woodpecker holes also. Generally the holes are usually high above the ground. The hole is just large enough for a single bird to pass in and out of and is often placed under a branch to shelter from direct inclement weather. They typically nest in tree cavities. The hen usually lays between 2 to 4 eggs that are incubated for 13 - 15 days. Nesting duties are shared by both parents, but young from previous years may remain on the territory and help with raising the next generation of their siblings.

At present they are listed as Least Concern, but in common with many species, the long overdue EU import ban has revealed a lack of sustainability in the captive population. As a group, most of the worlds barbets are listed by the IUCN as of Least Concern, but one or two species with small ranges are listed as Vulnerable or Near Threatened. The most important function of the captive population is to act as model species to perfect breeding and husbandry protocols in case any more intensive intervention is needed for these threatened species.

Next week a new series: turtles, tortoises, and terrapins – past, present, and future.

(images from tanzaniabirds, Arkive, IBC)

New World Primates 9: They came by night

2012-03-02T05:58:00.000-08:00

A.griseimembra

The last of the New World primates we have at Bristol can be found in Twilight World. The Grey-legged Dourocouli, Aotus griseimembra, belongs to a widespread group of monkeys which have, uniquely for higher primates, become nocturnal. There are of course numerous nocturnal primates in the Old World, incuding the bush babies of Africa, lorises of Asia, and many lemurs in Madagascar, but they all belong to a group generally referred to as the Strepsirrhine primates. These are distinguished from monkeys and apes, the ‘higher’ or Haplorrhine primates, by features of their face and skeleton, most obviously the moist, dog-like noses and tendency to rely more on scent and less on vision.

Strepsirrhine primates became extinct in the Americas, and when the ancestors of the New World primates colonised, probably by rafting from Africa across the then much narrower South Atlantic, they had already evolved into strictly diurnal animals. The nocturnal dourocoulis have re-evolved the ancestral primate condition of a nocturnal omnivore with a fondness for fruit. They do not exhibit much diversity however compared to the range of different nocturnal Strepsirrhines, probably because there were plenty of small nocturnal mammals in existence when they arrived, especially the large variety of opossums and frugivorous bats, which leave little ecological space for small nocturnal primates. As part of that adaptation, their eyes have become enormously enlarged, as can be seen on this skull:

A.trivergatus skull

The home range of a dourocouli family is extremely small, with densities of up to 16 groups per km2 being recorded, and they tend to use familiar routes around their territory, which probably helps them to remember familiar routes to and from their feeding and sleeping sites. The diet is mainly fruit, especially small fruits, but they also feed on nectar, leaves, flowers, and insects. Insects are usually large orthopterans and moths, but some other insects may also be taken. They are also prey themselves, and among their predators would be owls, snakes (especially boas) and various small carnivores such as the Margay or the Tayra. The large eyes on the owl butterflies in our butterfly house probably mimic these mammalian predators even more than they do owls in fact, and as owl butterflies are active at dusk they are probably important prey for dourocoulis.

Caligo atreus - dourocouli prey!

Although the range of the various species extends from Central America south to Argentina, they reach high altitudes in some places and in the Chaco region of Argentina even sub-zero temperatures are recorded in their range.

As monkeys, douroucoulis are not especially large, with the largest usually around 1.3kg. They seem to live in small family groups of an adult pair plus a few offspring from previous years. Youngsters stay with the adults until they are 2 or 3 years old, and females usually breed in the wild when they are 4 or 5 years. Lifespan is probably around 12 in the wild, more in captivity.

A.griseimembra family

As is common with New World primates, the male plays a major role in infant care, and once the infant is past a week old it is carried almost constantly by the male, only returning to its mother to feed until it is weaned at around 5 months old. Sometimes older juveniles will also assist, and as a result infant survival is extremely high – 96% has been recorded in wild Azara’s dourocoulis. Although captive dourocoulis are usually kept in permanent monogamous groups, in the wild both males and females are regularly replaced by intruders after serious fights which can even be fatal. The extreme support given by males to infants means that females have as much interest in acquiring a successful male as males do in attracting a healthy female, so the social structure is more even-handed than in Old World monkeys where most of the burden of infant care is carried by the females.

Nocturnal animals tend to rely on scent or sound to distinguish species rather than vision, and this has resulted in considerable confusion in their taxonomy, as even distantly related forms can look very similar. Until recently it was thought there were only 2 or 3 species, but in fact studies of chromosome number, detailed anatomy, and DNA have shown there are at least 11 good species and probably many more. Most of these have fairly large ranges and seem reasonably secure, especially as they can make use of disturbed forest fairly well, but a few species have tiny ranges and are threatened by deforestation. An additional threat has been collection for medical experimentation, as they are one of few species that are resistant to the deadly malarial parasite Plasmodium falciparum.

In captivity comparatively few zoos house dourocoulis, with A.griseimembra being the only one held in any numbers. Even that has under 100 individuals worldwide. Part of the problem is the general one of displaying nocturnal animals, but another problem has been the taxonomic problems of identifying which species a zoo actually has. In the past several mis-matched species pairings have resulted in sterile hybrids rather than useful parents of a new generation of captive dourocoulis, even though their husbandry in itself is not especially problematic.

This draws to a close this series on the New World primates at Bristol. Looking over the variety of different species, several themes can be picked out by which the New World primates differ significantly from those of the Old World:

1) A strong tendency for a more egalitarian social structure with females playing a far more central role than in most Old World primates

2) Much greater male input to infant care, especially transport of small babies

3) A lack of any significant terrestrial forms – as far as I am aware even in fossil forms there was never a New World equivalent to a baboon or macacque.

4) Much greater diversity in ecology, with miniaturization, gum-feeding, nut-eating, and other specialisations compared to Old World monkeys, which basically are either frugivores/omnivores or folivores.

The reasons for this diversity are not entirely clear, but I believe some of the reasons may include:

1) The different colour-vision in New World primates, with trichromatic vision being restricted to a subset of females, with males and other females having different forms of dichromatic vision. This means that each monkey in a group will see with different eyes, and be better at finding different types of food as a result.

2) A different set of competitors, both living and extinct. Until very recently terrestrial New World monkeys would have been in competition with a large set of forest herbivores such as ground sloths, glyptodonts and others, which may have restricted any evolutionary move to terrestrial feeding. The nocturnal marsupials may also have been too much competition for small nocturnal primates to survive.

3) Different biochemistries. The need for greater Vitamin D levels by South American primates may have limited their ability to move away from the equatorial forests into other habitats.

Next week, a new bird species at Bristol.

