Beetles and Bugs 4: Fregate Beetle

Fregate Beetle

Growing to around 3cm at the most, compared to other beetles Polposipus herculeanus is not in fact especially large, but still an impressive member of the invertebrate fauna of Fregate island in the Seyechelles. A tenebrionid, it belongs to the same family as the more famous mealworm beetle, but unlike its relative it has a highly restricted range, being known today only from its namesake island.

News you may have missed

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.

Turtles and Tortoises 2: Not just on Galapagos

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.

In the pink

Greater Flamingos, India

The first aviary a visitor encounters at Bristol is the Camargue aviary opposite the entrance. Although it contains several species, the most instantly recognised are our flock of Greater Flamingos, Phoenicopterus roseus, one of two living species found in the Old World, along with the Lesser Flamingo, Phoeniconais minor. There are another four species found in the Americas, of which the only one found naturally in North America is the American Flamingo Phoenicopterus ruber. The American Flamingo was formerly classed as a subspecies of Greater Flamingo but has now been split into a separate species. There other three species live in the Andes at high altitudes, and comprise the Chilean, Andean, and Puna or James’ Flamingoes. Very few Andean or Puna flamingos are in animal collections, but some can be seen at the Wildfowl and Wetland Trust collection at Slimbridge.The vast majority of flamingos to be seen in zoos or wildfowl collections are Greater, Chilean, or American flamingos.

Pigeons of Bristol 9: And finally ...

Of all the endangered pigeons currently on show at Bristol, the species I am most proud we have is one of the rarest in the world, the Mauritius Pink Pigeon Nesoeanas mayeri. As the last surviving endemic pigeon of the Mascarenes (Mauritius and its related islands of Reunion and Rodrigues) it is of very considerable interest.


The exact taxonomic position of the Pink Pigeon has been unclear, and it has been placed in either the Old World pigeon genus Columba (along with the Rock Dove), or with the Collared Doves in Streptopelia. It seems to belong, with its much smaller relative the Madagascar Turtle Dove, in a separate clade, and is now placed in Nesoeanas. It appears that its ancestors colonised Mauritius from Madagascar some millions of years ago and evolved there, later colonising the younger island of Reunion. Reunion Pink Pigeons (now sadly extinct) have been placed in a separate subspecies, but were apparently very similar.

Pigeons of Bristol 4: Almost a Dodo

One of the most distinctive pigeons to be seen in the Forest of Birds here at Bristol is our group of Nicobar Pigeons, Caloenas nicobarica. This is a very distinctive bird, with a greenish iridescence (especially on adult birds) and long feathers on the neck which give rise to its alternative name of Maned Pigeon.

It is an island specialist, breeding in colonies on fairly small off shore islets and flying to larger islands to feed on the ground. The diet is seeds, fruit, and probably some invertebrates. It is fairly tolerant of human activities, and will visit fields to feed on grain. Unlike most pigeons, it has a single large stone in its gizzard which it uses to grind up food items.

Pigeons of Bristol 2: Pheasant?Pigeon?

One of the peculiarities of the bird life of the Australasian region is that it has, aside from two species of quail (which are migrants and therefore easily colonise new habitats), no native members of the Galliformes (the pheasants, quail and their allies). Instead, native groups such as the megapodes, button-quails, ratites, and even some songbirds like the Lyrebird, fill the ecological niche occupied by pheasants and grouse in other parts of the world. In the rain forests of New Guinea and the neighbouring islands these are joined by several species of pigeon, which have adopted a terrestrial lifestyle and a pheasant-like diet. In the last post I wrote about the Gallicolumba ground doves, this week I would like to introduce perhaps the most highly specialised of the surviving members of the pigeon family, the Pheasant Pigeon Otidiphaps nobilis.

Butterflies of Bristol 8: The Swallowtails

One of the most popular groups of butterflies to be seen in butterfly houses worldwide is the swallowtails (Papilionidae). Mostly medium sized to large butterflies (the Queen Alexandra’s Birdwing, Ornithoptera alexandrae is the largest of all butterflies, with a 30cm wingspan), they are also strong fliers and so make a good display. They are not usually true migrants, but they can stray long distances sometimes.

Swallowtails are grouped together by a distinctive feature of the larva, called the osmaterium. This is a forked structure that can be extended from the thorax of the larva and has a deterrent scent. The larva when disturbed will produce this and flail about to deter potential insect predators – although the frequency with which they are parasitized suggests this is not a very effective technique.

Land of the Dodo 16: Latest news

I will draw this series on the wildlife of Mauritius with some news from the Mauritian Wildlife Foundation, taken from their annual report and latest newsletter. Check out their website – and make a donation!

The MWF Solitude Endemic Nursery in Rodrigues produced 70,000 seedlings of 50 endemic species in 2008. These included 8 seedlings of Ramosmania rodriguesii, which was down to only a single remaining wild plant until cuttings were successfully propagated.

