Birdsong field guide
Bulwer's Petrel
Bulweria bulwerii
A small, slender, all-dark gadfly petrel characterized by its long, wedge-shaped tail and graceful, buoyant flight. It is a highly pelagic species that spends the vast majority of its life over open tropical and subtropical waters.
What it sounds like
A rhythmic, barking series of 'whoo-whoo-whoo' notes, often compared to the sound of a distant small dog or a muffled motorboat engine.
Reference call, compare with what you heard
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Field notes
- The species is named after the Scottish naturalist James Bulwer, who collected the type specimen in Madeira in the early 19th century.
- It displays a distinctive pale diagonal bar on the upperwings, which is created by the light-colored edges of the greater coverts.
- To minimize the risk of predation by gulls and hawks, this petrel is strictly nocturnal when visiting its breeding colonies.
- Unlike many other procellariids, it frequently nests in deep rock crevices or under volcanic boulders rather than excavating long earthen burrows.
- Its diet is specialized toward small squid, fish, and pelagic halobates (sea-striders) captured at the ocean surface, often located by an acute sense of smell.
Habitat
Open pelagic waters; nests on remote, rocky offshore islands and coral atolls.
Range
Widespread across the tropical and subtropical regions of the Atlantic, Pacific, and Indian Oceans.
Similar & commonly confused birds
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