22 February 2012
The enigmatic New Zealand storm petrel was brought off the extinction list in 2003, when it was sighted first off Whitianga then in the Hauraki Gulf. Since that time, the tiny, swallow sized bird has been conducting its business hidden from the gaze of all but the keenest bird watchers, and its breeding site remains a mystery. The birds are expected to nest in crevices in rocks, and would be highly vulnerable to introduced predators, making it difficult to find their well-concealed nests. At-sea sightings have proved more fruitful for locating the species, with many encounters in the Hauraki Gulf in recent years, the latest of which confirmed that the birds are likely to be breeding in New Zealand. Birds caught in early February 2012 had bare brood-patches on their bellies, a condition only encountered during the breeding season.
Te Papa sponsored a recent search for the breeding site, drawing on the experience of their seabird research team. The trip was led by Jean-Claude Stahl who has spent many years researching similar species in the French sub Antarctic Islands. The team included experienced storm petrel chasers Chris Gaskin (Kiwi Wildlife Tours) and Brett Rathe (Assassin Fishing Charters). They searched the sea at dusk off two likely breeding sites in the Hauraki Gulf: the Mokohinau Islands and Little Barrier Island. The trip was timed to coincide with the predicted hatching period of New Zealand storm petrels and at a time close to new moon. On dark nights the birds are likely to go ashore soon after sunset, and so should be visible close off shore when it is still light. On bright moonlit nights the birds may not go ashore until late at night when the moon sets, to minimise predation risk.
The team left Sandspit near Warkworth in the morning and headed to a known feeding ground north-west of Little Barrier. No birds were seen there, but several were sighted over reefs south and north of the Mokohinau Islands. These and previous observations around the Mokohinaus gave some hope that the species breeds somewhere in this island group. However none was seen by the team during a systematic dusk survey around all islands in the group. This does not bode well to finding a major breeding colony in this island group.
As a last throw of the dice, the team decided to head to another station just off Little Barrier Island late on Monday evening. There, the first New Zealand storm-petrel was seen circling around the boat within minutes, and up to six were attracted later on, one of which was caught and banded. This location was not far from where another bird previously flew onto a boat anchored off Little Barrier Island. These observations point to Little Barrier Island being the best prospect so far for finding a breeding colony of this elusive bird.
Contact: Susan Waugh, Senior Curator, Natural Environment, Te Papa ph 029 770 6498