The Mauritius Fody has been downgraded from Critically Endangered to Endangered, as a result of the successful establishment of a population on Isle Aux Aigrettes. The mainland population now stands at 130 pairs, plus another 80 on isle Aux Aigrettes. Reintroduction to Round Island is planned for the near future.

Pink Pigeons exceeded 400 wild birds for the first time in February this year. Once the population reaches 600 the population can be downgraded from Endangered to Vulnerable status.

The recent nesting season for Echo Parakeets was very successful, with 112 young fledging; the population is estimated to exceed 400 birds.

There has appeared to be a decline in the population of Mauritius Kestrel, with a reduction in the smaller population on the east coast. The total population is around 600 birds.

Rodrigues Fody was reduced to only 6 pairs in 1968, but by 2007 had increased to 3,000 individuals,

Rodrigues Warbler was reduced to 17 individuals by 1982, but had increased to 1,000 by 2007.

After numerous nesting attempts, the first Mauritius Olive White-Eye from the introduced population on isle Aux Aigrettes fledged in October 2008.



















The translocation of Telfair’s skinks to Isle Aux Aigrettes has proved a success. Not only has the skink bred outside of Round Island for the first time in 150 years, but several introduced pests such as House Shrews, Indian Wolf Snakes and FRICAN Land Snails have declined or died out altogether.

Aldabra Giant Tortoises and Radiated Tortoises were released on Round Island in 2007 as part of a PhD project to determine whether they can replace the extinct native tortoises.

Having recovered from a low of 100 individuals in the 1970’s, the population of Rodrigues Fruit bat now stands at over 5,000.

Finally, a captive breeding programme has been established on Jersey in the DWCT Herpetology department, with the aim of producing enough Lesser Night Geckos, Nactus coindemerensis, for an introduction to Ile Marianne.

PS - Reminder

The research colloquium at Bristol Zoo Education department is this Wednesday 7th October at 5.30. The subject is an investigation of Vitamin D levels in tropical primates at Bristol, and will hopefully provide useful information on the husbandry of these animals at high latitudes - is their enough sunlight for exposure outside to meet their requirements? The speaker is Rowena Killick (RCVS Trust Senior Clinical Training Scholar in Zoo Animal Medicine).

Land of the Dodo 15:Seabirds

When the Mascarenes were first discovered, the main islands did not have an extensive diversity of breeding seabirds, but offshore islets had some colonies of many species. These were often raided for eggs and young birds for food, and the burrow-nesting petrels are highly vulnerable to rats, which together have resulted in local extinctions of some species. A few of these have re-colonised naturally, but some others have been lost and world populations are now so low that it is unlikely that new colonies will be formed on the islands without outside help.

Currently only visitors to the islands are Greater and Lesser Frigate birds Fregatta sp., of which at least one species was reported as breeding when the islands were first discovered, Great Crested Terns Thallasseus bergii, and various Indian ocean gulls and terns, plus some Palaearctic migrant waders making stopovers, such as Ruddy Turnstones. Pelicans were reported offshore in 1598, probably Pink-backed Pelicans Pelecanus rufescens (which we have here at Bristol), which formerly bred in the Amirantes atolls north of Madagascar.

Three species of boobies formerly bred in the Mascarenes. One species just holds on, the Masked Booby Sula dactylatra, which breeds on Serpent Island. Red-footed Boobies Sula sula bred on Rodrigues until the 1870’s. The most important species however was the tree-nesting Abbott’s Booby, Papasula abottii (shown at top) which was probably both persecuted for food and also lost nesting habitat to deforestation. Abbott’s booby was ever only found on four stations, but today only a single breeding colony on Christmas Island remains, and this is too far away and too small to provide potential recolonists.

Several species of terns are found in the Mascarenes, some of which have recolonised after becoming locally extinct. The commonest are the Brown and Lesser Noddy, with Rodrigues also having colonies of Roseate Tern, Sooty, and Fairy Terns.






Two species of Tropicbird can be found on the islands, the inshore White-tailed Tropicbird and the more oceanic Red-Tailed Tropicbird, with the latter being the more common. They are increasing under protection and also benefiting from the recovery of the vegetation on Round Island and other seabird islets now that goats and rabbits have been removed.



The most important of the seabirds on the islands however are the various species of petrels. Petrels mostly breed in burrows, mostly only coming ashore after dark, so they are very hard to study. The Reunion Black Petrel Pseudobulweria aterrima appears to be a very rare breeder, and the breeding site was only recently located. Only once reported prior to the 19th century, it was probably always rare. It is part of a group of species which are otherwise found in the Pacific except for an extinct species from St Helena in the Atlantic. By contrast, the Wedge-Tailed and Tropical Shearwaters Puffinus sp. are both still fairly common, although Tropical Shearwater is extinct on Mauritius.

