We were very lucky that our dear friend Vicki Sargesson, who passed away last year, was in the bush on Okewa headland late in the evening and heard a grey faced petrel landing. Following the sound with her headlight she watched as the bird moved into a burrow.
This led us to do a little more investigation and we found a small colony of nesting birds. What makes this finding so important is that these headlands on the Manukau Harbour have had colonies for many thousands of years, and the dedicated STNN pest monitoring has allowed us to find this small grey faced petrel colony.
We have four known breeding burrows but suspect there may be others, and will be keeping an eye, through our predator eradication program and tracking cameras, on the area to see if we can find more. The grey faced petrel's have one chick per year so each are precious. After the chicks leave the nest, some years later they return to breed where they are born.
James Russell from Auckland University has helped us formulate good pest eradication management to enhance the safety of the newborn chicks. STNN have now placed a tracking camera on the burrows to help establish which pests are coming close to the burrows, and to lay the best traps and bait to catch these pests.
More About Grey Faced Petrels
The grey faced petrel is a petrel endemic to the North Island. In New Zealand it is also known by its Māori name ōi. Protecting their burrows from animal pests are of importance as the fledging chicks will return to where they were born to bred and raise their own chicks. Increasing the population of the colonies.
The grey faced petrels begin returning to their colonies from mid-March but most birds don't start cleaning out their breeding burrows until April. Courtship peaks from late-April to mid-May. The breeding pair then depart on a pre-laying exodus that ranges from 50-70 days for females as they form their large single egg. The first eggs are laid from mid-June with incubation lasting about 55 days, a responsibility shared by both parents - swapping over about every 17 days. Males do two long shifts and females one long shift and typically return close to egg hatching. Chicks are left alone in burrows by day from 1-3 days of age. The parents may travel distances of up to 600 km in order to feed their offspring. The chick will be fed by the parents for about 120 days before fledging in December or January. After breeding the adults mostly migrate across to the seas off eastern and southern Australia to carry out their annual feather moult.
Finding and protecting native bird species is one of the key outcomes of our pest eradication program. If you'd like to find out more about trapping and tracking in your area please get in touch.