Bonin petrel

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Bonin petrel
Pterodroma hypoleuca -Midway Atoll, USA-8.jpg
On Midway Atoll
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Procellariiformes
Family: Procellariidae
Genus: Pterodroma
Species:
P. hypoleuca
Binomial name
Pterodroma hypoleuca
(Salvin, 1888)

The Bonin petrel or nunulu [2] (Pterodroma hypoleuca) 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.

Contents

Taxonomy

The Bonin petrel was formally described in 1888 by the English naturalist Osbert Salvin and given the binomial name Oestrelata hypoleuca. He specified the type location as the "Krusenstern Islands" instead of one of the Northwestern Hawaiian Islands. [3] [4] The Bonin petrel is now placed with the other gadfly petrels in the genus Pterodroma that was introduced by French naturalist Charles Lucien Bonaparte in 1856. [5] [6] The genus name combines the Ancient Greek pteron meaning "wing" with dromos meaning "racer" or "runner". The specific epithet hypoleuca is from the Ancient Greek hupi meaning "beneath" with leukos meaning "white". [7] Despite the species having two remote and separate breeding localities the species is monotypic and no subspecies are recognised. [6]

The Bonin petrel is currently thought to be closely related to the mottled petrel and white-necked petrel in the subgenus Proaestrelata, based on a review of the whole genus Pterodroma looking at morphology, calls, breeding biology, diet and parasitic lice. [8]

Description

The Bonin petrel is a small gadfly petrel, 30 cm long with a wingspan of around 67 cm. It has a white head with a black cap and face markings; overall the head often has a scaled appearance. Its pale grey upperparts have darker primaries and wing coverts creating an "M" mark across the back. The underwing is white with dark edging and a patch at the carpal joint and across underwing coverts. The tail is dark grey, and the rest of the plumage is white, except for a dark half collar on the breast. Like the rest of the Pterodroma petrels the black bill is short and hooked. The legs and feet are pink with dark patches.

Distribution and population

Despite the species's name, 995,000 individuals, about 99% of the total population, breed on the Northwestern Hawaiian Islands, while 5,000 individuals (1% of the population) breed off the coast of Japan on the Ogasawara and Volcano Islands.

Behaviour

Diet

The Bonin petrel and the closely related mottled petrel are the only Pterodroma petrels with a fish dominated diet. Principal prey items are fish from the family Myctophidae (lantern fish) and Sternoptychidae (hatchetfish). Squid from the family Ommastrephidae are also consumed. [9] All of these prey are midwater residents that use photophores and migrate to the surface during the night to feed; thus it is assumed that Bonin petrels are nocturnal feeders that seize prey at the surface while resting on the sea or in flight. Bonin petrel eyes contain high levels of the pigment rhodopsin which aids nocturnal vision. The Bonin petrel is usually solitary at sea, but is occasionally seen in large multi-species flocks. Like all procellariids the Bonin petrel has a modified area of the gut known as a proventriculus which partly digests prey to create stomach oil, an energy rich oil which is lighter to carry than prey.

Breeding

A Bonin petrel trapped in the sand on Midway Atoll by the 2011 Tohoku earthquake and tsunami, before being rescued. Midway bonin petrel 2011 tsunami.jpg
A Bonin petrel trapped in the sand on Midway Atoll by the 2011 Tōhoku earthquake and tsunami, before being rescued.

The Bonin petrel breeds in dense colonies, on islands in the Northwestern Hawaiian Islands; French Frigate Shoals, Laysan, Lisianski Island, Pearl and Hermes Reef, Midway Atoll and Kure Atoll; and on the Volcano Islands and Bonin Islands south of Japan. Colonies are only visited by birds at night, with birds usually arriving soon after sunset. [10] Nesting occurs in the winter in order to avoid competition for burrows with other nesting procellariids. In the Northwestern Hawaiian Islands the nesting season sometimes overlaps with the larger wedge-tailed shearwater, which will evict and even kill Bonin petrel chicks in order to use the nesting burrows. Both parents participate in digging burrows, which are usually dug in sand or hard coral substrate, and are between 1 and 3 m long. Pairs are territorial, and will defend an area of around 2 m around the burrow entrance. They also display philopatry, returning to the same burrow in consecutive years, redigging the burrow if it has collapsed. Burrows in harder coral substrate are less likely to collapse than those dug into sand. [10]

Bonin petrel chick Starr 990520-0830 Casuarina equisetifolia.jpg
Bonin petrel chick

The species is thought to mate for life (like other Procellariiformes); pairs undertake mating flights consisting of pairs chasing and calling at each other over the colony prior to laying. A single egg is laid by a pair each breeding season, if it is lost then no attempt is made to re-lay. Laying occurs in late January. Both parents incubate the egg, with incubation stints of eight days for the male and six days for the female. Hatching occurs after around 50 days, around mid-March. The chicks are semi-altricial at hatching, covered in light grey down, and are brooded by the adults for two days after hatching, after which both parents feed at sea and return at night to feed the chick. Chicks are fed stomach oil and small items of prey. Chicks fledge around 80 days after hatching, in early June.