With the recovery of the vegetation in recent years, the situation on Round Island has become complex. Originally only a single species, the Round Island Petrel, believed to be a local form of the Trinidade Petrel Pterodroma arminjoniana, was known, but in recent years two other species have colonised, Bulwer’s Petrel Bulweria bulwerii, and Kermadec Petrel Pterodroma neglecta. The Kermadec Petrels sometimes hybridise with the Round Island Petrels, and it appears that a hybrid swarm of mixed parentage is forming. Both the Kermadec and Bulwers’ petrels appear to be new colonists of the western Indian Ocean.

This situation however is not unknown amongst seabirds, and sometimes islands are colonised from considerable distances away. One such colonisation probably resulted in the Reunion nesting Barau’s Petrel Pterodroma baraui. This appears to have been derived, however unlikely this seems, from the Hawaiian Petrel. Even more unlikely, these colonists seem to have brought with them on their feathers the seeds of a specialised shrub, Acacia koa, which itself has evolved into the Reunion endemic species Acacia heterophylla. On both Hawaii and Reunion the petrels and the acacia are closely associated, living at high altitudes on the slopes of the volcano.

Until recently, seabird conservation in the Mascarenes has involved only protection from persecution and habitat restoration, but attempts are just starting on direct reintroduction. One might wonder how this can be done, since seabirds all leave the breeding sites after fledging, usually for several years, but the secret is to take advantage of the tendency of fledglings to imprint on their birthplace, which in the case of petrels is whatever they see when first leaving the darkness of the burrow. In addition, many seabirds do not have post-fledging care – the chick, which at the point of fledging has a large amount of fat stored, makes its own way to the sea and teaches itself to fish. Currently being attempted are translocations of such fledglings to Isle Aux Aigrettes, with the hope that such birds will return to nest in later years. If these prove successful, possibly even Abbott’s Booby may be reintroduced at some time.

Images from Wikipedia from top:

Abotts Booby
Brown Noddy
White-Tailed Tropicbird
Wedge-Tailed Shearwater

Land of the Dodo 14: The other land birds

Aside from the land birds mentioned in previous posts, a further eight species of land birds are known from the Mascarenes, of which one is extinct. This was the Hoopoe Starling Fregilupus various, which became extinct in the mid-19th century. The cause of the extinction is unclear – it was apparently a generalist feeder and suitable habitat still appears to be available. Possibly deforestation and removal of trees with holes for nesting was the cause, but introduced disease must be a prime candidate. Island animals, because of their inevitably small populations, do not have as large a reservoir of disease resistance genes as continental populations, so they are permanently vulnerable to new diseases.

One of the only two surviving land birds on Rodrigues is the Rodrigues Warbler, Acrocephalus rodericanus. This is closely related to the Seychelles warbler, and belongs to a very successful genus of small insectivorous birds which combined have a gigantic range – at least 38 species are known of which two, the Reed and Sedge warblers, are common British birds and several others are know as either scarce breeding birds or regular vagrants to the UK. The Rodrigues warbler has had a good deal of protection and the population is currently at several hundred birds

Found only on Reunion is the Reunion Stonechat Saxicola tectes (shown below). Stonechats are another widespread group of birds, which have been recently split into several species. The Reunion stonechat is a fairly common species at higher elevations, where it frequents the cloud forest and giant heather heath land. It probably evolved from the Madagascar Stonechat S.axillaris, but stonechats are long-distance migrants so the founders could have come from further afield.























Found on Mauritius and Reunion are two species of Cuckoo-Shrikes (Coracina typica and C. newtoni). These feed in the canopy on large insects and lizards. Their origin is uncertain, but they resemble Cuckoo-Shrikes found in Australasia. (shown here, Black-faced Cuckoo-Shrike C.novaehollandiae)

Finally, there are three species shared between Mauritius and Reunion.

The Mascarene Swallow Phedina borbonica is also found on Madagascar, where it is partly migratory, so its presence on Mauritius is not hard to explain. The population on Mauritius at least is small, in the low hundreds at best.

The Mascarene Paradise Flycatcher Terpsiphone borbonnensis feeds low in the under story on small insects. It is very rare, but surprisingly on Mauritius it seems to be breeding successfully in forestry plantations.













Finally, least studied of all the remaining land birds is the Mascarene Cave Swiftlet Aerodramus francisus. Possibly derived from the Indian Cave Swiftlet, it suffers from the tendency of Mauritians to regard lava tunnels it requires for nesting as convenient sites for dumping rubbish. (All images from Wikipedia)

Land of the Dodo 13: Bulbuls

Scattered from Asia to Madagascar, the Black Bulbuls of the genus Hypsipetes comprise nine surviving species, of which two survive in the Mascarenes, on reunion and Mauritius. An additional species, not yet formally named, is known from fossil remains on Rodrigues and died out either before or shortly after first contact – there are no surviving accounts of it known.