(Images from wikipedia, marwell zoo)

For more on dourocoulis, see the studbook here: http://www.marwell.org.uk/downloads/AotusStudbook2007_2010.pdf

New World Primates 8: Paging the wicked witch

2012-02-25T04:05:00.001-08:00

Male White-faced Saki

On one of the islands in the central lake live a family of one of the most distinctive of South American primates, the White-faced Saki Pithecia pithecia.The local name for these monkeys sounds like they would be more at home in the Wizard of Oz – they are called flying monkeys because of their prodigious jumps (up to 10m have been recorded). In the wild they have a wide distribution through the rainforests of South America, so they are listed by the IUCN as of Least Concern. Most of its closest relatives are also in reasonably good shape, although one, the Buffy Saki Pithecia albicans, is listed as Vulnerable.

Sakis and their relatives belong to a group called the pitheciids, and they have an unusual dietary specialisation. Unlike fruit-eaters, they do not act as agents of seed dispersal, instead being predators on seeds as they feed mainly on seeds, nuts, and unripe fruit, with some foliage and a small amount of animal protein in addition.

Plants take steps against their vital reproductive resources being destroyed in this way, and protect themselves with both physical defences and chemical protection in the form of toxins in unripe fruit and seeds. The pitheciids however have developed means of circumventing these to gain access to a food source other animals cannot use. Some of these take the form of anatomical modifications of the jaws and teeth to enable them to break open the husks and seeds, but they also use self-medication to combat the effects of ingested poisons. This medication takes the form of geophagy – eating clays and minerals to neutralise poisons and speed their removal from the body. This behaviour is well known in parrots, especially macaws, as they too are seed predators and face the same chemical challenges from their diet. The observations of sakis performing this behaviour have been of them eating the walls of arboreal termite mounds rich in kaolin, which avoids them having to risk descending to the ground.

Sakis move around in small family groups comprising an adult pair plus up to four offspring of various ages. They defend their territories with calls, especially a duet of the adult pair, which sounds rather bird-like. Their most distinctive feature is the great difference in appearance between adult males and both females and juveniles. This kind of difference is often associated with a haremic social structure, but white-faced sakis are apparently monogamous. Although groups containing more than one adult male are known, it is likely that the extra males are in reality mature offspring of the breeding pair. Young male sakis start to develop their adult appearance at around 2-years, prior to leaving their birth groups and starting families of their own. In the wild the lifespan is probably up to 15 years, longer in captivity as they are not exposed to predators.

Female White-faced saki with young

Currently ISIS lists around 350 in zoos worldwide, and they have a reasonably good breeding record. As with most animals in zoos these days, they are managed via a studbook – in fact there are two, one for North American animals and another for Europe. Bristol manages the studbook for Europe, and our pair breeds regularly, so we have sent young to other zoos all over Europe.

Although the sakis are not especially endangered, some other pitheciids are in a much worse state. Unfortunately, these forms are even more specialised than the sakis, and in common with many such animals, providing proper food and accommodation in captivity may be difficult. In common with many animals that live in the canopy of primary rainforest, living in a confined space close to ground level is stressful, and although visitors to zoos will notice the floor space of an enclosure, people tend not to pay so much attention to the height of an enclosure. From those husbandry manuals I have read, many tend not to even specify enclosure height, which I feel is a potential omission from good practise. While many monkeys, especially smaller ones, live their lives with 10m of the ground, other species definitely prefer to be as high as possible. The same is true of many forest birds, which will often choose the highest nest site available if they have a chance.

One of the most distinctive of the white-faced sakis relatives is the Bald Uakari, Cacajao calvus, which is unfortunately currently listed as Vulnerable by the IUCN. This is a much larger and more social species, with some groups being over 30 strong, but it is confined to flooded forest areas. As with most rainforest animals, deforestation is the major threat, closely followed by hunting. Few Uakaris have been kept in captivity, and even more seldom bred, because of their specialisations. The only ones in North America are at LA zoo, but I am not sure if they are on show.

Bald Uakari

Next week, we reach the final chapter in this series – a group of monkeys which have developed a unique behaviour for a higher primate, they are nocturnal. This has been the cause of some confusion as to how many there are, as I will talk about next time.

(Images from wikipedia, animal planet website)

New World Primates 7: Love Monkeys

2012-02-17T11:27:00.000-08:00

C.cupreus

It is a few days late, but it is appropriate that Valentine’s week should feature one of the most closely affectionate of the monkeys, the Red Titi Callicebus cupreus. Bristol currently has a pair, but people often walk past their enclosure because they are also among the most secretive of monkeys. Their preferred habitat is dense tangles of vines, edge forests, bamboo groves and similar habitats, where they can go about their lives undisturbed. Unlike many other species, they avoid other primates and do not move around in mixed associations, instead pursuing their lives in small family groups of a pair plus up to three offspring.

As with most larger primates, they specialise in fruits but will happily eat anything with food value, including insects and leaves.. They have not as far as I am aware been seen feeding on gum or sap, but almost anything else is on the menu – an escaped animal in the US was observed to eat acorns among other things, so nuts are probably also part of the wild diet. Unfortunately our female has diabetes, a common complaint in captive primates, and is probably due to being fed commercial fruit with a high sugar content compared to the fruits usually eaten by wild animals, especially mammals. These days the sugar content of the diet of all frugivorous mammals in captivity is carefully watched, but fruits similar to those eaten in the wild are quite hard to provide, so artificial diets are becoming increasingly common.

Secretive animals like titis do not make especially good exhibit animals, and as a result the captive population of tits is small. Of the numerous species, there are only two with even potentially self-sustaining captive populations, and the AZA in the US and EAZA in Europe have decided to focus on one each. In Europe the species is C.cupreus cupreus, a subspecies of the Coppery Titi, whereas in the US it is C. donacophilus, the White-eared Titi.

C.donacophilus with tails entwined

As with many South American primates, males are heavily involved in infant care. The infant transfers to the male for transport shortly after birth, and until it can move independently is only returned to its mother for feeding. Sometimes older juveniles will also help carry their siblings, but this has not been observed very often, unlike in callitrichids where it is standard behaviour. Young remain with their families until 2 or 3 years old, then disperse to find mates of their own. Once paired, male and female are extremely close, spending long periods of time in physical contact and appearing highly agitated if separated from each other. Communication is maintained in thick vegetation by a series of very complex vocalisations, whose meaning is not yet elucidated.

There have been very few studies of predation on wild titis, but birds of prey are likely to be the major enemy. Large snakes such as boas would certainly take them, but medium sized carnivores such as Tayra and Margay could also take them, especially at night when they are asleep in vine tangles or tree holes.

Margay

As with all forest animals, the biggest human threat to titis is deforestation. As long as the removal of trees is not too excessive however titis can cope with disturbed habitats quite well, as the dense vegetation of regenerating abandoned farmland suits them. Even so, at least one species, the Blonde Titi C. barbarabrownae is classed as Critically Endangered. Its wild population is estimated as perhaps as few as 250 animals, which makes it even rarer than the famous Lion Tamarins which live in the same Atlantic Rainforest of Brazil.

I mentioned that there were numerous species of titi earlier. As with many primates, it now appears they are far more diverse than was first thought, and where there were once believed to be only 4 or 5 species, the count today is probably nearer 20. As the different species occupy different forests, from rainforest with seasonal flooding to dry woodland edge in some species, there is an urgent need for studies into their ecology, which may be more variable than we think.

