Hawaiian Petrel
Encyclopedia
The Hawaiian Petrel or Uau (Pterodroma sandwichensis) is a large, dark grey-brown and white petrel
that is endemic to Hawaii
.
except Niihau
, but today it is mostly restricted to Haleakalā
crater on Maui
; smaller populations exist on Mauna Loa
on the island of Hawaii
, Waimea Canyon on the island of Kauai
, Lānaihale on Lānai
, and possibly Molokai
.
, and smaller percentages of fish
and crustacean
s.
and Japan
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 36 inches (91.4 cm). The wings and tail are sooty-colored. Their feet are bicolored pink and black.
cat
s, Small Asian Mongooses, and rat
s, all of which feed on the helpless chicks when they are inside their burrows. In Haleakalā National Park
, great efforts are being made to reduce the number of feral animals, so to preserve not only the Hawaiian Petrel, but 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.
Petrel
Petrels are tube-nosed seabirds in the bird order Procellariiformes. The common name does not indicate relationship beyond that point, as "petrels" occur in three of the four families within that group...
that is endemic to Hawaii
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
.
Distribution
The Hawaiian Petrel was formerly found on all the main Hawaiian IslandsHawaiian Islands
The Hawaiian Islands are an archipelago of eight major islands, several atolls, numerous smaller islets, and undersea seamounts in the North Pacific Ocean, extending some 1,500 miles from the island of Hawaii in the south to northernmost Kure Atoll...
except Niihau
Niihau
Niihau or Niihau is the seventh largest of the inhabited Hawaiian Islands in the U.S. state of Hawaii, having an area of . Niihau lies southwest of Kauai across the Kaulakahi Channel. Several intermittent playa lakes provide wetland habitats for the Hawaiian Coot, the Black-winged Stilt, and the...
, but today it is mostly restricted to Haleakalā
Haleakala
Haleakalā , 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 the West Maui Mountains.- History :...
crater on Maui
Maui
The island of Maui is the second-largest of the Hawaiian Islands at and is the 17th largest island in the United States. Maui is part of the state of Hawaii and is the largest of Maui County's four islands, bigger than Lānai, Kahoolawe, and Molokai. In 2010, Maui had a population of 144,444,...
; smaller populations exist on Mauna Loa
Mauna Loa
Mauna Loa is one of five volcanoes that form the Island of Hawaii in the U.S. state of Hawaii in the Pacific Ocean, and the largest on Earth in terms of volume and area covered. It is an active shield volcano, with a volume estimated at approximately , although its peak is about lower than that...
on the island of Hawaii
Hawaii (island)
The Island of Hawaii, also called the Big Island or Hawaii Island , is a volcanic island in the North Pacific Ocean...
, Waimea Canyon on the island of Kauai
Kauai
Kauai or Kauai, known as Tauai in the ancient Kaua'i dialect, is geologically the oldest of the main Hawaiian Islands. With an area of , it is the fourth largest of the main islands in the Hawaiian archipelago, and the 21st largest island in the United States. Known also as the "Garden Isle",...
, Lānaihale on Lānai
Lanai
Lānai or Lanai is the sixth-largest of the Hawaiian Islands. It is also known as the Pineapple Island because of its past as an island-wide pineapple plantation. The only town is Lānai City, a small settlement....
, and possibly Molokai
Molokai
Molokai or Molokai is an island in the Hawaiian archipelago. It is 38 by 10 miles in size with a land area of , making it the fifth largest of the main Hawaiian Islands and the 27th largest island in the United States. It lies east of Oahu across the 25-mile wide Kaiwi Channel and north of...
.
Feeding
Their diet consists of 50–75% squidSquid
Squid are cephalopods of the order Teuthida, which comprises around 300 species. Like all other cephalopods, squid have a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms arranged in pairs and two, usually longer, tentacles...
, and smaller percentages of fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate 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...
and crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
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 shows that the birds travel as far as AlaskaAlaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
and Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
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 36 inches (91.4 cm). 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 feralFeral
A feral organism is one that has changed from being domesticated to being wild or untamed. In the case of plants it is a movement from cultivated to uncultivated or controlled to volunteer. The introduction of feral animals or plants to their non-native regions, like any introduced species, may...
cat
Cat
The cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests...
s, Small Asian Mongooses, and rat
Rat
Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus...
s, all of which feed on the helpless chicks when they are inside their burrows. In Haleakalā National Park
Haleakala National Park
Haleakalā National Park is a United States national park located on the island of Maui in the state of Hawaii. The park covers an area of , of which is a wilderness area...
, great efforts are being made to reduce the number of feral animals, so to preserve not only the Hawaiian Petrel, but 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.
External links
- BirdLife International. (2005). Species factsheet: Pterodroma sandwichensis. Downloaded from BirdLife International on Nov. 3, 2005.
- Oikonos. (September 2007). New Project: The Mystery of the Uau. Oikonos
- Haleakalā National ParkUau or Hawaiian Petrel |work=Hawaii’s Comprehensive Wildlife Conservation Strategy |publisher=State of Hawaii |date=2005-10-01 |accessdate=}}