Bulbuls are medium sized, largely fruit-eating birds, supplementing their diet with insects, especially when breeding. The nest is an open cup, built in a bush or tree, and in general they can be thought of as the Asian equivalent of common European and American thrushes.

The Hypsipetes bulbuls of the Mascarenes seem to have originated from Asia, initially via the Seychelles. From the DNA evidence it appears that the Mascarene birds then went on to colonise Madagascar, which in turn then spread out again to the Comoros, where two species now occur – one originating from the wave that colonised the Mascarenes, and a second derived from the Madagascar Black Bulbul Hypsipetes madagascariensis.

The Reunion Bulbul H.borbonicus (called a Merle there) is still common, but the birds are more easily heard than seen. I was unable to locate any decent photos of either of the Mascarene species, so the picture at the head of this post is the common Indian Black Bulbul Hypsipetes leucocephalus.

Unfortunately the Mauritius Merle H.olivaceus is in a far worse state. The current population is under 300 pairs, which is far too low to be secure, but at least at present the population appears stable. The probable reason for its decline is habitat destruction, and it is hoped that the restoration projects currently under way will help to foster an increase.

Unfortunately, one obstacle to this is an introduced species, the Red-whiskered bulbul Pycnonotus jocosus. This is a fairly common cage bird, and has been introduced to both Mauritius and (more recently), Reunion. This has the potential to compete with the Merles, especially in human-modified habitats, and possibly act as a reservoir of disease. In addition, introduced predators such as rats may predate on nests.

Aside from habitat restoration, there is currently no specific conservation interventions aimed at benefiting the Mauritius bulbul. Some related species are however kept, and sometimes bred, in a few zoos, which provides a baseline of avicultural knowledge if a captive breeding programme for any of the Mascarene species is required, or possibly a re-introduction of a related species to Rodrigues.

Picture at top: Black Bulbul from Wikipedia
Picture at bottom: Red-Whiskered Bulbul from Wikipedia

Land of the Dodo 12: The White-eyes

Scattered on most of the islands of the Indian Ocean, Australasia, and the pacific, as well as the mainland of Africa, and Asia is a huge group of small passerine birds, the White-Eyes, Zosterops. There are currently over a hundred species, with more being described each year. One would think that such diversity is a sign of a long history, but in fact the genus seems to have originated only a few million years ago. This makes Zosterops one of the fastest evolving vertebrate groups, about as fast as the well known cichlids of the African Rift Valley.

The reason for this rapid expansion is not altogether clear – separate species have evolved even on islands separated by only a few kilometres. This would suggest a species that does not move far, which is contradicted by the rapid spread of the genus as a whole. It appears that part of the reason is the short generation time and the tendency of the species to move around in flocks, which means that either large numbers of colonists arrive at a new location, or none – there is no steady “drip” of genes travelling from the source to the founder population.

White-eyes are fairly generalist small passerines, behaving in many ways like the leaf warblers Phylloscopus found across temperate Asia. The plumage is usually yellow-green, with a distinctive white eye-ring, which is where the name comes from.The main diet is insects, supplemented by fruits and nectar. The nest is an open cup made of grasses and moss, and the clutch is usually 2- 4 eggs.

There are three or four species surviving on the Mascarenes, living on Mauritius and Reunion. None are known from Rodrigues, but this may mean that they died out before being recorded. It appears that they are closest to the Asian White-eyes, although other Indian ocean islands have been colonised from Africa.
The Grey White-Eye is found on both Reunion and Mauritius. Depending on the taxonomist, the two islands are either home to a species each (Zosterops borbonicus and Zosterops mauritianus), or they are united as subspecies of the Reunion Grey White-eye shown here. Both forms are fairly distinctive, having lost the yellow in their plumage and also the white eye-ring, but in their behaviour they are typical white eyes. Both species are still common, probably because they are adapted to disturbed habitats such as man-made clearings.

Far more distinctive, and in more trouble, are the two species of Olive White-Eye. The Reunion species, Z.olivaceus, is allegedly still common, at least at higher elevations, but the Mauritius Olive White Eye Z.chloronothus (shown at top) is critically endangered, and is restricted to only 25 square kilometres on the mainland, with perhaps only 100 pairs. With a species with such a short lifespan this means that only 2 bad breeding seasons could result in its extinction, so strenuous efforts are being made to enable its survival, in the form of regeneration of native forest and captive breeding attempts. Some have been released on isle Aux Aigrettes, but until recently there had been no successful nesting. However, in October 2008 for the first time 2 young were fledged on the island.

