Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Alien predators are more dangerous than native predators

15.03.2007
Introduced predators such as foxes and cats are twice as deadly as native predators to Australia’s 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 naïve 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, Australia has nine of the world's 14 worst invasive mammals (domestic cat, goat, grey squirrel, mouse, pig, rabbit, red deer, red fox, ship rat).

Scientists believe that more frequent contact between predator and prey populations in contiguous continents such as Eurasia, Africa and the Americas has made prey populations less naïve to alien predators by exposing them to similar predator "archetypes".

In contrast, Australia’s unique marsupial fauna have never had predatory species like feral foxes and cats until recently. Such alien predators were shown to have worse negative impacts than some classic predators, including large carnivores such as wolves.

Case study: foxes and the brush-tailed bettong

In the early 1800s, Australia’s brush-tailed bettong - a medium-sized kangaroo-like marsupial - was commonplace in central New South Wales, South Australia and the southern regions of the Northern Territory and Western Australia.

However, the population and range of bettongs began shrinking during the 1900s following the release and spread of foxes and rabbits across the continent. Many other species – up to two dozen -- are thought to have become extinct during this initial wave of invading alien species.

By the 1970s, the bettong was considered as an endangered species with the only surviving mainland populations found in small pockets of forest in Western Australia. However, even these remnant populations were still being preyed upon by foxes and by the late ‘70s the species was threatened with extinction.

Following an intensive program of fox-control initiatives, bettong numbers eventually rebounded by more than 20-fold, demonstrating that fox predation had continued to have a devastating impact on bettongs after more than 150 yeas. No native predator anywhere on earth has had such a profound negative impact on their prey.

Dr Peter Banks | EurekAlert!
Further information:
http://www.unsw.edu.au

More articles from Studies and Analyses:

nachricht The importance of biodiversity in forests could increase due to climate change
17.11.2017 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig

nachricht Win-win strategies for climate and food security
02.10.2017 | International Institute for Applied Systems Analysis (IIASA)

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>