Storm petrel study paves way for new colonies

November 11, 2011

Storm petrel study paves way for new colonies

A Massey University biologist has been awarded a $2500 scholarship for her study on white-faced storm petrels on a remote island north of Auckland, which she says could pave the way for creating new colonies on the mainland.

Megan Young, a Conservation Biology Master’s student at the Albany campus, was awarded the scholarship by the New Zealand Coastal Society this month for her research on the breeding behaviour and chick development of the birds on Burgess Island, part of the Mokohinau Group about 100km northeast of Auckland.

She says her data will provide a clear understanding of how the tiny birds – also known as Jesus birds because of the way they use their feet to hop, skip and walk on water – nest, feed their young and how chicks develop through to fledgling stage. The knowledge will be available to groups such as the Department of Conservation and community groups wanting to translocate fledgling petrels to protected reserves, for example, at Cape Kidnappers, says Ms Young.

Because petrels are faithful to one nesting place, they would have to be moved as fledglings before the site-specific “imprinting period” when they develop the ability to identify with their birth site. Her research will enable conservation managers to determine when is the best time to carry out a translocation.

She will spend six weeks on Burgess Island in January and February next year measuring and weighing 90 chicks to assess how fast they develop and how much food they need. The information will update the only other New Zealand study of the species, done in the 1940s.

There are an estimated 5000 to 10,000 breeding pairs on Burgess Island, with other colonies around New Zealand’s coastline as well as on the Auckland and Chatham Islands. The biggest colony is on Rangatira Island in the Chathams group, where there were estimated to be 840,000 breeding pairs in 1994.

“There would probably have been millions of them all over New Zealand once, but many populations have been lost because of predators [cats, rats, stoats and possums] and habitat loss,” says Ms Young.

She says petrels are important as “ecological drivers” because they bring nutrients from the ocean to the land and in their colonies they modify soils and vegetation.

Doing the research requires hiring a boat (or a helicopter if the weather is too bad for sailing) to reach the island, and climbing over narrow rock bridges to reach the colony. Finding bird burrows is not too difficult, and it is easy to briefly remove chicks for weighing and measuring while parent birds are out fishing during the day. Adult birds weigh just 50g and are roughly the size of a song thrush.

Ms Young says she was “very excited and grateful” to receive the scholarship. “This project is expensive largely due to the remoteness of the study site. The money will help me to buy field equipment, have lab analyses done on blood and DNA samples, and with provision for volunteers giving up their time for this project.”

ENDS

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