Tristram's Storm Petrel

The Tristram's storm petrel, or ʻakihikeʻehiʻale, is a seabird of the storm petrel family Hydrobatidae, named in honor of the English clergyman and naturalist Henry Baker Tristram. It is a species cloaked in dark plumage, with a slightly paler rump and a subtle grey bar on the upper wing. This bird is distinguished by its long, angular wings and robust bill, adapted for its diet of small cephalopods. It is the largest member of its family, measuring 24.5 to 27 cm in length, with a wingspan of 54 to 57 cm, and weighing between 71 to 120 grams.

Identification Tips

When identifying Tristram's storm petrel, look for its all-over dark plumage, contrasted by a pale rump and a grey bar on the upper wing. Its long, angular wings and stout bill are also key characteristics. The bird's size, being the largest in its family, can also aid in identification.

Habitat

Tristram's storm petrel is a pelagic bird, spending much of its life at sea. It is found predominantly in the tropical seas of the north Pacific Ocean.

Distribution

The species has a wide distribution across the north Pacific, with breeding colonies located in the Northwest Hawaiian Islands and several small islands south of Japan, including the Bonin Islands and Izu.

Behaviour

This storm petrel is a colonial nester, with colonies attended nocturnally. It is a pelagic feeder, foraging for squid and fish in the open ocean. Breeding occurs during the winter months.

Breeding

Tristram's storm petrel breeds in colonies during the winter. The colonies are located on remote islands and are visited by the birds at night.

Diet and Feeding

The diet of Tristram's storm petrel consists of small cephalopods, squid, and fish, which it captures from the ocean's surface.

Conservation status

The IUCN Red List classifies Tristram's storm petrel as Least Concern. However, the species is considered near threatened due to past declines caused by introduced rats on Torishima Island. Breeding colonies in Hawaii are protected areas, which aids in the species' conservation.