Native birds feel no fear when facing foes

Dec 17, 2008
Native birds feel no fear when facing foes
North Island Robin.

(PhysOrg.com) -- Endangered native birds are at risk of losing their instinct to recognise and flee mammalian enemies when moved between predator-free and predator-filled sites, says a Massey researcher.

Sarah Whitwell, a biology Masters student at Massey's Institute of Natural Resources in Albany, designed an experiment using a pulley system to dangle a stuffed stoat and morepork at nesting North Island robins to test their fear responses. She says most robins in areas free of introduced predators, such as stoats, failed to get into a flap at the sight of an enemy, albeit a fake version.

Her research adds to growing evidence that native birds' responses to mammalian predators are not genetically hard-wired.

“That's because introduced mammal predators have been here a relatively short time, whereas native birds have been here for millions of years.”

She says already endangered native bird species would be at increased risk if moved back to wilderness sites with mammalian predators after inhabiting mammal-free conservation areas without some form of predator-recognition training.

The responses of robins in predator-controlled Wenderholm Reserve and Tiritiri Matangi Island near Auckland were compared with those in the central North Island, where the birds have long co-existed with native and introduced predators.

Most of the robins in the predator-free zones did not react to the presence of the stuffed stoat but did react strongly to the morepork - a native predator with a long history of association with the robins. Real versions of both of these predators prey on native birds and their eggs and chicks.

Those in central North Island forest patches near Bennydale reacted to the stoat model by either flying away, or when there were eggs or chicks in their nests, by hopping, flicking or spreading their wings. In some cases, they called out to attract other birds to create a ruckus designed to scare the enemy.

“The birds at Bennydale could recognise the stoat because it's a predator they probably deal with on a regular basis. But those on Tiritiri Matangi who have been isolated from stoats for at least one generation have lost the ability to recognise the stoat as a result of isolation from them,” she says.

A number of endangered native New Zealand bird species - including kakariki, bellbirds and saddle-backs - now thriving in protected conservation offshore islands are being moved back to areas inhabited by predators in a bid to increase the population spread and gene pool.

“My research suggests there might be a need for birds from mammal-free areas to undergo pre-release training in predator recognition,” says Ms Whitwell.

This could be done by mixing birds from predator-free areas with birds capable of recognising predators in an enclosure, then using a mock predator to prompt a fear reaction. Fearless birds would model new behaviour by witnessing the response of birds whose fear instinct was active, she says.

She says although the stoat and morepork in her experiments were not real, they are still convincing enough to prompt real fear responses from the birds.

Provided by Massey University

Explore further: Insect mating behavior has lessons for drones

Related Stories

Tagging and scanning for feral pigs

Apr 17, 2015

Innovative research using GPS tracking and thermal imagery is being used in an attempt to manage the destructive behaviour of feral pigs in the south-west.

World's second most endangered turtle on road to recovery

Apr 16, 2015

Wildlife Conservation Society (WCS) and the Turtle Survival Alliance (TSA) announced today that 60 captive-raised Myanmar roofed turtles—a species once thought extinct—have been released into their native ...

First hatch of critically endangered species

Apr 15, 2015

Six tiny nestlings at San Diego Zoo Global's facilities in Hawai'i are being closely watched by conservation biologists. These six chicks represent hope for a small Hawaiian bird species known as the 'Akikiki. ...

Recommended for you

Insect mating behavior has lessons for drones

13 hours ago

Male moths locate females by navigating along the latter's pheromone (odor) plume, often flying hundreds of meters to do so. Two strategies are involved to accomplish this: males must find the outer envelope ...

Bacterial tenants in fungal quarters

23 hours ago

Ludwig Maximilian University of Munich researchers have sequenced the genome of a bacterial symbiont hosted by a mycorrhizal fungus. Analysis of the symbiont's genetic endowment reveals previously unknown ...

Natural enzyme examined as antibiotics alternative

May 29, 2015

In 1921, Alexander Fleming discovered the antimicrobial powers of the enzyme lysozyme after observing diminished bacterial growth in a Petri dish where a drop from his runny nose had fallen. The famed Scottish ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.