The New Zealand Storm-petrel has been found breeding near Auckland over 150 years after it was lost and thought extinct.
Last week, a mystery was finally solved, when the breeding grounds of the long-lost New Zealand Storm-petrel were discovered. This exciting news took me back to memories of my own first encounter with the species in December 2011.
After several hours of stomach-wrenching, gut-churning, rolling around in the back of a trawler, soaked to the skin, we finally saw our quarry, several miles out into the Hauraki Gulf, off Auckland, New Zealand. Storm-petrels always appear improbably fragile, pattering with delicate feet and fluttering wings over deep swell and immense waves. But this one had an even more tenuous grip on survival than most.
After a couple of specimens were collected in 1827, and another from the same century, the lack of any further records led the ornithological world to assume that the species had gone extinct. A similar fate had befallen so many other birds in a New Zealand, following the accidental and deliberate spread of invasive alien species like rats, cats and possoms, that this seemed entirely plausible.
It therefore generated much interest from the birding world in January 2003 when Sav Saville (our guide on the pelagic trip) posted a photo of a bird he and others had seen, which apparently resembled the long-lost storm-petrel. Before the year was out, a couple of enterprising UK birders, using chumming tricks they had honed on many trips out of the Isles of Scilly, found and obtained stunning photographs of up to 20 birds in the Hauraki Gulf. Forensic analysis of photos, further sightings, and DNA analysis of a feather from a bird that was caught by chance when it landed on a fishing-boat in 2005 proved the case beyond doubt. New Zealand Storm-petrel had survived for over a century and a half without anyone realising.
In the years that followed, more sightings began to fill in the picture of where the species occurred at sea, and how abundant it was. But the location of any breeding colonies remained a mystery. When we went out in 2011 in search of the species, Sav and other dedicated seabird enthusiasts had their suspicions as to which of the many offshore islands might be likely candidates. However, storm-petrels tend to breed in burrows and crevices, so their nests are difficult to locate. Worse, they only come ashore after dark. Pinning them down is like finding the proverbial needle in a haystack, while blindfolded.
Last year, a team of researchers began catching birds at sea using specially designed net guns. In February, they found birds with brood (incubation) patches, indicating that this might be the best time to find breeding birds on land. This year, the team led by Chris Gaskin - Important Bird Area Programme Manager for Forest & Bird (BirdLife in New Zealand) - and Matt Rayner from the University of Auckland, caught 24 birds at sea and fitted tiny radio transmitters. Automated receivers allowed them to focus the search, and handheld receivers and spotlights showed that birds were coming ashore after dark on the north coast of Little Barrier Island. Finally, they picked up a signal from a stationary bird in forest at night. Last Friday, they found a bird on the ground, possibly having just left its burrow, and got a signal from another bird, probably on its nest.
The exciting discovery now paves the way for identifying and implementing priority conservation actions for the species. Fortunately, probably the most important steps have already been taken: the eradication of cats in 1981 and pacific rats in 2004 on the island will have no doubt had a major benefit for the storm-petrel. Indeed, such programmes on islands in the region through the 1980s and 1990s presumably allowed the population to start to recover, and led to its rediscovery and the increasing number of records since.
This fantastic news re-emphasises both the biodiversity importance of the Hauraki Gulf Marine Park and the tremendous achievements of New Zealanders in conserving their wildlife in recent decades: an inspiration for bird conservation the world over.
Images: New Zealand Storm-petrel © Stuart Butchart
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