Next week, a dietary specialist, the White-faced Saki

(images from wikipedia)

New World Primates 6: Howling for help

2012-02-12T14:55:00.000-08:00

One of the South American monkeys Bristol has been most successful with is one of the most resonant voices of the rainforest, the howler monkey. The IUCN red list has a total of thirteen different species, which are found from Central America as far south as Argentina, wherever there is suitable forest. The species we have at Bristol is more or less the only one likely to be seen outside a South American zoo, the Black and Gold Howler Alouatta caraya. They get their name from the sexual dimorphism in the species – adult males are jet black while females and juveniles are golden brown.

Female A.caraya

Most of the howler monkeys have fairly large ranges, and can survive in fairly small pockets of forest, but a few are only found in very small areas and as a result are at risk from hunting pressure and deforestation. Two are listed as Endangered, the Yucatan Black Howler monkey A.pigra and the Maranhao Red-handed Howler monkey A.ullulata.from Brazil. The main threats from humans to howlers are hunting – they are important subsistence prey everywhere they are found- , and habitat alteration, especially deforestation and dams. Howlers can swim, but are very reluctant to do so, and the ranges of the various species are defined by major rivers.

Howlers are very heavy-bodied animals, and are not very agile, especially compared to their close relatives the Spider monkeys. Males are much larger than females, with an average mass of 6 to 8 kg, with females usually around 5kg. Rather than hanging from slender branches and reaching out to pick fruit, howlers are specialist in feeding on leaves. As these take far more digestion to extract nutrients, howlers give the impression of being more sluggish, and sleep up top 70% of each day digesting their food. As a plus however, because they do not need to travel long distances in search of ripe fruit, they can survive in small forest areas at very high densities, with home ranges as small as 0.1 sq.km for an average sized troop. They sometimes descend to the ground, but most of their time is spent high in the canopy.

Howler groups vary in size, but typically comprise 1-3 adult males, a similar number of females, plus offspring. Usually only a single adult male breeds, and the subordinate males may in fact be older juveniles who have not yet dispersed to found groups of their own. Eventually almost all males and a majority of females will emigrate from the natal group. Juvenile males may band together to form bachelor groups until they can either attract females or take over an existing group by defeating the resident alpha male. As in many other animals with a similar breeding system, take-overs are usually followed by infanticide of small infants. In one study of Red howlers more than 44% of infant mortality was due to infanticidal attacks.

The group defends their territory by the dawn chorus of their howls, which can carry several kilometres. Both males and females will join in the group howls, but males are much louder as a result of an enlarged hyoid bone, which supports the resonating chamber in their throats. When not howling, they are surprisingly silent creatures, and do not spend a lot of time in socialising even within the group.

Harpy eagle in flight

A large, slow-moving animal is quite vulnerable to predators, and although howlers can defend themselves against most mammalian predators large birds of prey, especially the world’s largest eagle, the Harpy Eagle Harpia harpyja, are a major threat. Perhaps as a result, howlers are surprisingly prolific for a large monkey, and at Bristol the interval between births has been as short as nine months. The young mature fast, with females having their first infant around 4 years, but males not being in a position to breed until nearer seven. Lifespan in captivity is around 20 years, probably nearer 12 in the wild.

One very odd feature of some species of howler monkeys is that their sex chromosomes have a different pattern to those found in all other mammals. As a standard pattern, mammals have a standard arrangement where females have an XX and males an XY pair of chromosomes in addition to the autosomes which carry the bulk of the genetic material. In A.fusca there is a much more complicated arrangement where there are two different types of X chromosomes, X1 and X2, and there is variation in the diploid number, with the result there are at least four different possible karyotypes, XY/XX; X1X2Y/,X 1X1X2X2, X1X2Y. Some other species of howler monkey have similar variations. There may also be differences in the number of autosomes, so the diploid number of an adult howler can vary extensively. Whether the variation has anything to do with the odd sex-linked colour vision variation in New World primates I talked about in an earlier post is not clear.

In captivity howlers are not often seen compared to many other monkeys. Their status as slow-moving prey animals means they tend to be quite nervous, especially when they cannot retreat as high as possible, and the Black and Gold howler is the only one with a regularly breeding captive population, with around 250 animals in zoos worldwide. This population took a long time to establish, as wild-caught howler monkeys are very prone to stress-related diseases and seldom breed. The captive population of Black and Gold howler has enabled some elucidation of best practise in husbandry, especially housing and diet and the species is now managed genetically – in fact Bristol holds the EAZA stud book for this species. Even though we bred then successfully for many years, as soon as their new enclosure was built they took to spending as much time at the top of the enclosure as possible, and hardly ever come lower than 2m off the ground. This is especially obvious when the zoo is busy and there are crowds around their enclosure. They have in some zoos been kept with other primate species from their range, but seem easily intimidated, even by much smaller species such as tamarins.

The diet of howlers also requires special consideration. In the wild they can eat many hundreds of different plants, especially the leaves although they take some fruit. The captive diet is a specially formulated high-fibre biscuit, supplemented with browse (cut branches and leaves of various trees and shrubs), plus various leafy vegetables and some other green vegetables such as beans or okra. Even with fruit-eating primates, recent thinking in zoos is to avoid commercial fruit in their diet, the reason being that fruits bred for human consumption are far too high in sugar compared to wild fruits, and are a cause of diabetes and tooth decay in many species.

As a result of these difficulties with maintaining captive howlers, there is no co-ordinated captive breeding programme for the endangered howler species, and protection in the wild is likely to be far more effective and easier to carry out than ex-situ conservation breeding. Nonetheless, studies on the captive population is extremely useful for throwing light on the social organization and exact requirements of wild howlers, which could be vital in the future. Although zoos tend to headline captive breeding and release as the main goal for their keeping various animals, research is at least as important, as we cannot conserve a species in the wild unless we know what it actually needs, and a captive study population is often the easiest way to obtain vital information.

Next week, one of the many medium-sized monkeys of South America, the Red Titi.

(Images from wikipedia)

New World Primates 5: Squirrel Monkeys

2012-02-04T02:50:00.000-08:00

S.sciureus

On one of the islands in the lake can be found our group of a very familiar, but little understood, small monkey, the South American Squirrel monkey Saimiri sciureus. Squirrel monkeys are widely spread throughout central and South American rainforests, but until recently it was thought that there were only two species, The South American S.sciureus and the Central American S.oerstedti. More recent work has elevated some subspecies to specific status, and identified other new forms, with the result that there are now considered to be at least five species, some of which themselves may contain several subspecies.

