Saturday, 27 March 2010

Pigeons of Bristol 5: Count the Ducula

Throughout the rainforests of South East Asia, Australasia, and the Pacific anywhere there is a reasonable expanse of rainforest you are likely to find in the trees a large pigeon, commonly called an Imperial-Pigeon, of the genus Ducula. Currently at Bristol we have two species, the Chestnut-naped Imperial-Pigeon D.aenea shown below and the Pied Imperial-Pigeon D.bicolor at the head of this post.

These are the most likely to be seen in any zoo which holds Imperial-Pigeons, but the ISIS listing currently shows 12 other species in various zoos, mostly only a few individuals at a single collection, although the Nutmeg or Torres Strait Pigeon, with 154 worldwide, is also to be seen and aside from the two species at Bristol probably the only one with a viable captive population. In the wild however Imperial-Pigeons are very diverse, with over 100 different species or subspecies described.

Sunday, 21 March 2010

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.

Monday, 15 March 2010

Pigeons of Bristol 3: Crowned Pigeons

In the Forest of Birds here at Bristol we have a pair of the most spectacular (and since the demise of the Dodo, largest) of all the pigeon family, Victoria Crowned Pigeons Goura victoriae. One of three species of Goura that may be seen in zoos worldwide, Crowned Pigeons originate from New Guinea. All three species overlap in parts of their ranges, and hybridize both in the wild and in captivity, so whether they should be classed as subspecies or full species rather depends on the taxonomist concerned. The three forms are however quite distinctive in appearance, so are probably best treated as separate species, and are managed separately in studbooks. The other two species are the Blue or Western Crowned Pigeon G. cristata, which comes from western New Guinea and related islands, and Scheepmakers Crowned Pigeon G. scheepmakeri, from along the south coast of New Guinea. The Victoria Crowned Pigeon mirrors the distribution of Scheepmakers pigeon in northern New Guinea.

Monday, 8 March 2010

March Research Colloquium: Lemurs on the Rocks

This months research colloquium was by Professor Lisa Gould of the Anthropology Department, University of Victoria, Canada. professor Gould has been studying Ring_Tail lemurs for longer than almost anyone else in the world, and gave a very interesting talk on one of the world's most instantly recognizable primates.

With its distinctive appearance and readiness to breed in captivity, the Ring-Tailed lemur, Lemur catta (so named because of its cat-like call) is the most instantly recognizable and well-known of Madagascar’s native primates. Just because it is well known in zoos however, is no measure of the knowledge of the species in the wild, and this month’s research colloquium had some intriguing, and even slightly hopeful, information.

The Ring-Tailed lemur is plainly a very atypical lemur in many respects. Whereas almost all lemurs are arboreal forest animals, Ring-tails are semi-terrestrial, in some habitats spending as much as 70% of their time on the ground. They are also very adaptable in the habitat they can use, from gallery forest along rivers to rocky slopes, abandoned farmland, and basically anywhere they can find food and water. They are also quite variable in their behaviour, as studies at Anja reserve by our speaker have shown.