The Bermuda petrel is a gadfly petrel. Commonly known in Bermuda as the cahow, a name derived from its eerie cries, this nocturnal ground-nesting seabird is the national bird of Bermuda and is pictured on Bermudian currency. Bermuda petrels are the second rarest seabird on the planet. They have medium-sized bodies and long wings, a greyish-black crown and collar, dark grey upper-wings and tail, white upper-tail coverts and white under-wings edged with black, and the underparts are completely white.
Region
North Atlantic Ocean
Typical Environment
Breeds exclusively on small limestone islets around Castle Harbour, Bermuda, nesting in burrows or artificial cavities. Outside the breeding season it disperses widely across the subtropical and temperate North Atlantic, frequenting waters influenced by the Gulf Stream and the Sargasso Sea. At sea it is strictly pelagic, coming to land only to breed. It prefers open ocean with productive convergence zones and frontal systems.
Altitude Range
Sea level to 60 m
Climate Zone
Subtropical
Ease of Keeping
Beginner friendly: 1/5
Also called the cahow, the Bermuda petrel was thought extinct for over three centuries until its dramatic rediscovery in 1951. Intensive conservation—including predator control, artificial burrows, and chick translocation to Nonsuch Island—has led to a steady recovery. It remains one of the world’s rarest seabirds and breeds only on tiny islets in Bermuda. Nocturnal at colonies, its haunting calls gave rise to its local name.
Bermuda petrel chick
Temperament
secretive and nocturnal near colonies; wary at sea
Flight Pattern
soaring glider with shearing arcs and rapid wingbeats
Social Behavior
Forms small, dispersed colonies on predator-managed islets and nests in burrows. Pairs are monogamous and long-lived, laying a single egg per season with shared incubation and chick-rearing. Adults return to colonies at night to avoid predation and human disturbance.
Migratory Pattern
Seasonal migrant
Song Description
At colonies it gives eerie, wailing cahow calls, moans, and chattering notes during night-time flights. At sea it is mostly silent.
