Gould's petrel  (Pterodroma leucoptera)

This species is classified as Vulnerable (VU) on the IUCN Red List (1).

A small and beautiful seabird which spends much of its adult life at sea, Gould’s petrel has a characteristic white forehead and contrasting ‘hood’ of black covering the crown and neck, with prominent ‘M’-shaped markings on its wings. It has a blue-grey mantle, turning darker grey on the rump, and a small, grey, rounded tail which is washed with brown. The upperwings are dark brown-grey, and the distinctive blackish ‘M’ shape extends across the back. The underparts are all striking white, including the underwings, which are edged in black and have a single dark diagonal bar running from the leading edge towards the middle of each wing (2) (3) (4) (5). Both sexes are similar in appearance, and young petrels resemble the adult birds (4).

Two subspecies of Gould’s petrel are generally recognised; Pterodroma leucoptera leucoptera in Australia, and Pterodroma leucoptera caledonica in New Caledonia. Pterodroma leucoptera brevipes from Fiji and the Cook Islands is sometimes considered a third subspecies of Gould’s petrel (2); however, most literature currently considers it to be a distinct species (Pterodroma brevipes) (1).

Gould’s petrel breeds on Cabbage Tree and Boondelbah Islands in Australia (P. l. leucoptera), on New Caledonia (P. l. caledonica), and possibly on the Austral Islands of French Polynesia. In the non-breeding season, the birds are thought to disperse throughout the Tasman Sea and to some parts of the Pacific and southern Indian Oceans (1) (3).

A primarily pelagic bird, Gould’s petrel returns to a small number of islands around Australia and New Caledonia during the breeding season. Breeding in colonies, Gould’s petrel nests in natural rock crevices, hollows in fallen palms and cavities among the buttresses of trees on Cabbage Tree and Boondelbah Islands in Australia, while in New Caledonia it nests on steep, vegetated slopes between elevations of 350 metres and 650 metres (2) (4) (5) (7). On Boondelbah Island, Gould’s petrel also breeds in artificial nest boxes (3).

Gould’s petrel arrives on Cabbage Tree Island, Australia, from mid to late September, and breeding occurs from November to March. A single egg is laid in early November, and incubation of the egg in shared between both sexes, taking 49 days to complete. Once hatched, the chick remains in the nest for thirteen weeks.  During this time, it is fed by both the male and female, becoming up to one and a half times heavier than the adult petrels, before fledging and leaving the nest in late March to early May (3) (4). Following the breeding season, both adult and juvenile birds leave the island to spend the remainder of the year at sea. Young birds remain at sea for several years, and first return to breed at around 4 to 5 years old (4). Gould’s petrel demonstrates high levels of mate and nest site fidelity, with the same pair of birds returning to the same location each year to breed (6).  

Gould’s petrel feeds mostly on cephalopods, krill and small fish, which it picks off the surface while foraging at sea. It has occasionally been recorded feeding in association with other seabirds, as well as with tuna and dolphins that drive prey to the surface (3) (4).

As Gould’s petrel is a ground nesting bird, it is particularly vulnerable to the threat of predation. On Cabbage Tree Island, rabbit grazing has removed all the understory vegetation around the breeding sites, leading to increased predation by avian predators, namely the pied currawong (Strepera graculina) and the Australian raven (Corvus coronoides) (3) (4) (5) (7). On New Caledonia, introduced pigs excavate chicks from nests, and cats and the black rat (Rattus rattus) predate eggs and adults (5). Gould’s petrel is also susceptible to becoming entangled in the sticky fruits of the bird-lime tree (Pisonia umbellifera), which is of particular concern on Cabbage Tree Island. The fruits drop from mature trees during the breeding season and stick to the feathers, preventing flight and consequently leading to starvation (2) (3) (4) (5). 

Furthermore, increasing levels of recreational activity close to areas supporting breeding populations of Gould’s petrel pose a future risk, with additional new threats from introduced species, noise, fire and pollution (4). In New Caledonia there are also worries that rising levels of light pollution could be having an increasingly negative effect on Gould’s petrel, as many are reportedly attracted to lights and accidentally killed each year (5), possibly as a result of becoming disorientated.

Gould’s petrel has been the subject of intensive conservation action, especially on Cabbage Tree Island in Australia where the population dropped to below 250 breeding pairs during the 1990s. Since then, a number of measures have been taken, including the complete removal of rabbits from Cabbage Tree Island and of the bird-lime tree (Pisonia) from areas of the island used by Gould’s petrel for nesting. A successful translocation of nestlings to the nearby Boondelbah Island was also undertaken (3) (4) (5) (6) (7). Both Cabbage Island and Boondelbah Island are designated as Nature Reserves under the Australian National Parks and Wildlife Act 1979 (4). On New Caledonia, the species is faring less well and it is thought to be in decline, however, an annual campaign to save the Gould’s petrels that are attracted to lights has been implemented, and funding has been granted for a rat control program near to a major breeding colony. Additional measures intended to safeguard Gould’s petrel include continued monitoring of both the Australian and New Caledonian subspecies, identification of new potential breeding sites, and further studies into breeding success, levels of predation and the effects of light pollution on the species (5). 

ARKive is supported by OTEP, a joint programme of funding from the UK FCO and DFID which provides support to address priority environmental issues in the Overseas Territories, and Defra

To find out more about Gould’s petrel, see:

• BirdLife International:
  http://www.birdlife.org/
• National Parks and Wildlife Service - Threatened Species Information:
  http://www.environment.nsw.gov.au/resources/nature/TSprofileGouldsPetrel.pdf
 

To find out information on other seabirds in the Southern Oceans, see:

• Southern Oceans Seabird Study Association Inc:
  http://www.sossa-international.org/index.htm