Markham's storm petrel

Markham's storm petrel (Hydrobates markhami) is a seabird that lives in the Pacific Ocean off the coasts of Peru, Chile, and Ecuador. The species was named for British explorer Albert Hastings Markham, who collected the specimen that led to its scientific description.

Description

It is a large, slender storm petrel with a wingspan of 49 to 54 cm (19 to 21 in). Its feathers are black to sooty brown, with a grayish bar running diagonally across the upper wing. It belongs to the family Hydrobatidae, the northern storm petrels, and closely resembles the black storm petrel (Hydrobates melania), making the two hard to tell apart.

Distribution and habitat

This bird breeds in colonies, nesting in natural cavities within salt crusts in northern Chile and Peru. Ninety-five percent of known colonies are in the Atacama Desert. The first colony was only reported in 1993, and researchers expect more remain undiscovered. Each pair lays a single egg per season on bare ground, without any nesting material.

Parents attend the brood only at night, returning to the sea before dawn. The timing of the breeding season varies widely, both within and between colonies, for reasons not yet understood. Its diet includes fish, cephalopods like octopuses, and crustaceans; about ten percent of stomach contents come from scavenging.

The International Union for Conservation of Nature (IUCN) lists the species as near threatened. Although its population was estimated at 150,000 to 180,000 individuals in 2019, numbers are declining. The main threats are habitat destruction from mining the salt crusts used for breeding, and light pollution from mines and cities near colonies. Light pollution can attract or disorient fledglings on their first flight to the sea, killing an estimated 20,000 each year—possibly a third of all fledglings.

Taxonomy

Ornithologist Osbert Salvin first described the species as Cymochorea markhami in 1883. In 1931, James L. Peters considered it the same as Tristram's storm petrel (Oceanodroma tristrami), but later work separated them based on tarsus length. For many years, it was placed in the genus Oceanodroma. In 1972, Reginald Wagstaffe treated Tristram's storm petrel as a subspecies of Markham's, though later research recognized them as distinct species.