The grey-faced petrel/ōi breeding season is looking hopeful this spring at Bream Head, at the far reaches of the Whangārei Heads peninsula (Image: Scott Brooks).
This taonga sea bird is endemic to the North Island of New Zealand and only breeds at a handful of mainland colonies scattered around the coasts of the upper North Island, mainly on headlands and peninsulas. Bream Head/Te Whara Conservation Trust (BHCT) has been monitoring ōi burrows at three study sites since 2016.
In November Jess from Kiwi Coast joined BHCT ranger Tom Grinsted on his fortnightly visit to the study sites. One of the tasks was to burrow scope for chicks.
Jess reports “Burrow scoping involves using a camera on a long wire to investigate chick presence in the burrows. At the first study site, we found six chicks out of the eight burrows scoped. This is a promising sign as the chicks are extremely vulnerable to predation, nesting underground, often in burrows with only one entrance.”
BHCT have been linked into the Kiwi Coast network since its inception and have sustained an intensive pest control regime for many years. Tom shared that one of the stoats trapped in the area this winter was caught using Ratabate (diphacinone) as one of the lures in a DOC 200 trap.
Tom explains “While not your usual stoat delicacy, the belief is that the scent trails left by other rodents visiting the trap were enough to lure the stoat in. In the past, stoats have predated all the oi chicks just before they fledged – so as well as using traps and toxins, we also like to trial new, innovative ideas to ensure we catch as many of these cunning creatures as possible.”
In the next couple of weeks a specialised team will go out to the burrow sites to weigh and band the chicks. Fledging occurs from December to January, and the chicks will come back to the same burrows when they breed, usually at 8-10 years old.
Trail cams have been set up outside the burrows to monitor activity. Going through the footage, Tom and Jess spotted a kiwi cruising past one of the burrow entrances – another indicator of the success of predator control at Bream Head.