The problem the Olive White-Eyes have is that they have become specialists. Unlike their adaptable ancestors, they have become specialist nectivores, feeding mainly on the nectar of native plants. With the widespread habitat destruction this has resulted in a loss of their food source, with inevitable results. Experiments are being made with supplemental feeding – as many in America who feed hummingbirds know, nectar feeding birds will often take to artificial feeding stations. The main problem is that nectar feeders tend to be territorial around food sources, so any feeding stations have to be widely scattered, which takes a lot of upkeep in difficult terrain.

Images- Mauritius Olive white-eye from Durrell Wildlife Conservation Trust
Reunion Grey White-eye from Wikipedia

The endangered pest

Recently added to the Wallace aviary birds here at Bristol is a small flock of a very pretty small songbird, the Java Sparrow. They are kept because they pose an interesting example of how species can be at the same time threatened in one area and a potential pest in another.

Originating, it is believed, in Java and Bali in Indonesia, their popularity as cage birds means that they have been taken throughout neighbouring islands and more recently all over the world – there is for example a well established feral population in Hawaii. They are also popular in aviculture – I have a few in my aviary in my back garden right now – as they are extremely easy to care for and always present an incredibly smart appearance (bar a few weeks a year during the moult).

Javas (Also know as Rice Birds), have the scientific name Padda oryzivora. Oryzivora means “Rice Eater”, which will give a clue as to why they were persecuted in their homeland. They are extremely prolific, and as a result were major crop pests.

Javas are an estrildid finch, in fact the largest living species, and as such belong to a group of small, mostly grass-seed eating birds, which include several other popular cage birds such as the Zebra finch, Bengalese, and Gouldian finch. The basic ecology of this group of birds is to subsist as adults mainly on ripe and ripening grass seeds, supplementing with some other vegetable matter, and feeding their young on insects and unripe seeds. They often have large broods of young and in the right circumstances can increase their numbers very quickly. The downside of this is that they tend to be short lived in the wild, so adverse situations can result in equally rapid declines. Their main natural predators are probably snakes and small mammals when nesting, and birds of prey once fledged.

In recent years the Java sparrow has faced such a decline – in fact it is classed as Vulnerable on the IUCN Red List – and a recent survey could only locate 109 individuals at 17 sites. In addition, persecution in those areas where it has been introduced has resulted in declines amongst feral populations. The most probable cause is persecution by farmers, capture for the cage bird trade (although this is completely unnecessary as they breed well in captivity), and possible competition form the Tree Sparrow Passer montanus, which is the common city sparrow in Asia.

Javas were at one time introduced to Mauritius, undoubtedly as cage birds, and were breeding in the wild by the 1750’s. However, later persecution and probably competition with House Sparrows resulted in their extinction in the early 20th century.

Closely related to the Java sparrow is the Timor sparrow Padda fuscata from, as you might guess, the island of Timor. Timor sparrows are much less common in aviculture, although also threatened, but are dark brown where a Java is grey. It is currently more common in the wild than the Java, although it faces the same threats and is consequently classed as Near Threatened by the IUCN.
The conclusion of all this is that even the commonest species can be much more threatened than it looks, especially if it relies on groups for survival. Most people will be aware of the catastrophic collapse and extinction of the Passenger Pigeon – it is important therefore to build up as wide a knowledge of all species, both in the wild and in captivity, as it is possible to arrange.

If you wish to learn more about these beautiful little birds, look at the Java Finch Society website www.javafinch.com

Land of the Dodo 11: Weaving a spell

Scattered through Madagascar and the nearby islands of the Indian Ocean is a group of at least 10 species of weaver birds, the fodies of the genus Foudia. Unlike the colonial weavers of mainland Africa, they behave far more like most passerines, nesting in paid by themselves.

Primarily forest birds, one species, the Madagascar or Cardinal Fody, has adapted to open grassland and is often found around farmhouses. As a result of people liking their colours, the Madagascar fody has been taken to many other islands, including St Helena in the Atlantic.

At first contact, there were three fodies in the Mascarenes, one for each of the islands, but today only the Rodrigues fody F.flavicans (left) and the Mauritius fody F.rubra (top)survive. Even these only barely managed to hang on, with the Rodrigues at one time down to perhaps 6 pairs before conservation measures helped its recovery (it currently stands at 900-1000 birds). The Mauritius fody is in far worse shape, and there are intensive conservation measures being undertaken to help it to survive.

Fodies are most closely related to the Orange Bishop, Euplectes, an African weaver bird that like the fodies nests independently. One might think that the birds on the islands originated from Madagascar, but analysis of their DNA shows that the sequence runs from the Seychelles, then to Rodrigues, then Mauritius, and finally Reunion, Madagascar, and the Comoros islands. Originally a rainforest bird, one of the Madagascan species adapted to grassland, later became a bird of farmland, and has now been introduced to all three islands, which on Mauritius and Rodrigues it shares with its close relatives.