S.oerstedti

This causes some problems in analysing past studies, as the different species differ in important aspects of their behaviour, especially group size and breeding patterns. In the captive population, several subspecies or even species may have been hybridised, which may account for some of the problems experienced in captive breeding. At Bristol our group is believed to be pure S.sciureus sciureus, the nominate subspecies. The various forms differ slightly in size, but the most obvious difference is in the shape of the ‘V’ between the eyes as the darker fur of the crown of the head points down. In S.sciureus this is a very distinct and narrow ‘V’ whereas in S.bolivensis it is much shallower.

S.bolivensis

In the wild, squirrel monkeys are mostly found in lowland tropical forests, all though in some areas they range to an altitude of 2000 metres. They are habitat generalists however, and can live almost anywhere there is sufficient food sources, especially edge forests or abandoned farmland with regenerating woodland. In fact, untouched primary forest with a mature canopy often has lower densities than areas with at least some human disturbance. As long as an area is not heavily felled, the main problem is logging roads – squirrel monkeys are very reluctant to descend to the ground and will not leap gaps over 2m, so roads cut through the forest can seriously disrupt their habitat.

S.vanzolinii

As with many monkeys, squirrel monkeys will eat almost anything, but the bulk of their diet is fruit – as with most monkeys, they are important seed disbursers. Their animal prey is mostly insects, especially grasshoppers and caterpillars, but they also eat birds eggs, frogs, lizards, and even bats, which they catch at their roosts in trees or under leaves. Because they feed on smaller fruits and can forage further out onto branches, they can associate with other monkey species without much competition, and consequently benefit from travelling in company with them for protection. Capuchin monkeys (to which squirrel monkeys are closely related) are favoured companions, and as capuchins are powerful, aggressive, and highly intelligent they provide much-needed protection. An animal the size of a squirrel monkey has many predators, especially birds of prey and snakes, so it needs all the help it can get.

S.sciureus

The various species of Saimiri differ widely in their group structure, which is probably due to the different food types available to them. The most social species is probably S.bolivensis, which is found in groups of up to 75 or more animals (one troop of 300 was reported). By caontrast, S.sciureus lives in groups of 15-30 animals, and at much lower densities. The relations between males and females differ greatly as well, with males in S. bolivensis subordinate to the females and mostly on the periphery of the group as it moves, whereas S.sciureus has a fully integrated multi-male/multi-female group with a strong hierarchy incorporating both sexes. How young animals disperse also differs, with males remaining and females dispersing in S.oerstedti, females remaining and males dispersing in S.bolivensis, and both leaving in S.sciureus. This variation in social behaviour is another issue with management of captive Saimiri species, as the best way of integrating new individuals can be very different depending on the species involved.

Squirrel monkeys are seasonal breeders, with all the females in a troop giving birth within a few weeks of each other. Prior to the breeding season, males undergo a remarkable physiological change called ‘fatting up’ when they put on a lot of weight – up to 20% of their normal weight. As there is intense competition among males for mating rights, this weight gain is vital to their success, in the same way that bull seals put on a lot of weight prior to the breeding season at their rookeries. Squirrel monkeys reach maturity at 2-3 years and can live up to 20 in captivity, but probably nearer 10-15 in the wild.

As a result of their adaptability, most squirrel monkey species are less vulnerable to human modifications of their forest than some other species, but at least one species, S.ustus, is classed as near Threatened by the IUCN as a result of deforestation. S.ustus has the smallest range of any of the Saimiri species, and is consequently more at risk. It is alsoone of the least studied, and its own unique social structure is little understood. Other human threats to squirrel monkeys are capture for the pet trade, both internally and internationally, and use in medical research (it is one of the commonest laboratory primates).

Even though squirrel monkeys are widely kept, the captive breeding record is pretty poor. The main cause is probably the size groups they are kept in – they do not often breed successfully in groups of under 15 animals, even for S.sciureus, and for species with larger group size such as S.oerstdti and S.bolivensis the groups probably need to be at least twice that size. To compound the problem, smaller groups seem to be more likely to produce male offspring. These kind of effects occur in many other animal species, and is probably a result of stress hormones differentially affecting pregnancy success in male and female embryos. It is notable that the most successful groups, with the most female offspring, are large and long-established groups. From the lifespan of captive animals, the dietary requirements seem to be mostly met, but the social requirements are harder for zoos, especially small ones, to meet successfully owing to the large number of animals that must be maintained.

Next week, a much larger monkey – the Black and Gold Howler, one of the species we have been much more successful with.

(images from primateinfo.net)

New World Primates 4: Brown Spider Monkey

2012-01-27T12:53:00.000-08:00

A.hybridus

As you enter the zoo, the first large enclosure you encounter contains two young male Brown Spider Monkeys, Ateles hybridus. This Critically Endangered monkey originates from Columbia, where it lives in an ever decreasing area of primary rainforest.

Spider monkeys can be thought of as the ecological equivalents of the apes (especially the gibbons) of the Old World – large bodied fruit eaters with complicated societies. They spend almost all their time high in the canopy on a continuous search for fruit of numerous species, and are very important seed dispersers as a result. In hard times they may also eat leaves, some insects, or even decaying wood, but without an extensive variety of fruiting trees they cannot survive for long.

A.fuscus feeding

The most obvious feature of any spider monkey is the long prehensile tail. This enables them to gather fruit with both hands, as the tail can grip well enough to support the 9-10kg weight of the whole animal. They will also brachiate, or run through the trees on all fours. This enables them to cover considerable distances when needed with minimal energy expenditure. Many South American monkeys have tails that are prehensile to some degree, but the Spider Monkeys are undoubtedly the supreme examples of this feature.

The society of spider monkeys is much more complex than one might think. In a fashion somewhat similar to chimpanzees, they have a ‘fission-fusion’ society, with a group comprising 20-30 individuals at any one time. This group however does not move around in a body, instead much smaller bands of 2-4 individuals, usually with a single adult male, move around and meet peaceably with other subgroups as they encounter each other. Different groups show more aggression, but this is usually vocal rather than physical, and it is not unknown for females to transfer from one major group to another and then return to their home band.

As part of this social structure, spider monkeys do not show the disparity in size that is common in primates where a dominant male monopolises reproduction. Males are slightly larger, but the difference is hard to observe from the ground. The fission-fusion structure is probably an adaptation to maximise the use of widely scattered fruit sources, which can only sustain a few animals the size of a spider monkey at one time. Also, there is no obvious automatic male dominance – both females and males may take precedence in a group, depending on the individuals involved. This lack of male dominance is a feature of many South American monkeys, which are far more variable in their social structure than Old World monkeys are.

