Ashy storm petrel

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Ashy storm petrel
Ashystormpetrel.jpeg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Procellariiformes
Family: Hydrobatidae
Genus: Hydrobates
Species:
H. homochroa
Binomial name
Hydrobates homochroa
(Coues, 1864)
Oceanodroma homochroa map.svg
Synonyms
  • Oceanodroma homochroaCoues, 1864

The ashy storm petrel (Hydrobates homochroa) is a small, scarce seabird of the storm petrel family Hydrobatidae. It breeds colonially on islands off the coasts of California and Mexico, and is one of six species of storm petrel that live and feed in the rich California Current system.

Contents

Taxonomy

The ashy storm petrel was first described by American ornithologist Elliott Coues in 1864. Both its common and scientific name, homochroa, "uniformly colored", from Ancient Greek (h)omoia (όμοια), "alike" + "chroma" (χρώμα) "color", come from its coloration.

It was formerly defined in the genus Oceanodroma before that genus was synonymized with Hydrobates . [2]

Description and ecology

This is a small, uniformly sooty-brown storm petrel with a forked tail, closely resembling the black storm petrel, but it is smaller and has a more fluttering style of flight, with the upstroke only becoming horizontal to the body before beginning the downstroke (other storm petrels in its range have a higher upstroke).

It is a gregarious bird at sea, feeding nocturnally on cephalopods, fish (particularly the deep-sea myctophids, which rise to the sea's surface at night) and euphausiid krill such as Thysanoessa spinifera , which also swarm at the surface. They also attend fishing vessels for the fish oils released when the nets are pulled.

Egg (coll.MHNT) Oceanodroma homochroa MHNT ZOO 2010 11 42 California Naurois.jpg
Egg (coll.MHNT)

Ashy storm petrels nest in rock burrows on offshore islands, returning to the nests at night. The species has a long breeding cycle, laying eggs in May and fledging in October, although timing varies greatly, more so than in most other storm petrels; some pairs may have a chick that is half grown when other pairs are still laying. Like in many other seabirds, pairs show both mate and site fidelity, mating in the same pair with the same mate for many years and nesting at the same burrow, despite the pairs spending their lives out of the breeding season separate from each other, and despite the fact that many individuals might seem to compete for burrows at the nesting colonies. A change in mate is usually associated with a change in nesting site.

The ashy storm petrel is a long-lived bird; a banded individual has lived at least 31 years. [3]

Distribution, status, and threats

Ashy storm petrels breed on 17 islands in the northeast Pacific, principally off the coast of California, but including a few sites off the coast of northwestern Mexico. Half the world's population nests on the Farallon Islands near San Francisco. [1] Other breeding islands include the eight Channel Islands of California and a small population on Mexico's Coronados. Bat Cave, on the north side of Santa Cruz Island in Southern California, has the largest nesting colony for the ashy storm petrel in the world, with over 100 nests. [4] Outside of the breeding season, it is believed to be more widely distributed, foraging on the California Current, but it undertakes no large migration and does not range as far as other species of storm petrels. In the early fall, large flocks can be seen in Monterey Bay. The birds do not range inland any significant distance except when storm-blown; for example, a sighting in San Mateo County, California was considered "unusual" by an experienced naturalist. [5]

The world population is estimated to be around 10,000 birds, 8,000 of them breeders, with the Farallon population having declined by one-third between 1972 and 1992. The ashy storm petrel is designated as a species of conservation concern in California. It is threatened by western gull and burrowing owl predation, illumination from fishing boats, introduced predators such as rats and feral cats, and pollution. Most of the islands were it breeds are covered by some degree of protection.

Global warming could have a profound impact on ashy storm petrels. Future changes to coastal California waters due to global warming could result in warmer, less productive waters, which would mean less food would be available for the petrels. In addition, ocean acidification may result in a decline of crustacean prey species due to the effects that excess CO2 will have on the animals' shells. Sea-level rise will also threaten certain nesting sites that would be located too close to water. [6]

Related Research Articles

<span class="mw-page-title-main">Procellariiformes</span> Order of birds

Procellariiformes is an order of seabirds that comprises four families: the albatrosses, the petrels and shearwaters, and two families of storm petrels. Formerly called Tubinares and still called tubenoses in English, procellariiforms are often referred to collectively as the petrels, a term that has been applied to all members of the order, or more commonly all the families except the albatrosses. They are almost exclusively pelagic, and have a cosmopolitan distribution across the world's oceans, with the highest diversity being around New Zealand.

