Shearwater Research Articles

Occupation of burrows as a means of estimating the harvest of Short-tailed Shearwaters in Tasmania

The harvest of Short-tailed Shearwater chicks during the 1977, 1978 and 1979 seasons was estimated by counting bur- rows along transects in colonies before and after the season. Analysis of results showed that only five transects, each 100 metres long, were required to estimate accurately the proportion of burrows occupied. During incubation in December the mean percentage of burrows occupied in the 1979 season was seventy-six per cent. Before the season opened in March, it declined to between thirty-five and sixty-five per cent each season. Counting in April after the season showed that, in the colony reserved for non-commercial or private use, over eighty per cent of the chicks originally present in March were taken but at the colony reserved for commercial purposes the mean crop over three seasons was thirty-five per cent. Short-tailed Shearwaters are in no danger from exploitation but some heavily harvested colonies could be.

Movements of Wedge-tailed Shearwaters off the Coast of New South Wales

A study of the movements of Wedge-tailed Shearwaters Puffinus pacificus in Sydney coastal waters was carried out over the six years 1968-73 inclusive. The birds, normally considered sedentary, gradually departed during April and were completely absent during winter. The first birds usually returned about 20 August with the bulk of the population arriving soon afterwards. Arrival dates at Coffs Harbour, 450 kilometres north, appear to be up to two weeks earlier. Evidence from banding and beach-washed birds supports the conclusion that pacificus is absent in winter. The significance of three recoveries of birds banded in New South Wales in the Philippines is discussed. The status of pacificus in Queensland and Western Australia is reviewed briefly and a historical record documented.

Inexperienced birds and breeding in the Cory's Shearwater (Calonectris diomedea)

Among the Cory’s Shearwaters (Calonectris diomedea) of Selvagem Grande (30°09′N, 15°52′W), the rates of temporary non breeding, change of mate and nest-site and breeding failure in inexperienced birds are out of proportion with the frequency of these birds in the breeding population. However, this frequency being low - 15 % over the last decade - the results at population scale are not much penalised and that inexperienced birds do not seem to be as much responsible for breeding malfunctions as one might be led to expect.

Shearwater taking food on land

Shearwater taking food on land

Buller's Shearwater on Cabbage Tree Island, New South Wales

Buller's Shearwater on Cabbage Tree Island, New South Wales

Shearwaters in South-western Victoria

Shearwaters in South-western Victoria

Mortality of Shearwaters

Mortality of Shearwaters

An Abnormal Tasmanian Shearwater

An Abnormal Tasmanian Shearwater

Shearwaters

Shearwaters

Occurrence of the Mediterranean Shearwater in New Zealand

Occurrence of the Mediterranean Shearwater in New Zealand