Herald petrels are also known as Trinidade petrels. The subspecies are sometimes considered separate species and the Indian Ocean population has not been thoroughly assessed and may be a different species. Some authorities recognize 3 species instead of 1: Pterodroma atrata, nesting in the Pitcairn Islands in the south Pacific, Pterodroma arminjoniana in the south Atlantic, and Pterodroma heraldica in the south Pacific. Round Island populations may also be a different species, based on significant variation in mitochondrial DNA and information on morphology and parasitic lice faunas.
Pterodroma arminjoniana is named for an Italian vice-admiral, V.F. Arminjoni.
Herald petrels are vocal, using calls described as "ki"s, repeated every 10 to 12 seconds.
Communication Channels: acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
Herald petrel subspecies have been assessed separately by the IUCN. Pterodroma a. arminjoniana (called Trinidade petrels) is considered vulnerable because populations are limited to several small island groups for breeding and are susceptible to threats to those colonies, such as non-native predators, oil spills, and stochastic events. The Round Island populations are also considered threatened by the Commonwealth environmental law in Australia. Pterodroma a. heraldica has a wider breeding range and is considered "least concern." Many breeding colonies are now protected and non-native predators and grazers on some islands have been eradicated, resulting in improved nesting habitat.
US Migratory Bird Act: no special status
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: vulnerable
There are no negative effects of herald petrels on humans.
Herald petrels are important members of their oceanic avian community. Guano from their nesting colonies may be collected for sale.
It can be assumed that herald petrels are an important part of the pelagic seabird fauna, they seem to associate with Puffinus pacificus.
Mutualist Species:
The food habits of herald petrels have not been reported, although they have been observed eating squid and may eat primarily squid. They seem to associate with Puffinus pacificus.
Animal Foods: mollusks
Primary Diet: carnivore (Molluscivore )
Herald petrels are found in several, disjunct regions. The subspecies P. a. arminjoniana occurs in the south Atlantic near Trinidade and Martin Vaz Islands and in the Indian Ocean at Round Island in Mauritius. Some authorities do not place the Round Island populations in this subspecies, however. The subspecies P. a. heraldica is found in the southern Pacific, from northeastern Australia and throughout the tropical Pacific to Eastern Island.
Biogeographic Regions: indian ocean (Native ); atlantic ocean (Native ); pacific ocean (Native )
Herald petrels are found in the open ocean, only coming near or to land during breeding season near breeding colonies. They breed on oceanic islands or "stacks," on rocky cliffs or ledges up to 1000 meters high. They nest sometimes in dense vegetation on these islands.
Habitat Regions: tropical ; saltwater or marine
Aquatic Biomes: pelagic
There is no information on lifespan in herald petrels. Other petrel species (Pterodroma) can live up to 20 years, herald petrels are probably similar.
Herald petrels are from 35 to 39 cm long, about 318 g, and with wingspans of 88 to 102 cm. This species exhibits color polymorphism, with dark, light, and intermediate forms. Color morphs are similar in appearance to Kermadec petrels (Pterodroma neglecta), but with a pointed tail and more white on the underwing. Light morphs are similar to mottled petrels (Pterodroma inexpectata) because the patterns on their underwings form a loose, dark "M" shape of black patterns against a light underwing. Light morphs have less white on their faces than other Pterodroma species with white faces. Juveniles are similar to adults in appearance. They have pink legs and feet, with black distal portions to the feet, but the legs and feet may be entirely black in dark morphs. Their bills are black. Western south Atlantic populations (Trinidade petresl, P. a. arminjoniana) and Round Island petrels are larger than Pacific forms (P. a. heraldi).
Average mass: 318 g.
Range length: 35 to 39 cm.
Range wingspan: 88 to 102 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry ; polymorphic
Sexual Dimorphism: sexes alike
Herald petrels are preyed on at nesting colonies by non-native mammalian predators, including feral pigs (Sus scrofa) and cats (Felis catus). They may have bred at lower elevations before being excluded to higher elevations and less accessible areas by these non-native predators. Feral pigs and goats (Capra hirca) have also destroyed vegetation on nesting islands, further restricting nesting opportunities.
Known Predators:
Mated herald petrels cooperate to raise their young, remaining together for at least a breeding season. Otherwise, there is little know about mating systems in herald petrels.
Mating System: monogamous
Breeding season in herald petrels varies substantially across their range. They form loose colonies that are visited throughout the year by adults. Some breeding may occur throughout the year, with peak laying activity in October and April. They nest on the ground or in crevices under rocks. Females lay 1 egg that is incubated for 53 days. Young are fledged at about 100 days old.
Breeding interval: Some breeding may occur throughout the year, with peak laying activity in October and April.
Breeding season: Breeding season varies across their range.
Range eggs per season: 1 to 1.
Average time to hatching: 53 days.
Average fledging age: 100 days.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
Both parents incubate the egg and feed the young. They alternate incubation shifts of about 8 to 9 days long. Hatchlings are fed most frequently in their first 10 days, then less frequently through 75 days old, and much less frequently after that. Young are fed up to 138 grams of regurgitate at a feeding.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female)
The Trindade petrel (Pterodroma arminjoniana) is a species of seabird and a member of the gadfly petrels. The bird is 35–39 cm (14–15 in) in size, with an 88–102 cm (35–40 in) wingspan.
The petrel has various color morphs: dark and light, as well as intermediates between the two. Previously, two separate populations were considered conspecific, one occurring in the south Pacific, sometimes seen in Hawaii; the other occurring in the south Atlantic, nesting off Brazil, with regular sightings in the Gulf Stream off the southeastern United States. The little-known Pacific birds were then split and determined distinct as the Herald petrel, Pterodroma heraldica. It uses oceanic islands and atolls, nesting on cliff ledges, ridges or rocky slopes. On some islands, nesting birds are threatened by feral cats and rats.
Due to ongoing habitat loss and small breeding range, this species is evaluated as vulnerable on the IUCN Red List of Threatened Species.
The specific name is after Vittorio Arminjon, captain of the ship during the voyage in which the specimen was collected.
The Trindade petrel (Pterodroma arminjoniana) is a species of seabird and a member of the gadfly petrels. The bird is 35–39 cm (14–15 in) in size, with an 88–102 cm (35–40 in) wingspan.
The petrel has various color morphs: dark and light, as well as intermediates between the two. Previously, two separate populations were considered conspecific, one occurring in the south Pacific, sometimes seen in Hawaii; the other occurring in the south Atlantic, nesting off Brazil, with regular sightings in the Gulf Stream off the southeastern United States. The little-known Pacific birds were then split and determined distinct as the Herald petrel, Pterodroma heraldica. It uses oceanic islands and atolls, nesting on cliff ledges, ridges or rocky slopes. On some islands, nesting birds are threatened by feral cats and rats.
Due to ongoing habitat loss and small breeding range, this species is evaluated as vulnerable on the IUCN Red List of Threatened Species.
The specific name is after Vittorio Arminjon, captain of the ship during the voyage in which the specimen was collected.
