Introduced predators such as foxes and cats are twice as deadly as native predators to Australias unique native animals, a new study has found.
The new finding, published this week in the prestigious journal Proceedings of the Royal Society B, is the first confirmation of what has been a long-held hypothesis among scientists.
It also highlights the heavy continuing impact of these predators long after their introduction and that Australia's fauna has been among the hardest hit in the world.
Experts believe that introduced "alien" predators are more dangerous than native predators because their prey, such as numbats and bettongs, are nave to the hunting tactics of alien predators.
In contrast, where predators and prey have coexisted for long periods, prey often respond by developing behaviours and bodily defences such as camouflage colouring that reduce detection or help them escape if they encounter a familiar predator.
"The finding brings new insight and urgency to the challenge of how best to target management programs aimed at protecting native species from predation," says Dr Peter Banks, UNSW biologist and report co-author.
"More than a century after the introduction to Australia of predators such as the fox their impact continues, and ongoing predation pressure means that remnant populations of prey animals like numbats and bettongs are more vulnerable to extinction from other pressures such as diseases and habitat loss."
The study assessed the impact on alien predators on populations of animals, birds and reptiles by evaluating 80 high-quality research studies from around the world. Predators ranging in size from wolves, lynx and coyotes down to rats were included.
The research reveals that alien predators have done the most damage in Australia, whose native fauna have long been protected by the continent's geographic isolation. According to the World Conservation Union, Austr
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Contact: Dr Peter Banks
p.banks@unsw.edu.au
61-402-908-909
University of New South Wales
13-Mar-2007