Migration

After the breeding season both chicks and adults migrate northwards to the seas off Honshū and Sanriku in Japan. The timing of the migration is partly influenced by sea surface temperatures. Birds begin to disperse south and east again in August and begin to return to their breeding islands in September. During the breeding season birds feed in the waters surrounding breeding islands. The species has not been recorded in the east Pacific.

Relationship with humans

Prior to the arrival of humans the Bonin petrel nested on the main Hawaiian Islands, fossil remains have been found on Kauai, Oahu and Molokai. These bones have been found in association with human archaeology, strongly implying that they were a food source for Polynesian settlers, along with other seabirds. The species was extirpated from the main islands prior to the arrival of Europeans.

The species is currently threatened by introduced species, particularly rats. [11] Polynesian rats and black rats have devastated populations of Bonin petrels in the Northwestern Hawaiian Islands, primarily by taking eggs. Polynesian rats introduced to Kure Atoll were such a problem for Bonin petrels that for a five-year period in the 1960s not a single chick fledged (hatching success can be as high as 90% in the absence of introduced predators). Similar devastation occurred on Midway, where black rats introduced in 1943 (the same black rats that caused the extinction of the Laysan rail) reduced the population of Bonin petrels from 500,000 birds to 32,000 by 1995. [12] Rabbits introduced to Lisianski Island destroyed nesting habitat and undermined nesting burrows. Habitat destruction limits breeding success on some islands, especially as it increases competition with more aggressive species like the wedge-tailed shearwater.

Conservation measures are in place to protect the Bonin petrel and other seabirds that share the species' breeding islands. Island restoration projects are restoring native vegetation on Laysan and Midway, and rats and rabbits have been removed from all the Northwestern Hawaiian Islands. The species is currently classified as least concern by the IUCN. [1]

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">Gadfly petrel</span> Genus of birds

The gadfly petrels or Pterodroma are a genus of about 35 species of petrels, part of the seabird order Procellariiformes. The gadfly petrels are named for their speedy weaving flight, as if evading gadflies (horseflies). The flight action is also reflected in the name Pterodroma, from Ancient Greek pteron, "wing" and dromos, "runner".

<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">Zino's petrel</span> Small seabird in the gadfly petrel genus

Zino's petrel or the freira, is a species of small seabird in the gadfly petrel genus, endemic to the island of Madeira. This long-winged petrel has a grey back and wings, with a dark "W" marking across the wings, and a grey upper tail. The undersides of the wings are blackish apart from a triangle of white at the front edge near the body, and the belly is white with grey flanks. It is very similar in appearance to the slightly larger Fea's petrel, and separating these two Macaronesian species at sea is very challenging. It was formerly considered to be a subspecies of the soft-plumaged petrel, P. mollis, but they are not closely related, and Zino's was raised to the status of a species because of differences in morphology, calls, breeding behaviour and mitochondrial DNA. It is one of Europe's most endangered seabirds, with breeding areas restricted to a few ledges high in the central mountains of Madeira.

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

The magenta petrel, or Chatham Island tāiko, is a small seabird in the gadfly petrel genus, Pterodroma. Found exclusively on Chatham Island, New Zealand, it is one of the rarest birds in the world, believed to be extinct for over 100 years before its rediscovery in the 1970s.

<span class="mw-page-title-main">Laysan rail</span> Extinct species of bird

The Laysan rail or Laysan crake was a flightless bird endemic to the Northwest Hawaiian Island of Laysan. This small island was and still is an important seabird colony, and sustained a number of endemic species, including the rail. It became extinct due to habitat loss by domestic rabbits, and ultimately World War II.

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

The black-footed albatross is a large seabird of the albatross family Diomedeidae from the North Pacific. All but 2.5% of the population is found among the Northwestern Hawaiian Islands. It is one of three species of albatross that range in the northern hemisphere, nesting on isolated tropical islands. Unlike many albatrosses, it is dark plumaged.

<span class="mw-page-title-main">Laysan finch</span> Species of bird

The Laysan finch is a species of Hawaiian honeycreeper, that is endemic to the Northwestern Hawaiian Islands. It is one of four remaining finch-billed Hawaiian honeycreepers and is closely related to the smaller Nihoa finch. The Laysan finch is named for Laysan, the island to which it was endemic on its discovery. It was subsequently introduced to a few other atolls, and its historical range included some of the main islands.

<span class="mw-page-title-main">Wedge-tailed shearwater</span> Species of bird

The wedge-tailed shearwater is a medium-large shearwater in the seabird family Procellariidae. It is one of the shearwater species that is sometimes referred to as a muttonbird, like the sooty shearwater of New Zealand and the short-tailed shearwater of Australia. It is found throughout the tropical Pacific and Indian Oceans, roughly between latitudes 35°N and 35°S. It breeds on the islands off Japan, on the Islas Revillagigedo, the Hawaiian Islands, the Seychelles, the Northern Mariana Islands, and off Eastern and Western Australia.

