About the Hutton's Shearwater

Hutton’s shearwater is an endangered seabird endemic to Kaikoura. The only place in the world that this species breeds is high in the Seaward Kaikoura Ranges at elevations between 1200 to 1800 metres.

When the Hutton’s shearwater was rediscovered by Trustee Geoff Harrow in 1964, there were eight colonies but only two survive now - on conservation land in the headwaters of the Kowhai River and on private land in Shearwater Stream.

Description

The Hutton's shearwater is a small "black and white" shearwater, 36-38 cm in length with a wingspan of about 75 cm.  The upperparts are uniform brownish black.  The dark brown of the cap extends below the eye merging into the white of the chin and throat.  The dark hindneck extends down behind the cap to form a broad collar almost encircling the neck and upper breast.  The rest of the underbody extending from the lower breast to the undertail coverts is white except for a small dark patch on the thigh and the sides of the undertail coverts. The underwing is offwhite with broad brownish borders with extensive dusky grey armpits.  Bill is long, slender, and dark grey. Iris brown. Leg is light to dark pink and mauve on the inside and pink and dark grey outside; feet pink with black webs.

Life cycle

An adult pair of shearwater will lay a single egg anywhere between the end of October to mid November. The egg is laid in a hollowed out chamber at the end of a burrow up from 60cm to 250cm in length. The nest is made of tussock grass and sticks, lined with feathers. The eggs are incubated for 50-60 days and the chicks, covered in soft grey down, are raised by both parents for 80 days until they are ready to leave the nest. When the chicks have reached a suitable weight and are fully feathered, they will leave the colony at night and fly to the ocean. From this moment they are totally independent of their parents. It is thought that shortly after this time the fledgling will leave the country and fly to Australia, returning after 3 or 4 years to breed. Adults also make this journey every year but stay only for the non-breeding season.

The Mountain Colonies

Only two natural Hutton's Shearwater Colonies remain, both of these colonies are found in the Kaikoura Ranges. These colonies are on land in the headwaters of Kowhai River and Shearwater Stream. At 1200 to 1800 metres these are some of the highest breeding seabirds in the world. The larger of these two colonies is Kowhai, at an estimated 106000 pairs; its smaller counterpart, Shearwater Stream, has around 8000 pairs. These two colonies are the last remaining of eight that were once located on these mountain ranges. After the bird was thought extinct, Shearwater Trustee Geoff Harrow rediscovered these eight in 1964. It is thought that the Hutton’s Shearwater once colonised the lower Kaikoura regions, but now the only natural remnants can be found at the tops on these mountains.

The Peninsula Colony

In the autumns of 2005 through 2008, nearly 300 shearwater chicks were brought down from the mountain colonies to new homes at the Kaikoura Peninsula colony.  These chicks were fed sardine smoothies daily until they were ready to fly to the ocean of southwest Australia. The first record we have of a bird returning to the peninsula colony was in December 2008. More birds returned in summer 2009-10 at the time a predator-proof fence was being erected.  This fence was completed in February 2010 and an intensive pest eradication programme undertaken in June 2010.  This work has been just in time as in November 2010 the first egg was laid by one of the translocated chicks in one of the nestboxes.