Explosion of native rats in NT excites scientists

By AAP with AG Staff 7 April 2011
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The threatened native long-haired rat has been spotted around Alice Springs, to the delight of scientists.

THE SIGHT OF A rat is enough to make most people cringe. That is, of course, unless the person happens to be a scientist who can tell the difference between a common household scavenger and a rare rodent.

Most years, central Australia experiences an influx of insects and pests, but this year there’s a new visitor in town.

Sightings of the native long-haired rat (Rattus villossissimus) in Alice Springs have excited scientists from the Northern Territory Department of Natural Resources, Environment, The Arts and Sport.

Biodiversity conservation scientist Peter McDonald said the public should be aware of but not alarmed by the increased presence of these rats.

“These rats are native and, unlike the common house mice and introduced rats, they are not usually associated with human dwellings,” he said in a statement.

Rains bring the rats

Peter said it was very rare for long-haired rats to reach Alice Springs and that it may not happen again for another 20 or 30 years.

“They are rarely seen elsewhere in the NT; however, we believe that the rise in their population is due to the consecutive seasons of high rainfall. These animals are able to breed at quite a rapid rate due to all the fresh roots, stems and leaves that are currently on offer.

“The rodent prefers deep cracking clays or soft friable soils and requires food with high moisture content. We believe that once the weather dries up, the rats will again disappear.”

The last major population boom in central Australia, he says, occurred in the 1970s when long-haired rats were sighted at Uluru in the Northern Territory, Woomera in South Australia and Wyndham in Western Australia.

“This rat species has a very important role in the ecology of these boom and bust areas,” he said. “Plagues of rats are accompanied by large increases in predators, such as kites, owls and large snakes, which also benefit from a massive increase in the amount of prey available. Unfortunately, these days it can also mean a boom in the number of feral cats.”