The Common Diving Petrel has black upperparts and white underparts.  The sides of the face, neck and throat are mottled grey and the underwings are smoky grey.  The stubby bill is black and the legs and feet are blue.  They only call at their breeding colonies and the main calls are a harsh ‘kuaka-did-a-did’ and ‘kuaka’ given by the females only and ‘kooo-ah’ which is only given by the male.

They feed mainly on small krill and copepods.

Breeding occurs in large colonies on many off shore islands from Northland to Stewart Island, The Snares, Antipodes and Auckland Island.  In northern New Zealand breeding starts in August and from late September in the subantarctic.  The birds return to prepare their burrows from March until the end of May.  The single white egg hatches after about 53 days and fledges at 45 – 59 days old in late November – December in northern New Zealand and in January – February in the subantarctic.

With the spread of introduced predators these birds survive best on islands without mammalian predators.

Common Diving Petrel can be heard off the east coast of Tiri.

References: Heather, B.D.; Robertson, H.A. 2000 The Field Guide to the Birds of New Zealand. Auckland, Viking.
Moon, G The Reed Field Guide to New Zealand Birds.