Part of the reason for this difference may be the polymorphism in vision in New World monkeys, which means that some females may have superior fruit-finding skills than other females and males. Colour vision in primates is the result of opsin pigments in retinal cone cells, which can be sensitive to Short (S), Medium (M) or Long (L) wavelengths. The S pigment is common to all primates and other mammals, and is held on an autosome. The M and L pigments are produced on the other hand by genes on the X chromosome. Old world primates have a duplication of the pigment genes, and normally carry both an M and an L pigment gene on each X chromosome. New World primates have only space for a single gene, which may be either an M or an L pigment. As male mammals are XY, and only have a single X chromosome, whereas females are XX, this makes for the situation as follows:

Male spider monkeys: SM or SL opsins
Female spider monkeys: SML, SLL, or SMM opsins

Females with the SML configuration are the best at colour discrimination, important when searching out coloured fruit of the best quality. Other configurations may each have their own advantages, but it is not clear what they may be. Any advantages of one type over another may only be temporary, perhaps at particular seasons. All the South American primates seem to exhibit this variation, so it has obviously worked for at least 17 million years, when it is believed the ancestral form began to diverge into the variety of species we see today.

Unfortunately, the need of spider monkeys for primary rainforest is a major cause of their current status as endangered animals. An effective breeding population needs a large area of untouched forest, as they cannot make use of secondary forest in the way that smaller species such as marmosets can. They also have a very low reproductive rate, with an age at maturity of at least 5 years and an interval between births of 2-3 years. As a result, any loss of a population cannot be replaced easily, and many species are quite heavily hunted.

The two young males we currently have at Bristol are part of the globally managed breeding programme for this species. It is hoped that females may join the group as they become available, but the captive population of this species is small (only around 85 animals worldwide) and reproduction is slow as mentioned above. With a long lifespan – potentially over 40 years- there is however time to find a suitable mate. With the ongoing deforestation and hunting in Columbia however, the need for protection in the wild is dire. The well known political problems do seem to be being gradually resolved, but by the time the Columbia people, or at least their politicians, take effective action it may be too late. As far as Bristol Zoos’ influence is concerned, we are gradually getting more involved with conservation projects in the country, and in particular with husbandry and veterinary help in rescue centres and Columbian zoos, as I described last week.

Nect week, a much smaller monkey – the Squirrel Monkey, which also has a more complicated society than you might expect.

(images from wikipedia, Arkive)

New World Primates 3: Silvery Brown Tamarin

2012-01-21T15:24:00.000-08:00

As well as the animals we have on show at Bristol, the zoo supports numerous conservation projects around the world. One of these is for a rare Columbian monkey, the Silvery Brown Tamarin Saguinus leucpos.

Columbia is second only to Brazil in terms of biodiversity, and no less than 37 different species of primate are found within its borders. With the destruction and fragmentation of forest cover, many of these species are increasingly threatened, especially those with small geographic ranges. The Silvery Brown Tamarin is found only in the Central Magdalena valley, and none of its range is inside a protected area at present. It is also the target for a large internal pet trade in wild caught animals, and is currently the most confiscated animal to be found in Columbia rescue centres. Historically, survival rates have been very poor, as a result of lack of knowledge of their requirements and capture stress (many species of marmoset and tamarin are very sensitive to this). As a result of this, the population in the last 18 years is estimated on the IUCN Red Book to have declined by over 50%, and it is classed as Endangered.

In 2006 Bristol and other European zoos in the Callitrichid Taxon Advisory Group began a cooperative venture to foster the conservation of the tamarin. Efforts have been focussed on studies of animals in the wild, and improving care and possible captive breeding programmes in both Columbian and other zoos. So far seven zoos in Columbia hold the species, and there have been some births, but work still needs to be done. Experience with the Lion Tamarins shows that this kind of programme can be successful, but is a long struggle to get to a point where the species can be reintroduced to the wild. Columbian law is rigid in the regulations concerning the transfer of any of the rescue animals out of the country, so we are unlikely to see them at Bristol any time soon – we will have to wait until animals at least 2 generations from the wild founders are available. I have however found a film of one on Youtube here: http://www.youtube.com/watch?v=G5vW6n148N8

Despite their high diversity, the various small callitrichids have fairly similar social structures. A group will be centred around a single breeding female and her mate, plus offspring of various ages. The young are carried by the adult male and their older siblings until they become independent at a few months old. The main difference between marmosets and tamarins lies in their feeding ecology – marmosets have specialised dentition which enables them to gouge grooves in the bark of trees to release sap and gum, which are major components in their diet. Tamarins lack the gouging jaws, so can only use pre-existing wounds in trees as a source of this food. Aside from this, both groups feed heavily on insects, especially orthopterans, and also catch frogs and lizards, and raid birds nests. They will also take some fruit, and where forest edge meets agricultural land they will raid fruit trees. Differences between species, which often move in mixed species groups, centre on the proportions of the various dietary elements and the parts of the trees from forest floor to canopy that they use.

In captivity, most marmosets are now supplied with a diet that is tailored to meet nutritional needs. Developing a diet for a captive animal is quite a tricky process, as even when you know what an animal feeds on in the wild you generally do not have enough knowledge of how the wild food source compares nutritionally with that available in captivity, even if for example you are feeding the same plant, as growing conditions, soil composition, even the time of year can all affect results. The Callitichid husbandry manual has a long chapter on diet for callitrichids, which lists nutrient requirements as follows:

Nutrient Concentration in diet*
Energy (kcal/g) **
Crude protein (%) **
Fat (%) —
Fiber (%) —
Linoleic acid (%) 1
Vitamin A (IU/g) 14
Vitamin D (IU/g) 2.2 or less
Vitamin E (mg/kg) 56
Thiamin (mg/kg) 5.6
Riboflavin (mg/kg) 5.6
Niacin (mg/kg) 55.6
Pyridoxine (mg/kg) 2.8
Folacin (mg/kg) 0.2
Vitamin B12 (mg/kg) 0.6
Pantothenic acid (mg/kg) 16.7
Choline (mg/kg) —
Biotin (mg/kg) 0.1
Vitamin C (mg/kg) 500 or more
Calcium (%) 0.6
Phosphorous (%) 0.4
Magnesium (%) 0.2
Potassium (%) 0.9
Sodium (%) 0.3
Iron (mg/kg) 200 or less (80-200)
Zinc (mg/kg) 11.1
Copper (mg/kg) 1.5
Manganese (mg/kg) 44.4
Selenium (mg/kg) —
Iodine (mg/kg) 2***

* Probable requirements for New World primates. Depending on the interpretation of the NRC (1978), the requirements for magnesium, iron, and manganese may be overestimated.
** The requirements for these nutrients are higher for marmosets and tamarins than for other New World primates. Energy required is 150-160 Kcal/Kg body mass/day (d) (Morin 1980); protein for small primate species is 3.5- 4.5 g/Kg body mass/day of high-quality protein (NRC 1978); vitamin D3 required is 110 IU/d/100 g body mass (Takahashi et al. 1985).
*** NRC may have overestimated the quantity needed. For most other animals the requirement is about 0.1.
— No NRC requirement stated for this nutrient. This does not mean there is no requirement, just that studies have not been performed. For selenium, the level in many mammals is about 0.1 ppm.

