Saturday, 28 July 2012

Miscellaneous Mammals 7: The Kowari

Just gone on show in Twilight World is the first marsupial we have had for several years: the Kowari Dasyuroides byrnei. It is a fairly typical member of the Dasyuridae, the diverse family of marsupial carnivores whose largest living member is the famous Tasmanian Devil, Sarcophilus harrisi. Most members of the family are shrew to rat-sized, but the various species of Quoll grow to about the size of a domestic cat. Unfortunately, with the introduction of true cats into Australia, plus other predators and competitors, has been very bad news for the dasyurids, and most are considered at least Near Threatened in the IUCN Red List.

A native of the Lake Eyre basin in central Australia, despite its rather mouse-like appearance the Kowaris is actually a small but voracious predator of insects, spiders, and small lizards and anything else it can catch. Growing to about 28, of which about half is tail, it lives in burrows either alone or in small groups (probably based on a pair plus young). The typical habitat is stony desert and dry grassland, where it is thinly spread. It is believed to be declining as a result of overgrazing, but as with many desert animals the populations shows extreme fluctuations depending on whether the recent weather patterns have been favourable or not. According to the latest IUCN estimates, the wild population is probably under 10,000 adults, and it is consequently classed as Vulnerable.

Range of Kowari
As with almost all desert mammals, it is nocturnal, emerging after dark to hunt. Its prey provides all the water it needs, but it may lick water droplets off stones when it is available. They are good climbers, and probably climb trees or bushes in search of bird nests. How far they range from their burrows each night is not certain, but the closely related Mulgara, Dasycercus cristicauda, can have a home range of up to 14ha.

Kowaris are quite prolific animals, with two litters of 5-6 young each year. The life expectancy in captivity is up to 6 years, but in the wild they probably live only one or two years at most. Their high reproductive rate compensates for the short lifespan. As a marsupial, they of course raise their young in a pouch. The young are born after a gestation period of around 30 days and are independent from around three months.

Although they do live in groups in the wild, in captivity Kowaris can be highly aggressive with each other outside the breeding season. Much larger enclosures than might be thought necessary for the size of the animal are best, as this gives them a chance to avoid each other. Except in large enclosures, Kowaris are often kept singly, only being allowed together during the breeding season. The captive diet is based around insects, egg, and rodents. As with many desert animals, they like to roll in sand to clean their fur, and this needs to be available. They also need branches to climb and a nestbox, with soft leaves abd hay to use as nest materials.

Bristol is the only zoo in the UK to hold Kowari at present. There are a few zoos in Europe which hold them, but the decision has been taken to increase the captive population and number of holders. It is intended that Bristol breeds from our animals and then distribute them to other British and mainland European zoos. This will enable zoos to use the Kowari as an exemplar animal for the condition of Australian mammals in general.

(images from wikipedia)

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