Sooty Shearwaters (Puffinus griseus, also known as Titi
or the muttonbird) are medium-sized burrow nesting seabirds
that breed on New Zealand's off-shore islands with a small
number still attempting to nest on the mainland.
Breeding colonies of Sooty Shearwaters are found around
the coasts of Southern South America and South-east
Australia. They are the commonest seabird in the New Zealand
Breeding range of Sooty Shearwaters within New Zealand
extends from the Three Kings Islands (34 S,172 E) to
Maquarrie Island (54 S, 159 E).
Breeding abundance in New Zealand centers around islands
in Foveaux Strait and islands adjacent to Rakiura (Stewart
Island, New Zealand's third largest island). Large
populations are also found on The Snares, with smaller
populations on other New Zealand Sub Antarctic Islands,
Chatham Islands, Antipodes, Auckland Island, Campbell Island
and Macquarie Island .
Sooty Shearwaters are vulnerable to mammalian predation
and as they lay one egg per year have a low annual
productivity. Colonies on the offshore islands have remained
large but colonies on the mainland have either contracted or
Sooty Shearwaters return to the colony after 3-4 years,
however the majority of Sooty Shearwaters do not breed until
5-7 years of age. The maximum longevity recorded is 34
years, supported by the recapture of 2 banded adults from
The Snares in the 1999-2000 breeding season.
Both breeding and non breeding birds return to the colony
in late September or early October for courtship and
preparation of burrows which may extend from 0.4 m to 4
meters in length. On average an adult Sooty Shearwater
weighs 819=76 grams.
When on land, Sooty Shearwaters are almost entirely
nocturnal, landing at dusk in the cover of darkness and
returning to the sea at dawn. Each breeding pair lays a
single egg, which is not replaced if lost or damaged.
Incubation is for approximately 53 days, the chick hatching
and spending the next 86-106 days in the burrow before
emerging, stretching wings and fledging from mid April to
late May, migrating to the Northern hemisphere. Further
information is available at http://nzbirds.com/Titi.html