With this as a basis, several different usable diets have been formulated. As marmosets have been used as laboratory animals, specialised commercial diets are available which can be adapted to other callitrichid species. Examples of these diets can be found in the husbandry manual, which is available here: http://nwptag.com/Download%20Text.htm. Even this has a lot of space for variation – for example ‘fruits’ in a captive diet in the UK will usually be apple, pear, grape, or other similar plants grown in the UK. In the native Columbia, fruits available in a typical market might include guava, prickly pear, passion fruits (of several species), cherimoya, papaya, tomatillo or many others. How these compare and interact with other diets is a major research item for an animal collection, and nutritionists are still developing recommendations. For example, high dietary vitamin C in birds and probably some mammals promotes iron absorption, which can lead to liver problems in animals used to low iron diets in the wild.

For the Silvery Brown Tamarin the year has started well, with the association of South American Zoos and Aquaria (ALPZA) accrediting the programme as a cpnservation leader for South American zoos. For more information, check out the ALPZA website at http://www.alpza.com/

Next week, we move on to the larger primates, starting with one of the most iconic of South American monkeys, the Spider Monkeys

Information and images from Bristol Zoo website, ARKive, ALPZA

New World Primates 2: Lion Tamarins

2012-01-14T02:25:00.000-08:00

Golden Lion Tamarin

Here at Bristol we currently have on show two of the four living species of Lion Tamarins, leontopithecus. These are a now aging pair of Golden-Headed Lion Tamarins L. chrysomelas, and more importantly a growing family group of Golden Lion Tamarins, L.rosalia. The other two species are the Black Lion Tamarin L. chrysopygus and the Black-faced Lion Tamarin L. caissara.

Golden-headed Lion Tamarin

The various forms of Lion Tamarin were once found in Atlantic rainforest all along the coast of Brazil, but development of the area (the most densely populated part of the country) has caused major habitat loss and fragmentation of the habitat. By 1992 they were found only in a total area of 104.5km2 of forest in three regions of Rio de Janeiro province, with under 600 individual known. After 30 years of intensive conservation efforts, this number has been raised to over 1,000 in the wild, which is still far too low for long term survival without intensive help and population management. Captive bred individuals have been reintroduced to the wild, and in fact about 1/3 of the wild individuals have at least one captive bred ancestor, but the ongoing problem is still the fragmentation of the habitat.

Black Lion Tamarin

Each family group of Lion Tamarins needs between 40-100 ha of rainforest. They are actually fairly adaptable in their habitat selection, and are well able to make use of secondary and degraded forest as long as there are sufficient resources and especially tree holes they use as sleeping quarters. They are quite omnivorous, feeding on fruits, flowers, plant exudates, insects, and also catching frogs, lizards, and sometimes birds. There nearest ecological equivalent in the Old World monkeys would be a sort of miniaturised macacque.

Black-faced Lion Tamarin

As with almost all the callitrichids, they have twins at each birth, sometimes triplets. In captivity they can have litters twice a year, but in the wild they seem to have only one, probably as a result of food scarcity during the dry season. The babies are actually carried by the father or older juveniles in the group, returning to the mother to feed.

The group dynamics of Lion Tamarins are quite interesting. A single animal is at extremely high risk of predation, so they are extremely dependent on family groups. Typically these are a single pair plus offspring, but cases where there are two adult males (usually brothers) or two adult females (usually a mother and daughter) are also known. Young disperse at around three years, but if an adult female dies one of her daughters may inherits the territory. Both males and females may leave to try and set up their own families, but males are much more successful at immigrating into groups than females are. When males leave, it is common for two to leave together for mutual protection. They may try to evict a male from an existing family, or try to get a dispersing female to join their groups. As they are so rare, there is still much to be studied in their behaviour, and it is not entirely clear what the ‘normal’ structure of their society is in some cases.

One of the oddest features of the biology of the marmosets and tamarins is a result of their tendency to produce multiple births. As with other monkeys, they have a simplex uterus, with gestation taking place in a single central horn (by contrast, dogs have a bicornuate uterus). With multiple foetuses developing in a single uterus, the placentas of the twins or triplets fuse, and cells can pass between them. As a result, baby tamarins are chimaeric, with cells from two separate fertilized eggs forming their bodies. This is true even if the twins are of different genders, and both XX and XY cells can be found in the blood of each twin from a mixed litter. Whether this just affects blood and bone marrow, or possibly other parts of the body, is not yet clear and may in any case vary between species.

In addition to the wild population, there are around 400 Golden Lion Tamarins in zoos around the world. In the UK, standard accommodation is a heated indoor house with the nest boxes, and access to a planted outside screen cage or lake island. This enables the group to forage for insects and other prey as they would in the wild, and improves their general level of activity. In some places they can even be kept at semi-liberty. The habit of callitrichids of always sleeping in the same tree hole means that an established family group will always stay close to home base without additional confinement. In the past Bristol had a group of Geoffroys marmosets running loose in this way, and they bred successfully, but unfortunately as the group size grew they decided they needed more room and one summer evening left the zoo grounds. After that they had to be confined for their own safety. In zoos with more extensive woodland areas they have had more success, and if you visit Jersey you can walk through Tamarin Wood and find them running past you on the fence.

There is one more marmoset to cover before we move on to the next group of South American primates. This is one we do not yet have on show, but are working with in the wild – more on that next week.

Sources: IUCN, Primateinfo.net, wikipedia, Bristol zoo)

New World Primates 1: Goeldi's marmoset

2012-01-07T10:16:00.000-08:00

Mother carrying baby - December 2011

I am going to start 2012 with a series on the eight species of New World Monkeys we have here at Bristol. Between them the species Bristol holds covers all five families of the Platyrrhine monkeys, the scientific term for the monkeys of Central and South America. Their ancestors are believed to have crossed the Atlantic from Africa around 40 million years ago, and they have either developed or retained several adaptations that distinguish them from the monkeys and apes of the Old World. They do not have as good colour vision as Old World monkeys for example, with only two colour sensitive cone types in the retina in males, and either two or three cone types in females. In addition, their physiology is different, and they require much higher blood levels of Vitamin D than Old World monkeys do. Before this last requirement was realised, it was hard to maintain Platyrrhine monkeys in good health at high latitudes, even with exposure to sunlight, as they were very prone to Vitamin D deficiency diseases.

The first of our monkeys I am going to cover is surely one of the cutest, the Goeldi’s marmoset Callimico goeldii. In December our pair had another baby, bringing the family group to six. Goeldi’s are rather untypical marmosets, and appear to have adapted to a habitat and lifestyle somewhat different to the other marmosets and tamarins of South America. They exist at low densities throughout their range, and often associate with other species as they range around their territories. They prefer a densely vegetated understorey, usually staying under 5m from the ground, and streamside vegetation, regenerating secondary forest (including abandoned farmland) and bamboo seem to be preferred. The range extends from northern Bolivia into southern Columbia, east of the Andes.

Feeding on a Morpho butterfly

Most marmosets feed heavily on insects, especially grasshoppers, katydids and phasmids, and Goeldi’s are no exception. However, they differ in not feeding much on saps and gums, instead feeding heavily on various fungi, especially in the dry season. Other important dietary items are fruits and small vertebrates such as frogs and small lizards, with birds’ eggs when available.

