The Hawaiian petrel or ''uau'' (''Pterodroma sandwichensis'') is a large, dark grey-brown and white
petrel
Petrels are tube-nosed seabirds in the bird order Procellariiformes.
Description
The common name does not indicate relationship beyond that point, as "petrels" occur in three of the four families within that group (all except the albatross f ...
that 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 elsew ...
to
Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...
.
Distribution
The Hawaiian petrel was formerly found on all the main
Hawaiian Islands
The Hawaiian Islands ( haw, Nā Mokupuni o Hawai‘i) are an archipelago of eight major islands, several atolls, and numerous smaller islets in the North Pacific Ocean, extending some from the island of Hawaii in the south to northernmost Kur ...
except
Niihau
Niihau ( Hawaiian: ), anglicized as Niihau ( ), is the westernmost main and seventh largest inhabited island in Hawaii. It is southwest of Kauaʻi across the Kaulakahi Channel. Its area is . Several intermittent playa lakes provide wetland hab ...
, but today it is mostly restricted to
Haleakalā
Haleakalā (; Hawaiian: ), or the East Maui Volcano, is a massive shield volcano that forms more than 75% of the Hawaiian Island of Maui. The western 25% of the island is formed by another volcano, Mauna Kahalawai, also referred to as the West ...
crater on
Maui
The island of Maui (; Hawaiian: ) is the second-largest of the islands of the state of Hawaii at 727.2 square miles (1,883 km2) and is the 17th largest island in the United States. Maui is the largest of Maui County's four islands, which ...
; smaller populations exist on
Mauna Loa
Mauna Loa ( or ; Hawaiian: ; en, Long Mountain) is one of five volcanoes that form the Island of Hawaii in the U.S. state of Hawaii in the Pacific Ocean. The largest subaerial volcano (as opposed to subaqueous volcanoes) in both mass and ...
on the island of
Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...
,
Waimea Canyon
Waimea Canyon, also known as the Grand Canyon of the Pacific, is a large canyon, approximately ten miles (16 km) long and up to 3,000 feet (900 m) deep, located on the western side of Kauai in the Hawaiian Islands of the United States. ...
on the island of
Kauai
Kauai, () anglicized as Kauai ( ), is geologically the second-oldest of the main Hawaiian Islands (after Niʻihau). With an area of 562.3 square miles (1,456.4 km2), it is the fourth-largest of these islands and the 21st largest island ...
, Lānaihale on
Lānai, and possibly
Molokai
Molokai , or Molokai (), is the fifth most populated of the eight major islands that make up the Hawaiian Islands, Hawaiian Islands archipelago in the middle of the Pacific Ocean. It is 38 by 10 miles (61 by 16 km) at its greatest length an ...
.
It is also reportedly seen on the
Galapagos Islands.
Behavior
Feeding
Their diet consists of 50–75%
squid
True squid are molluscs with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fitting t ...
, and smaller percentages of
fish
Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...
and
crustacean
Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...
s.
Breeding
The birds nest in
burrows or rock crevices. The breeding extends from March to October. The female lays one white egg. When the chick hatches, the parents go out to sea and feed during the day, and return only at night. They pass their food on to the chicks by means of regurgitation. The chicks are charcoal-gray colored and were considered a delicacy by early Hawaiians. Scientists previously thought that the petrels remained relatively close to shore during the breeding season. New research employing microwave
telemetry
Telemetry is the in situ data collection, collection of measurements or other data at remote points and their automatic data transmission, transmission to receiving equipment (telecommunication) for monitoring. The word is derived from the Gr ...
shows that the birds travel as far as
Alaska
Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...
and
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
during two-week-long feeding trips.
When returning to nest burrows at night, adults make a distinctive moaning "oo-ah-oo". At their burrows, adult birds also make a variety of yaps, barks, and squeals. The petrel's flight is characterized by high, steeply banked arcs and glides. Their wings are long and narrow with a wingspan of . The wings and tail are sooty-colored. Their feet are bicolored pink and black.
Status and conservation
The Hawaiian petrel is an endangered species. In addition to loss of habitat from development, the greatest threats to the petrel are
feral cat
A feral cat or a stray cat is an unowned domestic cat (''Felis catus'') that lives outdoors and avoids human contact: it does not allow itself to be handled or touched, and usually remains hidden from humans. Feral cats may breed over dozens ...
s,
small Asian mongoose Small Asian mongoose is a common name applied to two mammals which were formerly considered to be a single species:
* Javan mongoose
*Small Indian mongoose
The small Indian mongoose (''Urva auropunctata'') is a mongoose species native to Iraq an ...
s, and
rat
Rats are various medium-sized, long-tailed rodents. Species of rats are found throughout the order Rodentia, but stereotypical rats are found in the genus ''Rattus''. Other rat genera include ''Neotoma'' ( pack rats), ''Bandicota'' (bandicoot ...
s, all of which feed on the helpless chicks when they are inside their burrows. In
Haleakalā National Park
Haleakalā National Park is an American national park located on the island of Maui in the state of Hawaii. Named after Haleakalā, a dormant volcano within its boundaries, the park covers an area of , of which is a wilderness area. The land wa ...
, great efforts are being made to reduce the number of feral animals, to preserve not only the Hawaiian petrel, but also many other rare Hawaiian birds that fall victim to predation. Wires injure the rare petrels and city lights disorient them, contributing to their decline. The Hawaiian petrel was once considered conspecific with the
dark-rumped petrel of the
Galápagos islands, but was recently split to its own species.
At the recommendation of federal wildlife officials, Hawaii switched to digital television on 15 January 2009, a month ahead of the nationwide FCC mandatory conversion, in order to preserve the nesting season of the uau. Biologists didn't have an accurate count of how many of the species remained, but estimated fewer than 1,000 nested on Haleakalā volcano, their primary nesting area. The earlier digital conversion allowed nearby analog transmission towers to be destroyed without disrupting the nesting season, which begins in February.
See also
*
Dark-rumped petrel
References
*(2005). ''Hawaii's Birds''. Hawaii Audubon Society. Sixth ed.
External links
*BirdLife International. (2005). Species factsheet: Pterodroma sandwichensis. Downloaded fro
BirdLife Internationalon Nov. 3, 2005.
*Oikonos. (September 2007). New Project: The Mystery of the Uau
Haleakalā National Park*
{{Taxonbar, from=Q524533
Pterodroma
Biota of Kauai
Biota of Maui
Endemic birds of Hawaii
Birds described in 1884
ESA endangered species
Taxa named by Robert Ridgway