Wednesday, October 21, 2009

Diamantina - take two

Immediately after the Simpson trip I drove out to the Diamantina to meet up with a DERM research trip studying the ecological effects of cattle removal in the park. The park is home to wild populations of bilbies, Kowaris and Kultarrs. Kowaris are small quoll-like dasyurid marsupials - much like Mulgaras though inhabiting flat, ironstone and gypsum country rather than sandhills. Kultarrs are bizarre little things which look like a cross between a dunnart and a hopping mouse. They share the hopper's long, tufted tail and gracile back legs, but facial features reveal their true dasyurid nature.

Spencer's Monitor, Varanus spenceri

In addition to the excitement of trapping these wonderful small mammals, I was thrilled to pay a visit to Astrebla Downs NP. A bizzare flat, lightly grassed landscape, this park has long been used for bilby research. The best part was that, following good summer rains, long-haired rats (<I>Rattus villosissimus</I>) had erupted in the park. Rats were everywhere. By day, squeaking sounds came from every scrap of cover. At night, masses of rats scurried and bounded for their burrows when lit up by torchlight. Almost every square metre of earth was home to a rat burrow. The mass of rodents is a great boon for predators in the area - birds, snakes and mammals alike.

Long-haired rat, Rattus villosissimus

By day, a variety of raptors hung around, hopeful for a rat stupid enough to venture outside its burrow - black kites, brown falcons, black falcons, brown goshawks, spotted harriers. In the late afternoon the night shift started turning up - letter-winged kites.

These are very interesting raptors. They seem to be specialist predators of these rats - they only really turn up where the rats are erupting, and simultaneously breed like crazy themselves. Also, unusually for a kite, they're largely nocturnal.

This photo shows two adults (far right) and some juveniles - presumably their progeny. Astrebla's few trees almost couldn't handle the weight of breeding letter-wings.

And of course... the bilby

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