<span class="mw-page-title-main">Laysan albatross</span> Species of bird

The Laysan albatross is a large seabird that ranges across the North Pacific. The Northwestern Hawaiian Islands are home to 99.7% of the population. This small gull-like albatross is the second-most common seabird in the Hawaiian Islands, with an estimated population of 1.18 million birds, and is currently expanding its range to new islands. The Laysan albatross was first described as Diomedea immutabilis by Lionel Walter Rothschild, in 1893, on the basis of a specimen from Laysan Island.

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

The Bermuda petrel is a gadfly petrel. Commonly known in Bermuda as the cahow, a name derived from its eerie cries, this nocturnal ground-nesting seabird is the national bird of Bermuda and can be found pictured on Bermudian currency. The Bermuda petrel is the second rarest seabird on the planet. They have medium-sized body and long wings, a greyish-black crown and collar, dark grey upper-wings and tail, white upper-tail coverts and white under-wings edged with black, and the underparts are completely white.

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

The Galápagos petrel is one of the six endemic seabirds of the Galápagos. Its scientific name derives from Ancient Greek: Pterodroma originates from pteron and dromos, meaning "wing" and "runner", and phaeopygia comes from phaios and pugios, meaning "dusky" and "rump". Members of Pterodroma genus are also called the gadfly petrels because their erratic twisting and turning in flight resemble that of gadflies.

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

Barau's petrel is a medium-sized gadfly petrel from the family Procellariidae. Its main breeding site is the island of Réunion in the Indian Ocean.

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

The Trindade petrel 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.

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

Cook's petrel, or the tītī or blue-footed petrel, is a Procellariform seabird. It is a member of the gadfly petrels and part of the subgenus Cookilaria Bonaparte, 1856, which includes the very similar Stejneger's petrel.

The Polynesian storm petrel is a species of seabird in the family Oceanitidae. It is the only species placed in the genus Nesofregetta.Markedly polymorphic, several subspecies were described, and light birds were even considered a species on their own. Subspecies are not generally accepted today.

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

The Juan Fernández petrel is a species of seabird in the family Procellariidae. It nests on a single island off the coast of Chile, in the Juan Fernández Archipelago. It was previously classified as a subspecies of the white-necked petrel, which is found in tropical waters of the Pacific and Indian Oceans.

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

Gould's petrel is a species of seabird in the family Procellariidae. The common name commemorates the English ornithologist and bird artist John Gould (1804–1881).

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

Pycroft's petrel is a species of seabird in the petrel and shearwater family Procellariidae.

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

The Herald petrel is a species of seabird and a member of the gadfly petrels. Its range includes the south Pacific Ocean and Indian Ocean.

References

  1. 1 2 BirdLife International (2018). "Pterodroma hypoleuca". IUCN Red List of Threatened Species . 2018: e.T22697967A132615616. doi: 10.2305/IUCN.UK.2018-2.RLTS.T22697967A132615616.en . Retrieved 12 November 2021.
  2. Gregg, Jason (12 May 2021). "Decolonizing Seabirds". Hakai Magazine. Archived from the original on 2021-05-12. Retrieved 2021-05-14.
  3. Salvin, Osbert (1888). "Critical notes on the Procellariidae". Ibis. 5th Series. 6: 351–360 [359].
  4. Mayr, Ernst; Cottrell, G. William, eds. (1979). Check-List of Birds of the World. Vol. 1 (2nd ed.). Cambridge, Massachusetts: Museum of Comparative Zoology. p. 76.
  5. Bonaparte, Charles Lucien (1856). "Espèces nouvelles d'oiseaux d'Asie et d'Amérique, et tableaux paralléliques des Pélagiens ou Gaviae". Comptes Rendus Hebdomadaires des Séances de l'Académie des Sciences (in French). 42: 764–776 [768].
  6. 1 2 Gill, Frank; Donsker, David; Rasmussen, Pamela, eds. (July 2021). "Petrels, albatrosses". IOC World Bird List Version 11.2. International Ornithologists' Union. Retrieved 4 January 2022.
  7. Jobling, James A. (2010). The Helm Dictionary of Scientific Bird Names. London: Christopher Helm. pp.  199, 322. ISBN   978-1-4081-2501-4.
  8. Imber, M.J. (1985). "Origins, phylogeny and taxonomy of the gadfly petrels Pterodroma spp.". Ibis. 127 (2): 197–229. doi:10.1111/j.1474-919X.1985.tb05055.x.
  9. Harrison, C. S., T. S. Hida, M. P. Seki. (1983). "Hawaiian seabird feeding ecology". Wildl. Monogr.85: 171.
  10. 1 2 Grant, Gilbert; Warham, John; Pettit, Ted; Whittow, Causey (1983). "Reproductive Behavior and Vocalizations of the Bonin Petrel" (PDF). The Wilson Journal. 95 (4): 522–539.
  11. Seto, Nanette; Conant, Sheila (1996). "The Effects of Rat (Rattus rattus) Predation on the Reproductive Success of the Bonin Petrel (Pterodroma hypoleuca) on Midway Atoll". Colonial Waterbirds. 19 (2): 171–185. doi:10.2307/1521854. JSTOR   1521854.
  12. Seto, N. W. H., and D. O’Daniel. 1999. Bonin Petrel (Pterodroma hypoleuca). In The Birds of North America, No. 385 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.