<span class="mw-page-title-main">Seabird</span> Birds that have adapted to life within the marine environment

Seabirds are birds that are adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations. The first seabirds evolved in the Cretaceous period, and modern seabird families emerged in the Paleogene.

<span class="mw-page-title-main">Northern storm petrel</span> Genus and family of birds

Northern storm petrels are seabirds in the genus Hydrobates in the family Hydrobatidae, part of the order Procellariiformes. The family was once lumped with the similar austral storm petrels in the combined storm petrels, but have been split, as they were not closely related. These smallest of seabirds feed on planktonic crustaceans and small fish picked from the surface, typically while hovering. Their flight is fluttering and sometimes bat-like.

<span class="mw-page-title-main">Procellariidae</span> Family of seabirds which includes petrels, shearweters and prions

The family Procellariidae is a group of seabirds that comprises the fulmarine petrels, the gadfly petrels, the diving petrels, the prions, and the shearwaters. This family is part of the bird order Procellariiformes, which also includes the albatrosses and the storm petrels.

<span class="mw-page-title-main">European storm petrel</span> Migratory seabird in the family Hydrobatidae

The European storm petrel, British storm petrel, or just storm petrel is a seabird in the northern storm petrel family, Hydrobatidae. The small, square-tailed bird is entirely black except for a broad, white rump and a white band on the under wings, and it has a fluttering, bat-like flight. The large majority of the population breeds on islands off the coasts of Europe, with the greatest numbers in the Faroe Islands, United Kingdom, Ireland, and Iceland. The Mediterranean population is a separate subspecies, but is inseparable at sea from its Atlantic relatives; its strongholds are Filfla Island (Malta), Sicily, and the Balearic Islands.

<span class="mw-page-title-main">Leach's storm petrel</span> Species of bird

Leach's storm petrel or Leach's petrel is a small seabird of the tubenose order. It is named after the British zoologist William Elford Leach. The scientific name is derived from Ancient Greek. Hydrobates is from hydōr "water", and batēs "walker", and leucorhous is from leukos, "white" and orrhos, "rump". It was formerly defined in the genus Oceanodroma before that genus was synonymized with Hydrobates.

<span class="mw-page-title-main">Swinhoe's storm petrel</span> Species of bird

Swinhoe's storm petrel or Swinhoe's petrel is a small, all-brown seabird of the storm petrel family Hydrobatidae.

<span class="mw-page-title-main">Band-rumped storm petrel</span> Species of bird

The band-rumped storm petrel, Madeiran storm petrel, or Harcourt's storm petrel is of the storm petrel family Hydrobatidae.

<span class="mw-page-title-main">Ringed storm petrel</span> Species of bird

The ringed storm petrel, also known as Hornby's storm petrel, is a seabird that ranges in the Humboldt Current off the coasts of South America. The species is a very distinctive member of the storm petrel family, with a dark cap, white face and underparts, forked tail and a black band across the chest. It is relatively common in the seas off Peru, Chile and Ecuador. The species is named after Admiral Sir Phipps Hornby.

<span class="mw-page-title-main">Black storm petrel</span> Species of bird

The black storm petrel is a small seabird of the storm petrel family Hydrobatidae. It is 23 cm in length, with a wingspan of 46–51 cm.

<span class="mw-page-title-main">Least storm petrel</span> Species of bird

The least storm petrel is a small seabird of the storm petrel family Hydrobatidae. It is 13–15 cm in length, with a wingspan of 32 cm. It is the smallest member of the order Procellariiformes. It was formerly defined in the genus Oceanodroma before that genus was synonymized with Hydrobates.

<span class="mw-page-title-main">Fork-tailed storm petrel</span> Species of bird

The fork-tailed storm petrel is a small seabird of the storm petrel family Hydrobatidae. It is the second-most abundant and widespread storm petrel and is the only bird in its family that is bluish-grey in colour.

<span class="mw-page-title-main">Bonin petrel</span> Species of bird

The Bonin petrel or nunulu is a seabird in the family Procellariidae. It is a small gadfly petrel that is found in the northwest Pacific Ocean. Its secretive habits, remote breeding colonies and limited range have resulted in few studies and many aspects of the species' biology are poorly known.