The main cause of the decline of the fodies was probably introduced rats, which readily predate fody nests. It is one of the ironies of conservation that the only reason the Mauritius fody survived was because of aplantation of introduced Cryptomeria trees, which do not provide food for rats or monkeys and consequently enabled at least some nests to escape.

Intensive help for the fody, and indeed the other passerines of Mauritius, only started in 2002. Fodies have proved reasonable straightforward to breed in captivity, and techniques of hand rearing have been devised to enable chicks from wild nests to be reared. This is of course a very labor intensive process, and readers may be interested in the rearing diet. This comprised the following:
Bee larvae (throughout the rearing period)
Crickets (first guts, then abdomens)
Waxworms (older chicks only)
Mice (first internal organs, then cut up as the chicks grew)
Papaya
In addition, chicks received Nutrobal, Avipro, and Nekton as vitamin and mineral supplements

Initially chicks were fed hourly between 05:00 and 21:00, with the intervals between feeds increasing to 2 hours by the end of the rearing period, with chicks fledging at 18 days. Hand reared chicks were kept in a brooder at 36 degrees at first, gradually reducing as they fledged to the ambient air temperature of 26 degrees.
These hand reared chicks were released on isle aux Aigrettes, and the attempt has proved a great success. Fodies are now breeding on the island, with over 150 birds. One problem is the introduced Madagascar Fody (below), which could potentially hybridise. It appears however that the difference in preferred habitat and song make it unlikely for the two species to interbreed, but the situation is being closely monitored.

Acknowledgements:
Mauritius Fody image from Durrell Wildlife
Rodrigues Fody from ARKive
Madagascar Fody from Wikipedia

Land of the Dodo 10: The other pigeons

Aside from the Dodo and the Rodrigues Solitaire, there were at least four and possibly five endemic species of pigeon inhabiting the Mascarenes, of which only one, the Mauritius Pink Pigeon (shown at top of post), barely survives. In addition the Madagascar Turtle Dove was present and either survived or was reintroduced from Madagascar.



The main causes of the extinctions were rats, monkeys, and most seriously hunting. Judging from the behaviour of the surviving Pink Pigeons, the birds had practically no anti-predator responses and would not learn caution, or at least were wiped out too quickly to acquire any.

The pigeons can be divided into two genera, the first, Nesoenas with affinities with Africa included the Madagascar Turtle Dove and the Pink Pigeons (two species on Mauritius and Reunion, of which the Mauritius form survives), the second, Alectroenas (Blue Pigeons), with Asian affinities and species on Mauritius, Rodrigues, and probably Reunion. Why the Blue pigeons died out is not altogether clear – Alectroenas pigeons are still widespread on the Comoros Islands and the Seychelles despite human presence. Possibly habitat destruction overwhelmed them too quickly to adapt. The loss of the Mauritius Blue Pigeon, known as the Pigeon Hollandais because its colours resembled the Dutch flag, is a great loss to the islands – a picture of the Seychelles Blue pigeon is shown here:

As well as losses, several species of pigeon have been introduced to the islands – the ubiquitous feral pigeon of course, as well as Spotted Dove and Laughing Dove (both from Africa) and the Zebra Dove of South East Asia. These do not seem to compete directly with Pink Pigeons but they are potential reservoirs of disease.

Today the Pink Pigeon is the subject of intensive effort to rehabilitate the species. Bristol Zoo has bred them in the past, but it has proven extremely difficult to breed outside of Mauritius, and there are currently 49 in European zoos (including four at Bristol), with another 43 in the USA. In the islands breeding and protection of wild nests has boosted the population, and as of December 2008 the wild population stood at 393 birds. This sounds very small, but is a considerable improvement on the situation in 1986, when only 12 birds could be found at the only site they survived in.

Aside from predators, the main threat appears to be habitat degradation. Pink Pigeons are adapted to feed both on the ground at at the end of long branches, and deforestation and introduced plants do not provide the correct food. Fortunately they take readily to bird tables, so supplemental feeding is easy to provide. Indeed, there was an attempt to release birds in one of the botanic gardens on Mauritus. The birds survived, and even bred, but were wiped out by small boys with catapults, for who they made easy targets.

Despite the setback, new populations are being created. Most recently a new sub-population using translocated birds was established at the lower Black River Gorges, and the first fledgling left the nest in September 2008.

As the Reunion Pink Pigeon was closely related to the Mauritius form, which was its ancestor, it might be possible in the future to reintroduce them to Reunion. Unfortunately, at this point politics intervenes. Whereas Mauritius, with Rodrigues, was a British colony and is now independent, Reunion is a French Overseas Department, so there is less connection between conservation on Mauritius and Reunion than there should be.

