Conservation efforts must be ramped up to save populations of a quirky native seabird species clinging to survival on Auckland coastlines, a leading ecologist says.

Today, Auckland Council rangers will walk a specially trained dog from Bethells Beach to Muriwai in the first formal survey of grey-faced petrel populations on the Auckland region's mainland.

It comes after night-time expeditions to two coastal spots at the edge of the Waitakere Ranges found colonies of the seabird were struggling to survive in the face of attacks by stoats, rats and cats.

Auckland University ecologist Dr James Russell said they have only just been announced a unique New Zealand species, after a genetic analysis showed they weren't a subspecies of the more widespread great-winged petrel.


He said the large, docile birds were mainly found on islands around the upper North Island, but conservationists had only recently discovered some mainland colonies had held out.

While New Zealand is thought to have more than 100 colonies still, most sites have fewer than 500 breeding pairs. Around Auckland, sites include Piha, Karekare, Muriwai and the Cornwallis Peninsula, where only about a dozen burrows have just been found.

Dr Russell believes these secret colonies have benefited from predator control in the area by council and community groups - although the species' quirks had helped.

Being winter breeders, the birds return to their colonies, burrowing underground at night, just as pest populations crash over the colder months.