Saturday, 13 September 2014

Wildplace 4: Pigmy Goats

Pigmy Goat
One of the longest domesticated animals (after the dog) in the world is the domestic goat. From its original home in Asian mountains, it has travelled with humans all over the world, and unfortunately it is also one of the ecologically destructive. Despite this, it is also one of the most useful of all domestic animals, as its appetite for vegetation of all kinds makes it a prime converter of inedible plants into meat that humans can eat, and milk that they can drink. With such a long history, numerous breeds have been developed for more specialised purposes, from dairy to wool to meat. At Wildplace the goats are part of the Malagasy Village, and are one of the most commonly seen breeds in a display situation, the Pigmy Goat.

Originating from dwarf breeds of goat found across tropical Africa, the Pigmy goats seen in Europe are derived from a mixture of slightly different local varieties, although the West African breeds are probably the main source population. In the UK these have now been combined into a single breed standard which is run by the Pigmy Goat Club of the UK (there is a separate club for the US). In their home countries they are mostly meat animals, but in the UK and USA they are kept as pets.

Pigmy Goats get their name from their miniature size – they stand well under 60cm at the whithers – which seems to be a result of a variety of different mutations. The West African forms have more or less normal –sized bodies but shortened legs. This is referred to as the achondroplastic type, as it seems to be similar with humans with that condition. Sudanese dwarf goats have a more normal appearance but are reduced overall, the pituitary hypoplasia type. Whether either of these forms are a result of simple mutations is unclear. Although their smaller size makes them easier to manage, in the home countries one of their most important features is that they are trypanotolerant, which means they are resistant to the effects of infection with Trypanosomiasis, caused by various species of Trypanosoma, spread by Tsetse flies, Glossina spp.. Most native African wild animals are resistant to the disease as well, but most cattle breeds are susceptible, although a few, especially in West Africa, are also trypanotolerant.
Tstetse Flies

Goats are longer lived animals than many people think – they can live to 15 years, although 10 or so is more usual. Being originally mountain animals, they are very agile, and can easily climb trees to reach the foliage if they can jump up to a low enough branch. They are basically browsers rather than grazers, and prefer the leaves of broaf-leaved weeds, woody shrubs, or even bark rather than grass. This is of course why they can be so ecologically destructive, especially on islands, where they can basically eat anything they can reach, and rapidly multiply until the islands are as bare and leafless as their original mountain homes. Removal of goats from islands is one of the first tasks of any island restoration project, as they invariably compete with native herbivores (often tortoises) to the latters detriment.

Bristol Rock Cress
Despite the destructive effects of goat overgrazing, they can also be used in more ecologically beneficial ways. Here at Bristol a small flock of goats have been translocated from a feral herd in Wales to a fenced off area of the Avon Gorge, where they are used to prevent regeneration of scrub and aid the regeneration of habitat for several locally threatened wild plants such as the Bristol Rock Cress, a species of Arabis unique to the area.
Next time – Wolves
Images from, Wikipedia, my own photos

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