Fluttering shearwater

This is a medium to small-sized shearwater with a dark-brown-and-white body. The upper parts, including neck, wings and tail, are uniformly dark brown. The face and neck have a grey-brown colour gradually fading into white below the eye. The under body, from chin to the under-tail, is white except for a dark thigh patch that can be seen in flight. The bottom wing is commonly white while the axillary area is covered in grey-brown fur. Under light conditions, the appearance is different. The fluttering shearwater has pinkish-brown legs and feet with dark webs, and the feet extend beyond the tail in flight. The bill is long and thin with dark colour. Their eggs are pure white and oval. == Distribution and habitat ==

Global range Fluttering shearwaters are an endemic species to New Zealand, where they breed throughout the warmer months of the year, from September to February. However, during the non-breeding months of the year, between March and August, vast numbers are seen throughout eastern and south–eastern Australia, though most seem to linger close to the breeding colonies. They are most commonly found in subtropical waters and warm water (24 °C) of intermediate to high salinity (35%). The birds are common on inshore areas that are easy to enter such as harbours, inlets, bays and straits. They usually select stony, scrub-covered slopes near the peak, as well as cracks and holes in the rock far from the water to breed, which is a benefit for taking off. == Life cycle/phenology ==

Breeding Surprisingly, very little is known about the breeding biology and phenology of fluttering shearwaters. However, it is known that fluttering shearwaters, like most birds, are monogamous in that they breed with one mate throughout their life. Fluttering shearwaters start to breed when 4–10 years old and the breeding season runs from August to January. They nest in burrows and the nest chamber is made of dead leaves, grass, feathers and shoots. Their burrows are comparatively shallow and they usually built burrows in fragile soils, so if people move around their breeding areas, burrows are easily destroyed. To protect them, access should be strictly restricted. The male then inseminates the female which fertilises the ova, resulting in a fertilised egg. A singular egg then hatches external to that of the mother. Some birds stay at colonies throughout the year but most birds fly to colonies in August to woo and sweep burrows for breeding. After mating, females leave colonies for one to six weeks for forming eggs. Males also leave but return to nest sites a few times. Eggs are laid from early September and to mid-October. Usually they lay one white eggs in a burrow or occasionally in crevices and holes among the rock. Sometimes there are two eggs in one nest because two females share a site. Males and females incubate eggs together and eggs hatch in November. Fluttering shearwater chicks stay in their burrows and 'wing exercise' in the weeks before fledging. Once they have flown, they are totally independent of their parents. Migration In the post-breeding season, many birds migrate to parts of eastern and south-eastern Australia. It is suspected that it is only the juveniles that take part in this migration, with the adults remaining within New Zealand and staying within a relatively close proximity to the colonies. They only breed in New Zealand. == Behaviour ==

Fluttering shearwaters have a habit of fluttering their wings quickly and beat the feet when they fly away from the sea. A large group of fluttering shearwaters gather together and sit on the water in rafts through the months of mid-December, January and February. Sometimes, rafts will form just near the coastline. == Feeding ==

The fluttering shearwater's diet consists mostly of schooling fish (such as pilchards, trevally, mackerel, sprats, etc.), small pelagic crustacea (e.g. krill) and squid. Many members of the genus Puffinus have evolved to have heavier wing loadings in order to aid them in pursuing prey to greater depths underneath the water. == Predators, parasites and diseases ==

Chicks of the fluttering shearwater were caught by Maori until a government request to protect them in 1953. The predators of fluttering shearwater are mammalian animals such as cats and rats. == Threats and conservation ==

Anthropogenic threats Humans pose the biggest threat to fluttering shearwaters. Their conservation status is ranked as least concern; however, their population continues to decrease at a steady rate. Translocation to establish a new colony Petrels, along with other types of seabird exhibit natal philopatry - they return to their natal colony to breed. This means that the loss of a breeding colony through predation, landslides or human interference can have severe consequences for the population. Conservation initiatives for endangered seabirds include attempts to establish new breeding colonies by translocation from existing colonies, and hand-feeding of the chicks before they fledge. Burrow-nesting seabirds such as shearwaters play an important role in the ecosystem of many New Zealand islands. The birds enrich the soil in the breeding colony with nutrients from the sea through their guano and regurgitation. These nutrients feed invertebrates, and this in turn feeds lizards, tuatara and land birds. Translocation of chicks to establish new breeding colonies is also part of long-term strategy to restore the environment, including offshore islands that were once farmed but are now protected areas. Between 1991 and 1996, 334 fluttering shearwater chicks were moved from Long Island in the Marlborough Sounds to Maud Island. Artificial burrows were constructed at the new site, and the chicks were fed until they were ready to fledge. Experience with translocation shows that some of the chicks that are moved to a new location before they fledge may return as adults to breed at the new location. The proportion of translocated birds that return to breed at the new site appears to be closely related to the weight of chicks and duration of time they spent at new colonies. Chicks of higher weight and that spent more time in the new location before fledging are more likely to return to breed at the new site. Further research on translocation will focus on increasing weight and length of stay time. The establishment of new colonies (particularly in predator-free locations) will help ensure the survival of fluttering shearwaters. In January 2022, 50 chicks were translocated from the Long Island – Kokomohua Marine Reserve in Queen Charlotte Sound to the Wharariki Ecosanctuary at Cape Farewell. The transfer was the result of a collaborative project between HealthPost Nature Trust, the Department of Conservation and Manawhenua ki Mohua, which represents Ngāti Tama, Te Ātiawa and Ngāti Rārua in Golden Bay. == References ==