Markham's storm petrel
A little-known seabird of the Humboldt Current.
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. 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.
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.
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. Genetic analyses in 2004 and 2017 showed that *Oceanodroma* should be merged into *Hydrobates*, because the only *Hydrobates* species, the European storm
- Scientific name
- Hydrobates markhami
- Family
- Hydrobatidae (northern storm petrels)
- Wingspan
- 49–54 cm (19–21 in)
- Body length
- 21–23 cm (8.3–9.1 in)
- Average weight
- 53 g (1.9 oz)
- IUCN status
- Near threatened
- Estimated population (2019)
- 150,000–180,000 individuals
Lore & Background
Markham's storm petrel was first described by ornithologist Osbert Salvin in 1883 as Cymochorea markhami. The species has a complex taxonomic history: it was once considered the same as Tristram's storm petrel, later placed in the genus Oceanodroma, and then moved to Hydrobates after genetic analyses in 2004 and 2017 showed that Oceanodroma was nested within Hydrobates. A 2017 genetic study found it to be the sister species of the black storm petrel, though this was questioned due to possible misidentification. As of the source, its relationships to other members of its genus remain unclear.
The species is a colonial breeder that nests in natural cavities in salt crusts in northern Chile and Peru. The first colony was only reported in 1993, and more colonies are expected to be discovered. Pairs produce one egg per season, laid on bare ground without nesting material. Parents attend the brood only at night, returning to sea before dawn. The timing of the breeding season varies significantly within and between colonies for unknown reasons. A 2023 study found three well-supported genetic clades reflecting the Paracas, Arica, and Salar Grande colonies.
Reader's Guide
Markham's storm petrel is significant as a seabird endemic to the Humboldt Current, breeding in the extreme environment of the Atacama Desert. Its conservation status as near threatened highlights the pressures on its population: habitat destruction from mining of salt crusts and light pollution from mines and cities. Light pollution is estimated to kill about 20,000 fledglings each year, possibly one third of all fledglings. The species is also important for taxonomic study, as its classification has shifted between genera and its relationships remain debated. The 2019 description of it as 'one of the least known seabirds in the world' underscores the need for further research. Its breeding ecology, shared with Elliot's storm petrel and the ringed storm petrel, and the potential for allochronic speciation due to differences in breeding time, make it a subject of ongoing scientific interest.
Did You Know?
- Ninety-five percent of known colonies are found in the Atacama Desert.
- The first colony was only reported in 1993.
- Light pollution is estimated to kill about 20,000 fledglings each year, possibly one third of all fledglings.
- A 2023 study found three well-supported genetic clades of Markham's storm petrel.
More in Birds of the Pacific Ocean 1-24
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