Marmosets are highly social creatures, and Goeldi’s fit the general pattern – a single breeding pair plus offspring of various ages. The group size is smaller then their relatives, with usually 6-10 animals in a group. There is some variation, as both polyandrous and polygynous groups have been observed. The territory size can be as much as 1.5km2, several times the size of that of other marmoset species.

Most marmoset species have twins sometimes even triplets at each birth, and when resources are available can have two litters each year. Goeldi’s are much less prolific, with only a single youngster at a time and in the wild at least often only a single baby each year. This probably reflects the lower energy and mineral resources in their diet, and also the energy expenditure in getting around much larger territories. They may also experience less predation than the more visible marmosets, who often feed at higher levels in more exposed positions.

An animal the size of a Goeldi’s marmoset has numerous enemies of course. Mammalian predators are probably not the main enemy, but birds of prey and snakes are probably much more serious threats. I am not aware of any studies on the issue, but Goeldi’s have at least 40 recorded calls, and it is probable that some alarm calls are specific to the type of predator being observed. Many species that have such alarm calls, from Vervet monkeys in Africa to prairie dogs in North America and even some pheasant species in Asia have such predator-specific calls. Given that they associate with other marmoset and tamarins it would not be surprising if they can also understand the alarm calls of their companion species as well.

The main threats to Goeldi’s today are probably those related to development and deforestation. They will have trouble crossing roads, and this can cause fragmentation of their territories and the isolation of non-viable groups in small patches of forest. On the other hand, their ability to utilize secondary regrown forest can count in their favour.

The various species of marmoset and tamarin make good exhibit animals, being sociable and diurnal, and around 500 Goeldi’ marmosets are listed on ISIS. The typical exhibit in the UK will comprise heated indoor quarters with access to either a screen cage or sometimes an island. Access to planted enclosures is highly beneficial where possible, as it provides opportunities for natural behaviour and especially foraging for insects. The captive diet is a variety of fruits and vegetables, combined with a proprietary prepared biscuit and added insects in the form of mealworms, locusts, and crickets.

Next week: Lions tamarins – beauties from the Brazil!

(images from Bristol Zoo website, wikipedia)

Goodbye Mum

2011-12-31T08:36:00.000-08:00

The last post of this year is a sad one for me. In October my mother passed away after being diagnosed with cancer some years ago. She could stay at home up until only a few days before she died, and fortunately was able to look after herself, with some help, more or less to the end. I will always be grateful to her next door neighbour who helped her so much, and to the hospice where she spent her last days and whose outpatient day centre she so enjoyed visiting.

Mum was born in London in 1924 and was a keen Girl Guide. She should have been on a trip to Switzerland when WWII broke out – she was very annoyed at this and much enjoyed travelling in later life. I once said she should leave an itinerary letting us know which continent she was on! We have relatives on her side of the family in Australia and New Zealand – in fact a relative of hers, William Burton, was the last surviving member of Scot’s expedition to the Antarctic when he died just short of his 100th birthday in 1988 (he was a stoker on the Terra Nova). I am glad to say Mum and Dad met him in Christchurch before he died.

When war broke out Mum was evacuated to a safer location. Unfortunately, the evacuation plans were not exactly well thought out, and she was evacuated to Luton, opposite the Vauxhall works that were turning out munitions! As soon as she could, she left school and returned home. Given a choice of working in a munitions factory or for the post office, she chose the post office and spent the war years in a typing pool in central London, volunteering with the Red Cross and spending some nights in London underground stations during the blitz. She never spoke much about the war years to me, except that at one of the buildings she was working at the chief safety warning was to stay away from the glass doors during an air raid. The blitz itself lasted for eight months and by the end of it one million London houses were destroyed or damaged, and 40,000 civilians had been killed. In 1944 there was another series of bombings by V2 rockets, the first ballistic missiles, which lasted until March 1945, which killed and injured several thousand more people.

Meanwhile, my father was also working for the post office in London, though their paths didn’t cross then – they met on holiday in the Lake District after the war, and married in 1949. Mum worked as a secretary with various solicitors, typing complicated legal documents that had to be right first time – no corrections allowed!

Dad was working for the Crown Agents and was sent to their Washington DC office in 1956 for a year. It must have been quite difficult for Mum, living with a toddler in a flat with no air conditioning and cockroaches! However, she enjoyed the trip and made some good friends there. Some years later the whole family went on a second posting to Washington DC, this time for two years.

When dad retired they moved to Fordingbridge, just south of Salisbury, but Dad died of a heart attack when he was 67 (he was a fairly heavy smoker). Mum was still driving ‘old dears’ as she called them to community lunches when she was 80, and often volunteered at Fordingbridge museum.

One of her biggest interests was the W.I. She was a member of the Sanderstead branch, and naturally joined Fordingbridge WI after their move. (insert details of roles taken)

Mum was always determined to make the most of life. She enjoyed many great holidays with friends; loved cooking and needlework of different kinds; and was always delighted to see the family. She loved spending time with her grandchildren, who remember her gift for light verse, making up poems on different subjects. This was something she always enjoyed; in fact she was very annoyed when a poem she helped my sister write for homework only received a B+! She loved going out for meals and became a bit of an expert on local pubs, probably because of all those W.I. walks! We were all very grateful that she was well enough to attend my niece’s wedding in May, an event which she was determined to see and which she loved looking back on afterwards.

That closes this years’ series of posts. In the New Year, pheasants, marmosets, wild birds, and conservation projects will be among the topics covered. Please leave comments or make requests for any animals you would like posts on!

Review of 2011 - Part 2

2011-12-28T02:32:00.000-08:00

Gorilla statues at Bristol Harbourside

11th July marked the zoos’ 175th birthday, having opened on that date in 1836. In its early days, the Zoo received the gift of a lioness from Queen Victoria, and in 1868 the Maharajah of Mysore sent over Zebi the Asian elephant, which became renowned for removing and eating straw hats! Rajah, who gave rides to children for many years, replaced her.

Bristol Zoo also found international fame in 1934 when Adam, the first chimpanzee to be conceived and born in captivity in Europe, was born. Another well loved character was Alfred the gorilla, who lived at the Zoo from 1930 to 1948. Alfred was, at the time, the only gorilla in captivity in the country and was a very popular Bristol citizen.

Many people also have particularly fond memories of Rosie the elephant, who gave rides to 80,000 children a year throughout the 1940s and 50s; Roger, a black rhino, who was the first rhino ever born in the UK, in 1958; and the Zoo’s more recent elephants, Wendy and Christina who were taken for walks to Whiteladies Road during the 1960s.

Even those who lived too far to visit Bristol Zoo got to know some of its inhabitants as they found fame with Johnny Morris’ popular television series, Animal Magic, broadcast from the Zoo during the 1960s.

