Friday, 27 January 2012

New World Primates 4: Brown Spider Monkey

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.

Saturday, 21 January 2012

New World Primates 3: Silvery Brown Tamarin

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.

Saturday, 14 January 2012

New World Primates 2: Lion Tamarins

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.

Saturday, 7 January 2012

New World Primates 1: Goeldi's marmoset

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.