Bermuda petrel  (Pterodroma cahow)

Bermuda was once known as the Isles of the Devils, named by frightened sailors after hearing the haunting nocturnal mating calls of the Bermuda petrel (4). This gadfly petrel has a brownish-black crown and nape, long, brownish-grey upperwings and tail, and white underwings edged with black on the underside. The bill is black and the legs are pink (2).

The Bermuda petrel was once abundant throughout the islands of Bermuda, with numbers as high as 500,000 individuals. It is now present in very low numbers (approximately 180 individuals) on the smaller islands of Bermuda during the breeding season and further north along the western side of the Gulf Stream during the non-breeding season. It has been seen off the coast of North Carolina, USA, as well as in the Azores (2).

Previously an inhabitant of large islands, the Bermuda petrel used to burrow into soft soil to nest. Having been driven to local extinction on these islands by introduced mammals, it has been forced to nest in crevices on smaller islets as the soil is not deep enough to burrow into (5). It ranges widely over the ocean when feeding (5).

Courting and breeding between late October and mid June, the nocturnal Bermuda petrel courts at night whilst flying, screeching eerily. The female lays her eggs in either an artificial burrow or a natural crevice in January and chicks hatch in late February and early March. The hatchlings learn to fly quickly, but do not fledge until late May and early June (5).

The Bermuda petrel eats small squid, shrimp and small fish (5).

The Bermuda petrel was thought to be extinct for nearly 300 years, following the catastrophic effects of introducing pigs, dogs, rats and cats to the islands during the 1500s and 1600s (6). It had also been hunted and much of its habitat has been lost (2). It was rediscovered in the early 1900s and although it is recovering, the population increase is slowed by competition for nest sites from white-tailed tropicbirds, Phaethon lepturus. Other threats are diverse, including light pollution from an airport and a NASA tracking station hindering the courtship flight of the Bermuda petrel, which takes place at night, as well as consistent sea-level rise and flooding of breeding sites (2).

The rediscovery of the Bermuda petrel prompted concerted conservation efforts for this species and since 1961 breeding sites have been managed and artificial burrows created. Regular rat control and removal of white-tailed tropicbirds from nest sites are ongoing. The Bermuda Conservation Programme has reforested previous breeding islands with native plants in the hope of attracting nesting Bermuda petrels. It occurs on Castle Harbour Islands which are a National Park and it will soon be introduced to Nonsuch Island Living Museum in the hope of establishing a breeding colony (2).

For further information on this species see the Cahow Conservation Reports from the Bermuda Audubon Society:
http://www.audubon.bm

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk