Bermuda Petrel

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Bermuda Petrel
Bermuda petrel chick

Bermuda petrel chick

Class : Birds (aves)
Order : Tubular noses (Procellariiformes)
Family : Petrels (Procellariidae)
Genre : Hook shearwater ( pterodroma )
Type : Bermuda Petrel
Scientific name
Pterodroma cahow
( Nichols & Mowbray , 1916)

The Bermuda Petrel ( Pterodroma cahow ) as Cahow or Bermuda Shearwater called, is a rare seabird from the kind of gadfly petrel ( Pterodroma ). It used to be widespread all over Bermuda , today its range extends to a few rat-free islands.


The Bermuda petrel reaches a length of 38 centimeters and a wingspan of 89 centimeters. The hood that encloses the eyes and the top are brown-gray. There is a brown collar tape on the neck. The beak is black. The underside is white, the wings are white with black edges. In flight, it is easy to confuse it with the larger petrel .

Way of life

Little is known about the way of life of the Bermuda petrel. It is nocturnal and follows the plankton swarms of the Gulf Stream . The breeding season is from January to June. The clutch consists of a single egg. In the past, eggs were laid in caves in the ground on the beach. But rats have displaced the colonies on small rock islands that are not so ideal for breeding. The young hatch after 51 to 54 days and fledge after 90 to 100 days.


This bird was already known to sailors in the 17th century. When a ship landed in Bermuda in the winter of 1614/15, the almost starved English settlers were able to save their lives by killing the trusting shearwaters. Due to the introduction of mammals to Bermuda and the collection of eggs, this species quickly disappeared. In 1906 the ornithologist Louis L. Mowbray discovered a specimen of the Bermuda petrel and in 1916 the first scientific description by Mowbray and John Treadwell Nichols was based on this specimen. It wasn't until 1951 that six nests were discovered and photographed on Castle Harbor Island. A total of 18 breeding pairs were counted. So this bird species was considered rediscovered after more than 330 years. In 1963 it was one of the rarest birds in the world with a population of only 17 breeding pairs. The use of DDT and other insecticides ensured that only some of the eggs were fertile. After the ban on DDT, the inventory was 90 copies in 1994. But this population was also threatened by competition from other seabirds such as the white-tailed tropical bird, but also by the increase in cyclones. In 2003, Hurricane Fabian destroyed a large part of the breeding population. In 2005 the world population was 250 birds. In 2011, 98 breeding pairs were counted, which raised 56 young birds. In 2012 there were 101 breeding pairs.


  • John H. Sparks : Endangered Wildlife. Delphin paperback in color No. 27, Delphin Verlag Stuttgart / Zurich 1974.
  • F. Vester, AW Diamond, H. Stern, G. Thielcke: Save the bird world. Ravensburger Verlag, 1987.

Web links

Commons : Bermuda Petrel ( Pterodroma cahow )  - Collection of images, videos, and audio files