<span class="mw-page-title-main">Markham's storm petrel</span> Species of seabird in Pacific South America

Markham's storm petrel is a species of storm petrel in the family Hydrobatidae. An all-black to sooty brown seabird, Markham's storm petrel is difficult to differentiate from the black petrel Procellaria parkinsoni in life, and was once described as conspecific with, or biologically identical to, Tristram's storm petrel Hydrobates tristrami. Markham's storm petrel inhabits open seas in the Pacific Ocean around Peru, Chile, and Ecuador, but only nests in northern Chile and Peru, with ninety-five percent of all known breeding populations in 2019 found in the Atacama Desert. First described by British ornithologist Osbert Salvin in 1883, the bird was named in honor of Albert Hastings Markham, a naval officer who collected a specimen off Peru.

<span class="mw-page-title-main">Tristram's storm petrel</span> Species of bird

Tristram's storm petrel or ʻakihikeʻehiʻale is a species of seabird in the storm petrel family Hydrobatidae. The species' common and scientific name is derived from the English clergyman Henry Baker Tristram; the species can also be known as the sooty storm petrel. Tristram's storm petrel has a distribution across the north Pacific Ocean, predominantly in tropical seas.

<span class="mw-page-title-main">Austral storm petrel</span> Family of birds

Austral storm petrels, or southern storm petrels, are seabirds in the family Oceanitidae, part of the order Procellariiformes. These smallest of seabirds feed on planktonic crustaceans and small fish picked from the surface, typically while hovering. Their flight is fluttering and sometimes bat-like.

<span class="mw-page-title-main">Monteiro's storm petrel</span> Species of bird

Monteiro's storm petrel is a seabird species from the storm petrel family, Hydrobatidae. The cryptic species was once considered to be conspecific with the band-rumped storm petrel. The species is endemic to the Azores.

<span class="mw-page-title-main">Castle Rock National Wildlife Refuge</span> Offshore from Crescent City in northern California

Castle Rock National Wildlife Refuge is 0.5 miles (0.80 km) offshore from Crescent City in northern California. This coastal rock covers approximately 14 acres (57,000 m2), and rises steeply 335 feet (102 m) above sea level. The refuge provides an important sanctuary for the Aleutian cackling goose and nesting seabirds.

<span class="mw-page-title-main">Seabird breeding behavior</span>

The term seabird is used for many families of birds in several orders that spend the majority of their lives at sea. Seabirds make up some, if not all, of the families in the following orders: Procellariiformes, Sphenisciformes, Pelecaniformes, and Charadriiformes. Many seabirds remain at sea for several consecutive years at a time, without ever seeing land. Breeding is the central purpose for seabirds to visit land. The breeding period is usually extremely protracted in many seabirds and may last over a year in some of the larger albatrosses; this is in stark contrast with passerine birds. Seabirds nest in single or mixed-species colonies of varying densities, mainly on offshore islands devoid of terrestrial predators. However, seabirds exhibit many unusual breeding behaviors during all stages of the reproductive cycle that are not extensively reported outside of the primary scientific literature.

<span class="mw-page-title-main">Ainley's storm petrel</span> Species of bird

Ainley's storm petrel is a species of seabird in the family Hydrobatidae. It breeds in the winter on Guadalupe Island off the western coast of Mexico. It ranges south to the Galápagos Islands. It is considered by some authorities to be a subspecies of Leach's storm petrel.

References

  1. 1 2 BirdLife International (2018). "Hydrobates homochroa". IUCN Red List of Threatened Species . 2018: e.T22698562A132653646. doi: 10.2305/IUCN.UK.2018-2.RLTS.T22698562A132653646.en . Retrieved 13 November 2021.
  2. "Taxonomic Updates – IOC World Bird List" . Retrieved 2021-07-29.
  3. United States Geological Survey (USGS) (2006): Patuxent Wildlife Research Center – Grebes, Loons, Alcids, Gulls, Terns, Albatross and other tubenoses, Cormorants and related species, AOU Numbers 001.0–128.0 Longevity Records Archived August 28, 2006, at the Wayback Machine . Version of July, 2006. Retrieved 2006-SEP-4.
  4. "Channel Islands Kayaking Information" (PDF). National Park Service. 2006.
  5. Littlejohn, Chase (1916). "Some unusual records for San Mateo County, California. Abstract in the Minutes of Cooper Club Meetings" (PDF). Condor . 18 (1): 38–40. doi:10.2307/1362896. JSTOR   1362896.
  6. Benstead, Phil, and James Gilroy (2009). Ashy Storm Petrel (Oceanodroma homochroa). BirdLife species factsheet.

Further reading