Hutton's shearwater (Puffinus huttoni; also known in Māori as kaikōura tītī) is a medium-sized ocean-going seabird in the family Procellariidae. Its range is Australian and New Zealand waters, but it breeds only in mainland New Zealand. Its conservation status is Endangered, because there are just two remaining breeding colonies, located in the Seaward Kaikōura Range. Six other shearwater colonies have been destroyed by introduced pigs. Hutton's shearwater is the only seabird in the world that is known to breed in alpine areas. Conservation measures for the bird include predator control at the breeding sites, establishing the Kaikōura Dark Sky Sanctuary, and community initiatives to rescue birds that crash-land at night on streets in Kaikōura. A protected breeding area has also been created on the Kaikōura Peninsula, including a pest-exclusion fence and man-made burrows, with the initial population established by translocating fledglings from the remaining breeding colonies.

The bird's name commemorates Frederick Hutton, a former curator of the Canterbury Museum in Christchurch, New Zealand. A medium-sized (350 g) seabird, with a 75 cm wingspan, it is brown with a white underbelly and brown collar, dark borders to the underwing, dark grey bill, and pinkish dark-webbed feet. It can be distinguished from the fluttering shearwater by its dark grey "armpits". At a breeding colony it has a loud cackling call.

Hutton's shearwater feeds in the open ocean largely on small fish and krill, diving up to 20 m. Puffinus huttoni have long bills, which are adapted to catch prey more or less underwater by plunging from a few metres above the surface or by paddling slowly forwards searching with their head submerged, then diving using partly opened wings for propulsion.

These birds live entirely at sea except when breeding. During the September–March (spring and summer) breeding season, adults migrate to New Zealand waters. There have been individual sightings around the entire New Zealand coast, but most birds feed off the eastern South Island, especially between Cook Strait and Banks Peninsula. Large flocks can be seen off the Kaikōura coast during summer. Outside the breeding season, they are mostly found in Australian waters. Geo-locators fitted on young birds revealed that some circumnavigate Australia in an anti-clockwise direction in the 4–5 years leading up to sexual maturity.

Uniquely amongst seabirds, Hutton's shearwater breed in sub-alpine to alpine zones, making them one of the few New Zealand seabirds to breed solely on the mainland. Their burrows are at an altitude of 1,200–1,800 m. They formerly bred in both the Seaward and Inland Kaikōura mountains in historic times, and Māori collected the young "muttonbirds" before they could fly for food. Comparing extant and extinct colonies, the key difference is the presence of introduced wild boar. The birds are absent from New Zealand waters outside of the breeding season and adult birds start returning from Australia in late August. Their breeding is restricted to only two remaining colonies in the Seaward Kaikōura Range, one colony of over 100,000 pairs at the head of the Kowhai River, and one small (8,000 pair) colony on private land at Puhi Peaks station, near Shearwater Stream. Intraspecific competition has been observed between male conspecifics as they will defend their burrow from others. Although the species was scientifically described in 1912, its breeding colonies were only rediscovered by Geoff Harrow in 1964. Burrows are dug into steep tussock slopes at a density of 1 per 2 m². Hutton's shearwaters burrows are simple and non-branching. Kowhai Valley colony burrows are dug on slopes varying from moderate to steep: because the soil here is deeper and friable, shallower slopes are less suitable for burrows.

The most reliable method of measuring breeding success and burrow occupancy is with inspection hatches. Even though this causes a disturbance, the birds can tolerate it well. Over 70% of burrows are occupied by an incubating bird during the early stages of the breeding period. Most breeding pairs will lay one white egg in November which is incubated for 50 days. The responsibility is shared by both sexes; chicks will be fledged in around 80 days. Egg laying within a colony is non-synchronous. Mid-November is the early incubation stage while late incubation occurs in early January. Chick rearing is also from early January and ends in late February. Seasonal variation affects the rate of mass gained by chicks during the fledging period. Annual adult survival has been estimated to be 93.1% with breeding success averaging 46.5% but Puffinus species breeding in introduced predator-free environments have comparable breeding success and adult survival rates. Breeding success in the Kowhai Valley and Shearwater Stream colonies during the 2006/07 and 2007/08 breeding seasons were lower than in the late 1990s even though burrowing occupancy rates were similar. Shearwater Stream breeding success was significantly lower than Kowhai Valley for both of these breeding seasons despite efforts to control stoat population, indicating that predation is not the primary cause of breeding failure. In the case of breeding failure and an unviable egg, a replacement egg will not be laid.

Many shearwater species' feeding strategies are an intermediate between pursuit diving and surface feeding. Hutton's shearwater's foraging strategy is exclusively pursuit diving as they dive for prey. On average, birds will dive to a depth of 5.6 m, but they can dive as deep as 35 m. Birds that are incubating will dive deeper than birds that are feeding chicks. When at-sea feeding conditions are poorer, breeding success is lower so there is selective pressure on adult birds to forage adequately.

Individuals have been observed foraging with red-billed gulls, black-backed gulls, white-fronted terns and Hector's dolphins but with varying diving depths and prey preference, niche differentiation may be occurring. Hutton's shearwater will nearly always dive during the day, indicating that vision is a large part of their foraging strategy, with rare night-time dives happening within 72 hours of a full moon. Dives occur as early as 5am and as late as 10pm, while rafting occurs from 10pm until 5 am. Rafting helps to conserve energy when they cannot forage without light. Minimal movement during rafting confirms the birds are not foraging at all, supported by the fact that birds do not raft in the same area as they forage and go to areas with deeper waters than their foraging locations. Diving depth and frequency both vary with time of day and breeding stages with dives being more frequent around dawn and dusk, consistent with the diurnal vertical migration of prey species, but dive frequency between 6pm and 8pm during the chick rearing period is significantly reduced. Less frequent dives at dusk for other seabirds could be to reduce energy expenditure during foraging by allowing potential prey to return to the surface or because birds are returning closer to their colony before foraging as more energy is required to carry resources from a greater distance.