General
Herald Petrel: Medium-sized petrel that has three color morphs: light, intermediate and dark. Dark morph bird is dark gray overall with dark forehead and cap and thin black bill; shows silver-gray to white base on underwing flight feathers. Light morph has white breast and belly and dark gray upperparts. Intermediate forms exist between light and dark morphs. Sexes are similar.
Split into Herald Petrel and Trindade Petrel (not in North America) by the American Ornithologist Union. in 2015.
Range and Habitat
Herald Petrel: These birds prefer water below the Equator but were recorded as far north as North Carolina where it is a rare but regular visitor in late spring to late summer. Breeds on Raine Island and other small cays in the Coral Sea. Mostly pelagic, spends its life at sea coming to nesting grounds only to breed. Prefers warm islands with soils suitable for nesting burrows.
Breeding and Nesting
Herald Petrel: One white egg is laid in a burrow which is excavated or cleaned out by both sexes. For their breeding grounds Herald petrels choose warm islands and do not line burrows with any nest materials. Incubation ranges from 49 to 54 days and is carried out by both parents.
Foraging and Feeding
Herald Petrel: This bird is mostly pelagic and spends the majority of its time at sea where it feeds on squid and crustaceans. When looking for food, it skims water, grabs prey with bill, and ingests while in flight.
Vocalization
Herald petrel: Generally quiet when flying over water, but during breeding times when they fly over the colonies on land, they make a rapidly repeated high-pitched "ki ki ki ki" call. It also makes several squeaky whistles and moaning notes and can produce cooing and chattering tern-like sounds.
Similar Species
Herald Petrel: Sooty Shearwater has broader, more stout body, high forehead, light underwings, shorter tail, and very different flight pattern.