For Bristol, July also saw the launch of the Wow! Gorillas campaign, in which 60 fibreglass gorilla sculptures painted by a variety of artists were placed all over the city for the summer. This was a great event, and enormously popular with the local press, as a lot of people made a point of visiting each one to have their photo taken with them.

Greater Flamingos with chicks

August saw the hatching of the ninth flamingo chick of the year. We eventually managed to raise seven to independence, including two that were hand reared by the keepers.

New Stream Garden

September kicked off to a good start with the zoo winning the Bristol in Bloom gold medal. The award reflects the whole Zoo, as the judges not only take in to consideration the landscape, but many other factors such as cleanliness and recycling initiatives.

Judges gave particular credit to the Zoo’s new stream garden area that opened earlier this year. The gardening team made the area as interesting as possible by including a variety of features, including a stream, pond, aviaries, stumpery and a variety of plantings, such as poppies, peonies and roses.

Chills being grown in off-show greenhouse

Over the weekend of the 17th of September there was the chilli and chocolate festival, which proved very popular with visitors. I blogged about this at the time, but the plants display was so popular we extended it for another weekend. The plants we grew were sold off, and we could have sold many more if we had had the growing space.

Baby gorilla Kukena

The two big events though were the birth of a new baby gorilla, a male called Kukena, very well timed for the week before the Wow! Gorillas campaign ended with the retrieval of the gorilla sculptures from round Bristol for a mass display on the lawn for one weekend before their being auctioned for charity. We raised £427,000 eventually, which went to the Bristol Wallace & Gromit appeal and Ape Action Africa, the ape rehabilitation and conservation charity we support in Cameroon (check out their website on the links section)

Earl of Wessex with Gorisambard

In October we had a visit from the new Earl of Wessex, who was presented at the end with a small copy of one of the gorilla sculptures we had made and decorated. This one was in the style of one of Bristol’s most famous sons, Isambard Kingdom Brunel. The original Gorisambard sculpture was the highest earner at the auction, fetching £23,000 for the charity funds.

Utila island iguanas

November started with baby Utila island Iguanas going on show. This is the first time we have bred this species, and the youngsters are doing well. When larger, they will go to various collections around Europe.

In November we also collected awards from BIAZA for the “best education project” and “best research project” for the year. The research project award has been given for an in-depth study on the nocturnal northern giant mouse lemur in Sahamalaza National Park, north-western Madagascar.

The education project award was given for the Zoo’s project called ‘All Creatures Great and Small’, which aimed to highlight the importance of biodiversity in celebration of the International Year of Biodiversity in 2010. Commendations were also awarded to Bristol Zoo in three categories – best field conservation project for its white-clawed crayfish project; best education project for its spider phobia courses, and best new zoo enclosure for the zoo’s amphibian breeding facility, the AmphiPod.

Solar panels on roof of veterinary building

In December solar panels were installed on the veterinary and service department building. Heating and lighting enclosures and visitor facilities is one of the zoos’ main running costs, and the panels should cover their costs within seven years. The panels were provided by a company based in Backwell (near Bristol) company Solarsense. The 184-panel 46.92kW solar photovoltaic (PV) system covers an area roughly the size of a tennis court.

Baby Goeldi's marmoset on parent

The last zoo news for 2011 was the birth of another baby Goeldi’s marmoset on 21st December. This is the second baby for the year (marmosets usually have litters around every 6 months) and the fourth for this breeding pair. In the New year I will be doing a series on the various primates we have here at Bristol, so watch this space for more details1

That’s about it for this years’ news from Bristol. I have one more post for 2011, and then I hope to see you again in 2012! Any comments or requests would, as always, be much appreciated.

(images from Bristol zoo website)

Review of 2011 - part 1

2011-12-23T09:20:00.000-08:00

To round up this years posts I will review the year at Bristol. This has been a major anniversary for us, as Bristol is the fifth oldest zoo in the world in continuous operation, and the oldest outside a capital city. From the start Bristol has pioneered many exhibit styles, and has majored in zoo education, research, and public service, so even if a visitor may see larger versions in other zoos, there is a good chance we were at least early adopters if not originators. For example, we were among the first to have a reversed photoperiod nocturnal house and walk-though aquarium tunnel (admittedly the latter is very small compared to more recent versions as it was created before modern acrylics came into use).

The year got off to a very good start with the birth of two lion cubs, Jasleen and Kaylara, to our pair of Asiatic lions. The cubs were born on Christmas Eve 201, but did not go on show for a few weeks until they had had their vaccinations (lions are susceptible to the same diseases as domestic cats). The cubs are now a year old and Jasleen (the male) is already beginning to get his mane. The cubs will probably stay at Bristol next year, before being moved to other collections to become parents in their turn.

In February the new Meerkat exhibit opened. This has proved very popular with visitors and with the Meerkats themselves, who have already produced several offspring. Also in February another tapir calf was born. This was the seventh calf our female Tamang has produced, and as she has produced more than enough offspring the male Denzil has now been moved to another collection. At present we have the adult female Tamang, her previous calf ( also a female) and young Roger on show.

In March, the zoo released its illustrated history (on sale at the zoo shop) with photos from bygone years at Bristol Zoo, including the famous TV presenter Johny Morris. We also put up photos of bygone years at the zoo, of which the most moving I find is a photo of injured troops on leave attending a concert on the lawn outside the main central buildings.

In April, plaques for a Walk of Fame were installed around the zoo. Produced by the famous Bristol Blue Glass works in the city, they commemorate famous Bristolians, from the notorious pirate Blackbeard to the late actor Cary Grant and the equally famous street artist Banksy.

In May, children from Fair Furlong Primary school came to plant their edible garden they have designed. Mike Crook, Bristol in Bloom Chairman, said: “From 75 entries Fair Furlong Primary was picked as the winner due to their interesting and well laid out design.” Eddie Mole, Head of Horticulture Gardens, said:“Their chosen produce consists of strawberries, courgettes, sunflowers and green beans plus a host of herbs which are easy to harvest as well as being aesthetically pleasing and great food for the animals.”

He added: “The competition is now in its third year and this time, our on-site catering team specified the plant list so that some of the produce can be used in the kitchens. The chef’s will be able to pick fresh, seasonal herbs to use in their daily cooking.”

Also in May, a baby sloth was born to our old female Light Cap in Twilight world. Unfortunately, he has had to be hand reared, but has done very well and is now on solid food like his parents. Perhaps inevitably, he has been named Sid.

The big event in June was a second set of twins for our Golden Lion Tamarins. After several unsuccessful years, we now have a nice family group of these beautiful monkeys – I will be doing a full post on them in 2012.

Also in June a male Red Panda finally arrived to join our solitary female Jasmina. After having to wait for a suitable match, Sir Ed arrived all the way from New Zealand and has settled in well in good time for the 2012 breeding season. With luck, we will have cubs next year.

Next time – the second half of 2012!

(Images from the Bristol Zoo website)