Newell's shearwater or Hawaiian shearwater (''ʻaʻo''), (''Puffinus newelli'') is a
seabird
Seabirds (also known as marine birds) 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 enviro ...
in the family
Procellariidae
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 (or tubenoses), which als ...
. It belongs to a confusing group of
shearwater
Shearwaters are medium-sized long-winged seabirds in the petrel family Procellariidae. They have a global marine distribution, but are most common in temperate and cold waters, and are pelagic outside the breeding season.
Description
These tub ...
s which are difficult to identify and whose classification is controversial. It was formerly treated as a
subspecies of the
Manx shearwater (''Puffinus puffinus'') and is now often placed in
Townsend's shearwater
Townsend's shearwater (''Puffinus auricularis'') is a rare seabird of the tropics from the family Procellariidae.
Taxonomy
Its relationships are unresolved. Its closest relatives are probably, but not certainly, the Hawaiian shearwater (''Puffi ...
(''Puffinus auricularis''). It is
endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...
to the
Hawaiian Islands.
Description
It is a fairly small shearwater, in length. The wing is long and the tail is . The bird weighs . The upperparts are black with a brown tinge while the underparts are white. The dark colouration on the face extends below the eye and is sharply separated from the white throat. There is a white patch on the flanks, extending onto the sides of the rump. The underwings are mainly white with a dark border. The undertail-coverts have a black and white pattern and appear white in the field. The bill is dark grey or brown and the legs and feet are mainly pale pink. The bird flies low over the water on stiff wings with a mixture of short glides and periods of rapid flapping. It utters a
donkey-like braying call around the breeding areas.
Townsend's shearwater
Townsend's shearwater (''Puffinus auricularis'') is a rare seabird of the tropics from the family Procellariidae.
Taxonomy
Its relationships are unresolved. Its closest relatives are probably, but not certainly, the Hawaiian shearwater (''Puffi ...
(''P. auricularis'') is very similar but has dark undertail-coverts, a shorter tail and a less sharp boundary between the black and white on the face.
Systematics
It was described as a new species ''Puffinus newelli'' in 1900 by the American ornithologist
Henry Wetherbee Henshaw
Henry Wetherbee Henshaw (March 3, 1850 – August 1, 1930) was an American ornithologist and ethnologist. He worked at the U.S. Bureau of Ethnology from 1888 to 1892 and was editor of the journal ''American Anthropologist''.
Biography
Early l ...
using specimens obtained by Brother Matthias Newell from residents of Maui. It was later included by some authors in the Manx shearwater (''Puffinus puffinus'') as was Townsend's shearwater (''Puffinus auricularis''). Later, Townsends's shearwater was raised back to species status with Newell's shearwater as a subspecies of it. This taxonomy was followed by the
American Ornithologists' Union from the sixth edition of its checklist onwards.
However Newell's differs from Townsend's shearwater in various measurements and has a different breeding season and marine habitat. It is now often treated as a separate species, e.g. by BirdLife International following Brooke (2004).
[BirdLife International (2007)] In 2004, a study of
mitochondrial DNA sequences suggested a close relationship between
Rapa shearwater (''Puffinus myrtae'') and Newell's shearwater and the authors proposed that Rapa shearwater be treated as a subspecies of ''P. newelli'' pending further study. The Rapa shearwater is now treated as a full species.
Distribution
It breeds in at least 20 colonies on mountain slopes in the
Hawaiian Islands. The main colonies are on
Kauai, on slopes around the
Alakai Plateau and probably in the
Mokolea Mountains. Its distribution on the other islands is uncertain but it is known to breed on
Molokai and the
island of Hawaii
Hawaii ( ; haw, Hawaii ) is the largest island in the United States, located in the state of Hawaii. It is the southeasternmost of the Hawaiian Islands, a chain of volcanic islands in the North Pacific Ocean. With an area of , it has 63% of th ...
and may breed on
Oahu
Oahu () ( Hawaiian: ''Oʻahu'' ()), also known as "The Gathering Place", is the third-largest of the Hawaiian Islands. It is home to roughly one million people—over two-thirds of the population of the U.S. state of Hawaii. The island of O ...
,
Maui and
Lānai. From April to November it can be seen in the waters around the Hawaiian Islands, particularly around Kauai. Outside the breeding season it disperses into the tropical
Pacific Ocean
The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contin ...
. Its distribution at sea is little known but many move south and east into the waters of the
Equatorial Counter Current
The Equatorial Counter Current is an eastward flowing, wind-driven current which extends to depths of in the Atlantic, Indian, and Pacific Oceans. More often called the North Equatorial Countercurrent (NECC), this current flows west-to-east at ...
