Protecting native birds by manipulating rats' sense of smell

Oct 17, 2012
The researchers manipulated the rats' sense of smell to keep them from preying on vulnerable species. Credit: Mal Weerakoon

(Phys.org)—Rats' keen sense of smell can be exploited to dramatically reduce their attacks on native birds, researchers from the University of Sydney have shown. The technique could be adapted to protect vulnerable species worldwide.

"Introduced (Rattus rattus) are a major threat to the conservation of many bird species worldwide so a new method for reducing their impact is good news for conservation," said Dr Catherine Price, a Research Associate from the University's School of Biological Sciences.

Price is the lead author of the study, published in the on 16 October. Professor Peter Banks, also from the University's School of Biological Sciences was the other contributing author.

"Working with wild populations of black rats in the bushland of Sydney Harbour and Lane Cove National Parks in NSW we discovered that we could increase the survival of birds' eggs without removing a single rat.

"An added advantage of this method is that it is not lethal to the predator. That means it is especially suited to protecting a vulnerable when the predator is also endangered or under threat," Price said.

Mammal predators live in a richly layered world of smells and have to learn to detect and recognise immense numbers of odours and distinguish minute differences between them. That ability could stop them being successful predators if they were not also able to quickly and efficiently disregard superfluous information.

"We exploited this ability in rats by exposing them to the of quail and feathers. In this case domestic quail were used as a stand-in for any new species of native bird because their smell would be unfamiliar to the rats," Price said.

"When the rats investigated the smell they found no live prey so their interest went unrewarded and after about three days they effectively lost interest in the bird odour."

The researchers then placed real quail eggs in artificial nests throughout the rats' habitat. They found they had a 62 percent greater survival rate than eggs that were introduced without first exposing the rats to the unrewarded quail smell.

By pre-exposing the rats to the smell they learnt to ignore a cue that did not bring any reward. This allowed the introduction of prey to occur without attracting the rats' attention and reigniting their interest.

"This technique of smell pre-exposure could be widely used in conservation. It has the potential to benefit many species currently threatened by rats, such as the North Island robin and red-crowned parakeet in New Zealand. We hope it can also be used to help protect endangered Australian species, such as greater stick-nest , burrowing bettongs and even loggerhead turtles against a range of introduced mammal predators.

"Our research introduces a different approach to pest management which manipulates normal predator behaviour. We hope it encourages others to think outside the square to tackle conservation problems."

Explore further: Zooming in for a safe flight: Study investigates spatial orientation in bats

Related Stories

Smelling a rat to catch a rat

Mar 24, 2008

A novel experiment using laboratory rats to attract wild rats could pave the way for “rat perfumed” bait capable of reducing the millions of rats threatening New Zealand’s native species, say Massey ...

Plague on their house, but bush rats fight back

Nov 03, 2009

(PhysOrg.com) -- Sydney's native bush rats were unintended victims of a campaign to exterminate foreign black rats during a plague epidemic in 1900, according to new research by scientists who plan to reintroduce ...

Bush rats fight back

Nov 10, 2009

(PhysOrg.com) -- Sydney's native bush rats were unintended victims of a campaign to exterminate foreign black rats during a plague epidemic in 1900, according to new research by scientists who plan to reintroduce ...

Scientists nail quail mystery

Oct 23, 2009

(PhysOrg.com) -- A Massey biology researcher has used DNA analysis to prove quail on Tiritiri Matangi Island are Australian and not remnants of an extinct New Zealand species.

New Zealand bird outwits alien predators

Jun 04, 2008

New research published in this week's PLoS ONE, led by Dr Melanie Massaro and Dr Jim Briskie at the University of Canterbury, which found that the New Zealand bellbird is capable of changing its nesting behaviour to protect ...

Recommended for you

Danish museum discovers unique gift from Charles Darwin

Aug 29, 2014

The Natural History Museum of Denmark recently discovered a unique gift from one of the greatest-ever scientists. In 1854, Charles Darwin – father of the theory of evolution – sent a gift to his Danish ...

User comments : 0