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.