. It has been recorded as far west as the
Mariana Islands. In the south there are records from
Samoa
Samoa, officially the Independent State of Samoa; sm, Sāmoa, and until 1997 known as Western Samoa, is a Polynesian island country consisting of two main islands ( Savai'i and Upolu); two smaller, inhabited islands ( Manono and Apolima); ...
in September 1977 and
American Samoa
American Samoa ( sm, Amerika Sāmoa, ; also ' or ') is an unincorporated territory of the United States located in the South Pacific Ocean, southeast of the island country of Samoa. Its location is centered on . It is east of the Internationa ...
in January 1993.
Behaviour
Feeding
It feeds far from land, in areas of deep water (at least 2000 meters). Its diet is little known but includes
squid and small fish. It dives into the water to catch its prey, swimming down to a depth of up to 10 meters using its wings to move forward. It is attracted to schools of
tuna
A tuna is a saltwater fish that belongs to the tribe Thunnini, a subgrouping of the Scombridae ( mackerel) family. The Thunnini comprise 15 species across five genera, the sizes of which vary greatly, ranging from the bullet tuna (max len ...
and gathers in flocks with other seabird species to catch prey driven to the surface by the tuna.
Reproduction
By 1908, it was thought to be
extinct but was rediscovered in 1947 and found breeding on
Kauai in 1967. The nest site is a
burrow dug into a steep slope, usually sheltered by ''uluhe'' (''
Dicranopteris linearis
''Dicranopteris linearis'' is a common species of fern known by many common names, including Old World forked fern, ''uluhe'' ( Hawaiian), and ''dilim'' ( Filipino). It is one of the most widely distributed ferns of the wet Old World tropics and ...
''
fern
A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes exce ...
s). A single white
egg
An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the a ...
is laid during the first two weeks of June. Both parents
incubate the egg and an incubation period of 62 days has been recorded. The young birds leave the nest in October, 88–100 days after hatching. They fly out to sea and are no longer dependent on their parents.
Conservation
It was formerly a much more common bird with a wider breeding distribution in the islands. It has declined due to
habitat loss
Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...
and predation by
introduced species
An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived ther ...
such as
mongoose
A mongoose is a small terrestrial carnivorous mammal belonging to the family Herpestidae. This family is currently split into two subfamilies, the Herpestinae and the Mungotinae. The Herpestinae comprises 23 living species that are native to so ...
s,
rats, cats and
barn owls.
Young birds in particular are attracted to the lights of urban areas at night and many die in collisions with power lines and buildings. The population was estimated at 84,000 birds in the mid-1990s. A severe decline has occurred in recent years which may be associated with the effects of
Hurricane Iniki
Hurricane Iniki ( ; Hawaiian: ''iniki'' meaning "strong and piercing wind") was the most powerful hurricane to strike Hawaii in recorded history. Forming on September 5, 1992, during the strong 1990–1995 El Niño, Iniki was one of eleven Cent ...
in 1992.
Footnotes
References
*Ainley, D. G., T. C. Telfer, and M. H. Reynolds (1997)
Townsend’s and Newell’s Shearwater (''Puffinus auricularis'').In The Birds of North America, No. 297 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists’ Union, Washington, D.C. Accessed 20/09/07.
ubscription required*Austin, Jeremy J., Bretagnolle, Vincent & Pasquet, Eric (2004)
A global molecular phylogeny of the small ''Puffinus'' shearwaters and implications for systematics of the Little-Audubon's Shearwater complex. ''Auk'', 121(3):847-864.
*Beolens, Bo & Watkins, Michael (2003). ''Whose Bird?: Men and women commemorated in the common names of birds'', Christopher Helm, London.
*BirdLife International (BLI) (2007)
Downloaded from http://www.birdlife.org on 20/9/2007
*Melgar, Christian (2002
Accessed 20/09/07.
*Murphy, Robert Cushman (1952)
The Manx Shearwater, ''Puffinus puffinus'', as a species of world-wide distribution.''American Museum Novitates'', 1586:1-21.
*Pratt, H. Douglas; Bruner, Philip L. & Berrett, Delwyn G. (1987). ''A Field Guide to the Birds of Hawaii and the Tropical Pacific'', Princeton University Press, Chichester.
*The Ornithological Society of Polynesia
Accessed 20/09/07.
*
Watling, Dick (2001) ''A Guide to the Birds of Fiji & Western Polynesia'', Environmental Consultants (Fiji), Suva.
{{Taxonbar, from=Q3131786
Puffinus
Endemic birds of Hawaii
Biota of Kauai
Endangered fauna of Hawaii
Birds described in 1900
Taxa named by Henry Henshaw