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SCIENCE & IT
Hanging on by a talon A Charles Sturt University researcher studying a rare owl in southern Australia has found it is barely hanging on in its natural habitat, after recent assaults through major drought and bushfires.
Baby Barking Owls in North East Victoria The incessant trilling of baby Barking Owls heralds the nearby nest. “These are my ‘bombproof’ owls, the ones least disturbed by human presence,” says Charles Sturt University researcher Natasha Schedvin, making a quiet path though a forest of black cypress pine and gum trees. Later, the female swoops from tree to tree, issuing a warning call that explains why these owls are also called the “screaming woman” owl. There are three chicks in this nest in the hollow of a dead tree, but only two appear. These are the lucky ones. CSU wildlife researcher, Natasha Schedvin searches for Barking Owls. Ms Schedvin is a PhD student at CSU’s School of Environmental and Information Sciences on the Thurgoona campus in NSW and a member of the University’s Johnstone Centre for Research in Natural Resources and Society. For the past three years she has been studying Barking Owls, an endangered bird in Victoria, threatened in NSW and rare in South Australia. Over this time, she has tracked 13 owls for 130 nights in and around Chiltern-Pilot National Park in North East Victoria. Up until the huge bushfires of 2003, this area had one of the densest populations of Barking Owls in south-east Australia. This particular breeding pair is the most successful of the 23 pairs Ms Schedvin has studied. Over the past four years they have raised three chicks annually, the most that Barking Owls can produce each year. Fortunately this prolific pair and their tree were spared in the fires which burnt much of the owls’ natural habitat and destroyed six other nests. One reason the bushfires were so devastating is these owls are very territorial and do not move to new locations easily. Breeding pairs stay and defend their patch at all cost. “The situation last breeding season was very poor,” Ms Schedvin says. “The study population of 23 pairs is now down to nine, and of those pairs, only two successfully produced young this year. And there are no owls nesting in the burnt areas. “The impact of drought is felt for some time after it finishes as the bush recovers. I expect the combination of drought and fire has resulted in fewer food sources when the owls are breeding.” An adult bird on lookout. A key factor contributing to the previously abundant Barking Owl population is the large connected blocks of box-ironbark woodland present in Chiltern-Pilot National Park and its surrounds in North East Victoria. “It’s one of the major forest types we’ve lost a lot of in Australia,” says Ms Schedvin, whose research looks at the owls’ habitat requirements to help management the remaining wild populations. The Barking Owl was once found across southern Australia. It is now found in larger forest remnants and in the river red gum forests along the Murray. “They are declining in southern Australia but not in the north and we don’t know why, though we suspect clearing woodlands into smaller fragments is having an impact,” says Ms Schedvin. Owls are at the top of the food chain, eating bats, possums and parrots and other endangered species such as squirrel gliders. “Given this varied diet, you would expect them to do well in all sorts of environments. So the question is, ‘why aren’t they?’” she says. “They like the edges of woodlands next to pastures, more fertile sites and strips along the drainage lines. This country is productive and provides more prey for them to live on. I hope to show that it is the characteristics of the bird’s habitat that is affecting their survival.” Barking Owls use large old trees as nesting hollows, as does most of the wildlife they prey on. These hollows are also a limited resource in many areas as these old trees have been cleared. “We don’t know much about Australia’s large forest owls,” says Ms Schedvin (pictured left). She said her ongoing work aims to fill in some of the gaps. ends Author: Wes Ward
Editor's Note: It is with deepest regret that Charles Sturt University notes the recent passing of Border Mail photographer Alex Massey, who took the first photo in this article. The University will sadly miss his professional contributions to the local media and his creative eye for the "great shot". Vale, Alex. Related Images:  Related Documents: |
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