Sunday, 13 July 2014

New Arrivals: Visayan Warty Pig

Visayan Warty Pig
Moving on from hornbills, it is perhaps appropriate that the zoo has just added to the collection a new species that shares the range and habitat of the Visayan Tarictic Hornbill, The Visayan Warty Pig Sus cebifrons negrinus. This is sadly classed as Critically Endangered, with it now being extinct over perhaps as 98% of its former range, and is now found only on two islands of the Visayan group, Panay and Negros. The captive populations originating from the two islands are managed separately, with Panay pigs in US zoos and Negros pigs in Europe, where Rotterdam Zoo coordinates the programme. This is because although they are currently classed as the same subspecies, the two island populations have been isolated at least since sea levels rose at the end of the last glaciation, and may perhaps be better classed as separate subspecies.

In their behaviour, all the various species of Sus are very similar, and the Visayan Warty Pig is no exception. They are highly omnivorous, which means they are quite happy to raid crops (which of course means that local farmers will hunt them where possible). They are also highly social, with a sounder usually consisting of a single adult boar, several sows, plus a varying number of juveniles. They tend to feed at night, lying up during the day under cover, or seeking out mud wallows to keep cool, as their relatives the European Wild Boar Sus scrofa does.

The islands and mainland of south east Asia seem to have been the centre of origin for the various species of Sus, with the Visayan Warty Pig the oldest surviving branch. They seem to have diverged comparatively recently, perhaps around 5 mya, when a single species, the ancestor of the Eurasian Wild Boar spread westwards and northwards away from tropical rain forest across the Old World. This was of course the ancestor of domestic pig breeds, and it was domesticated at least twice, in China and probably central Europe.  Unfortunately, all the species are still so closely related that they can interbreed to produce fertile hybrids, and genetic pollution from feral domestic pigs is a major threat to the rare island species especially.

Physically, Visayan Warty Pigs are extremely odd looking animals, especially the males. In body form they are standard, rather small, pigs, but their distinctive feature is their mane. This takes the form of a crest of hair along the back, with a topknot of longer hair between the ears. In the breeding season adult males develop a much longer mane which gives the general effect of their wearing a rather demented wig. After the breeding season ends this is shed, and they become slightly more normal looking.

Bristol Zoo is involved with several conservation projects in the Philippines. As well as the Tarictic Hornbills and now the Warty Pigs, the zoo has worked for many years with the various Bleeding Heart Doves and their relatives, three of which, the Luzon Bleeding Heart Dove Gallicolumba luzonica, Mindanao Bleeding Heart Dove G. crinigera, and Sulawesi Ground Dove G. tristigmata, can be seen at Bristol. In addition the zoo supports an in situ breeding project for the Negros Bleeding Heart Dove G. keayi.
Sulawesi Ground Dove
Next week, I will begin a series on the zoos’ other site, opened a year ago and still in development, the Wildplace Project.

(images from Wikipedia)

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