Land of the Dodo 9: Rails

One of the most successful groups of birds to colonise oceanic islands are the Rails, the group of birds which includes coots, moorhens, and gallinules. Invariably terrestrial, and usually secretive, they do not look like good long distance flyers, but they are surprisingly good at finding and settling down on remote atolls.
Unfortunately, having done so, they frequently (and often rapidly) tend to become flightless, which means that extinct rails are a major feature of the history of human colonisation of the worlds’ islands.

The Mascarenes had at least six extinct species, which roamed the thickets and grasslands of the islands feeding on invertebrates, especially snails (snail shells show the distinct signs of being broken open by powerful beaks), crabs, and in the case of the largest species possibly even baby tortoises. This did not help them against rats, cats, and mongooses – all were gone by 1720 at the latest.

The picture at the top of this post is of a Purple Swamp hen, Porphyrio, which is the probable ancestor of a bird, the "oiseau bleu" formerly found in the hills of Reunion. Unfortunately no bones have yet been found, but the description fits very well and this species is very widespread in Africa and southern Europe (it has also been introduced to the Everglades). Birds of this type also colonised New Zealand, evolving into the highly endangered flightless Takahe.

The most specialised (and probably oldest endemic species) was the Red Hen, Aphanapteryx. This has caused some confusion, as after the extinction of the Dodo the name was transferred to the Red Hen, and consequently people believed the Dodo survived longer than was in fact the case. The Red Hen had silky feathers, similar to a Kiwi, although in no way related.

Three endemic species of Wood Rail, Dryolimnas, inhabited the three main islands. These were local forms of the Madagascan White-Throated Rail, which has a flightless race still inhabiting Aldabra.

The Mascarene Coot, Fulica newtoni, was close to the Crested Coot of Africa and Spain. The reason for its extinction is unclear – Coots are usually well able to take care of themselves. However the available habitat for water birds is limited on the islands, so habitat destruction by early colonists was probably a major factor.

Finally, a new arrival reached the islands in the late 18th Century, probably from Africa. Common Moorhens, Gallinula, the same species that is found in Europe and the USA, have now become widespread in the islands. There have been reports in the past of White-throated Rails reaching the islands from Madagascar, so it is still possible that new rails may yet colonise the islands.

Land of the Dodo 9: Waterbirds

At first contact, there were many species of water bird have colonised the Mascarenes, of which seven are extinct and of the survivors, all are wide-ranging species which still survive in other parts of the world, and may yet recolonize naturally.

Of the ducks and geese, the Mascarene Teal Anas theodori survived on the islands until approximately 1700. This was closely related to the Madagascan Berniers Teal, itself now critically endangered and subject to a captive breeding programme. (Image of captive bird at Slimbridge)


Mauritius and Reunion each had an endemic species of sheldgoose, Alopochen, close to the Egyptian Goose which still is widespread in Africa, and for which there is a small feral population in the UK. Both species were extinct by 1700, probably as a result of rats.

Probably also exterminated by rats were the three species of Night Heron, Nycticorax, although habitat destruction may also have played a part. The Night Herons could fly, but were reluctant to do so, and probably preyed heavily on land crabs and baby tortoises. The destruction of the crabs by rats and House Shrews would have eliminated much of their food supply.

Reunion held a species of ibis, Threskiornis solitarius, which was close to the African Sacred Ibis. Like the night herons, it was reluctant to fly and probably became extinct (by 1720) for similar reasons.

The small population of Greater Flamingos on the islands was probably eliminated by hunting. Even before human contact, most of the birds would probably have been non breeders from Madagascar or mainland Africa.

The reason for the extinction of the widespread and successful Dimorphic Egret is unclear – probably introduced mongooses were responsible. The available habitat for water birds is limited on the islands, and colonies were probably restricted to only a few sites. The Reed Cormorant probably died out for similar reasons on the islands, despite being widespread in Africa.
Finally, at least one widespread species has colonised naturally since the arrival of humans on the island. The small Striated Heron (close to the American Green Heron) probably colonised in the early 19th Century and is now present on all the islands.

Land of the Dodo 8: Birds of Prey

Prior to human contact the Mascarenes were home to six species of birds of prey, active by both day and night. Today only two species survive, the Reunion Harrier and the Mauritius Kestrel. The Mauritius Kestrel is particularly important as it is one of the best examples of what a coordinated approach to conservation can do with a highly endangered species.

Unfortunately extinct are all three of the three endemic species of owl, all placed in the genus Mascarenotus. Apparently most closely related to the widespread genus Otus, the Scops Owls (one of which reached the UK from Europe two years ago and actually held territory for a while), the Mascarene owls were larger, and had the long legs without feathers which usually indicate a specialist lizard feeder. Their distinctiveness is such that they may have originally evolved on the islands preceding the emergence of Mauritius. They were all gone by 1830 at the earliest. Shown here is a Madagascar Scops owl.

The image here is of a Reunion Harrier, Circus maillardi. These have a world population of fewer than 400 individuals and a low reproductive rate, although they are slowly increasing under protection. Unlike most harriers, they will hunt over woodland. Their original diet was probably birds, but today perhaps 50% of their diet comprises introduced mammals, including the ubiquitous tenrecs. Although now confined to Reunion, it formerly occurred on Mauritius and could potentially be reintroduced there at some point – there have been several successful reintroductions of birds of prey around the world (including the extremely successful reintroduction programmes for White-tailed Sea Eagle and Red Kite here in the UK) although as far as I am aware there have been no introductions of harriers so far.

Finally, we have two species of kestrel. The Reunion Dubois’ Kestrel is now extinct, but was similar in structure to the European Common kestrel Falco tinnunculus. Surviving reasonably well (and shown below) is the Mauritius kestrel, Falco punctatus, but it was a very close run with extinction.

The initial problem was deforestation, which by 1900 had reduced the population to about 200 pairs. The final disaster was DDT spraying for malaria, which eliminated all birds outside one small area, the Black River Gorges where it was not used. In 1974 the total wild population known was four birds, of which only one was a breeding female.

At this point an extensive support plan was put into effect. Wild eggs were harvested to create a captive population, and nestlings were supplementary fed. Removing eggs from an incomplete clutch of eggs often results in birds laying additional eggs, so boosting productivity. Nest sites were monitored and protected against raids by monkeys or rats. By 1994 nearly 350 had been released.

Today the Mauritius kestrel has a wild population of 800 – 1000 individuals, and has been downgraded from Critically Endangered to Vulnerable status.

The ongoing threats are introduced predators such as monkeys, and potentially introduced avian diseases. The small population that the birds were reduced to means that the birds have lost a lot of genetic diversity and this makes the population more vulnerable to new diseases.

Land of the Dodo 7:Going Batty

When first colonised, the Mascarenes were home to three species of fruit bat and at least three – possibly more – species of microbat. One of the fruit bats, and at least one of the microbats, is now extinct. The other microbats are doing well, but the two surviving fruit bats are both much reduced in numbers and range.

Traditionally, bats have been divided into two groups, the fruit bats or megabats, confined to the Old World, and the microbats, which have a worldwide distribution. The main reason for this is that the old world fruit bats do not use echolocation in the same way as microbats do, and it was believed that this may even have been because they were not closely related to microbats, possible having developed flight independently. It now appears that this distinction is inaccurate, and the most basic division in the bats is between a group containing the megabats, horseshoe bats and their relatives, and all other bats. Interestingly, horseshoe bats wrap their wings around themselves when at rest as do megabats, whereas in other species the wings usually are held at the sides. In the Americas, many species of microbats also eat fruit.

Fruit bats are important pollinators (despite their name, they are fond of nectar) and also dispersers of seeds. A lack of these is a major cause of delays in regeneration of cleared tropical forests world wide, and it has been shown that encouraging fruit bat population helps considerable in restoration of forest cover.

Unfortunately, fruit bats and people have very similar tastes, and as a result in many parts of their range they are persecuted as crop pests. Recently the Mauritius government authorised a cull of one of the surviving species, the Mauritius Fruit bat, despite the estimated population being only 20,000. This has now been halted pending further investigation of the status of the species.

On Rodrigues, there were at least two species, the Mauritius Fruit Bat and the Golden Bat (Photo of Golden Bat at head of this post – image from Lubee Bat Conservancy). Only the Golden Bat survives, although it formerly bred on Mauritius as well. It is seriously endangered, with a world population estimated at 5,500, which is still a great improvement on the case in the 1970’s, when it was down to 150.

Sadly extinct is the smallest and most widespread of the three fruit bats of the Mascarenes, the Rougette. Possibly most closely related to the surviving Seychelles Fruit bat, it lived in large groups in hollow trees. This is unusual for fruit bats – most species roost on open branches of tall trees. It was this habit that may have caused its extinction – they were easy to capture both by people and introduced monkeys, and deforestation would have removed roost sites.

The insectivorous microbats on the islands seem to have survived better, with the exception of one species on Reunion, the Pale House bat. This may have gone extinct for the same reason as the Rougette – it seemed to have had similar habitat preferences. Most of them have close relatives in Madagascar, Africa or India. People tend not to think of bats as migrants, but many can travel long distances over water – there is a record of a Little Red Flying Fox which managed to reach New Zealand from Australia.

There are several institutions which hold Golden Bats. Bristol formerly held a non-breeding group, but these have gone to other collections. They are often quite active by day, especially in the afternoon. Bristol currently holds a breeding group of Livingstone’s Fruit Bat, which I will blog about another time.