Hawaiian Hawk
Encyclopedia
The Hawaiian Hawk or Io, Buteo solitarius, is a raptor
of the Buteo
genus
endemic to Hawaii
. Buteos tend to be easily recognized by their bulky bodies relative to their overall length and wingspan. The Io is the only hawk that is native to Hawaii, and fossil
evidence indicates that it inhabited the island of Hawaii
, Molokai
, Oahu
, and Kauai
at one time. Today, it is only known to breed on the Big Island in stands of native ōhia lehua (Metrosideros polymorpha
) trees. The species is protected as an endangered species
in the United States
. However, the IUCN classifies the species as Near Threatened
.
but sometimes they could lay up to three in their clutch. The female does the majority of sitting during the 38 days of incubation, while the male does the majority of the hunting. After the egg is hatched, the female only allows the male to visit when delivering food to the nest. The chick fledge
s at seven or eight weeks. Fifty to seventy percent of the nests successfully fledge young.
The Io usually hunts from a stationary position, but can also dive on prey from the air. It feeds on rat
s, small bird
s, stream animals, cricket
s, praying mantises
, millipede
s, centipede
s, and occasionally worms. It will also feed on the Hawaiian Crow
, a Hawaiian bird which is extinct in the wild
. They are opportunistic predators and are versatile in their feeding habits. They have a shrill and high-pitched call much like their Hawaiian name: "eeeh-oh." They are very noisy during the breeding season. Io are strong fliers.
The Hawaiian hawk was a royal symbol in Hawaiian legend, and it is sometimes called “Iolani,” or “Exalted Hawk”, which was the name of Kamehameha IV
and the Iolani Palace.
Bird of prey
Birds of prey are birds that hunt for food primarily on the wing, using their keen senses, especially vision. They are defined as birds that primarily hunt vertebrates, including other birds. Their talons and beaks tend to be relatively large, powerful and adapted for tearing and/or piercing flesh....
of the Buteo
Buteo
Buteo is a genus of medium to fairly large, wide-ranging raptors with a robust body and broad wings. In the Old World, members of this genus are called "buzzards", but "hawk" is used in North America...
genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
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...
. Buteos tend to be easily recognized by their bulky bodies relative to their overall length and wingspan. The Io is the only hawk that is native to Hawaii, and fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
evidence indicates that it inhabited 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...
, 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...
, Oahu
Oahu
Oahu or Oahu , known as "The Gathering Place", is the third largest of the Hawaiian Islands and most populous of the islands in the U.S. state of Hawaii. The state capital Honolulu is located on the southeast coast...
, and 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",...
at one time. Today, it is only known to breed on the Big Island in stands of native ōhia lehua (Metrosideros polymorpha
Metrosideros polymorpha
The ōhia lehua is a species of flowering evergreen tree in the myrtle family, Myrtaceae, that is endemic to the six largest islands of Hawaii. It is a highly variable tree, being tall in favorable situations, and much smaller when growing in boggy soils or on basalt...
) trees. The species is protected as an endangered species
Endangered Species Act
The Endangered Species Act of 1973 is one of the dozens of United States environmental laws passed in the 1970s. Signed into law by President Richard Nixon on December 28, 1973, it was designed to protect critically imperiled species from extinction as a "consequence of economic growth and...
in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. However, the IUCN classifies the species as Near Threatened
Near Threatened
Near Threatened is a conservation status assigned to species or lower taxa that may be considered threatened with extinction in the near future, although it does not currently qualify for the threatened status...
.
Appearance
The Hawaiian Hawk measures approximately 40 to 46 cm (15.7 to 18.1 ) in length. The female is larger than the male. Two color phases exist: a dark phase (dark brown head, breast, and underwings), and a light color phase (dark head, light breast and light underwings). Feet and legs are yellowish in adults and greenish in juveniles.Threats
Common threats to the Io are illegal shootings, the degradation of their native forest habitat, poisoning, vehicle collisions, starvation, and predation from other animals.Lifestyle
This solitary hawk remains in and defends its territories year round. They nest from March through September, and usually lay only one eggEgg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
but sometimes they could lay up to three in their clutch. The female does the majority of sitting during the 38 days of incubation, while the male does the majority of the hunting. After the egg is hatched, the female only allows the male to visit when delivering food to the nest. The chick fledge
Fledge
Fledge is the stage in a young bird's life when the feathers and wing muscles are sufficiently developed for flight. It also describes the act of a chick's parents raising it to a fully grown state...
s at seven or eight weeks. Fifty to seventy percent of the nests successfully fledge young.
The Io usually hunts from a stationary position, but can also dive on prey from the air. It feeds on 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, small bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s, stream animals, cricket
Cricket
Cricket is a bat-and-ball game played between two teams of 11 players on an oval-shaped field, at the centre of which is a rectangular 22-yard long pitch. One team bats, trying to score as many runs as possible while the other team bowls and fields, trying to dismiss the batsmen and thus limit the...
s, praying mantises
Mantis
Mantis is the common name of any insect in the order Mantodea, also commonly known as praying mantises. The word itself means "prophet" in Latin and Greek...
, millipede
Millipede
Millipedes are arthropods that have two pairs of legs per segment . Each segment that has two pairs of legs is a result of two single segments fused together as one...
s, centipede
Centipede
Centipedes are arthropods belonging to the class Chilopoda of the subphylum Myriapoda. They are elongated metameric animals with one pair of legs per body segment. Despite the name, centipedes can have a varying number of legs from under 20 to over 300. Centipedes have an odd number of pairs of...
s, and occasionally worms. It will also feed on the Hawaiian Crow
Hawaiian Crow
The Hawaiian Crow or Alalā is a species of bird in the crow family, Corvidae. It is about the size of the Carrion Crow at in length, but with more rounded wings and a much thicker bill. It has soft, brownish-black plumage and long, bristly throat feathers; the feet, legs and bill are black...
, a Hawaiian bird which is extinct in the wild
Extinct in the Wild
Extinct in the Wild is a conservation status assigned to species or lower taxa, the only known living members of which are being kept in captivity or as a naturalized population outside its historic range.-Examples:...
. They are opportunistic predators and are versatile in their feeding habits. They have a shrill and high-pitched call much like their Hawaiian name: "eeeh-oh." They are very noisy during the breeding season. Io are strong fliers.
The Hawaiian hawk was a royal symbol in Hawaiian legend, and it is sometimes called “Iolani,” or “Exalted Hawk”, which was the name of Kamehameha IV
Kamehameha IV
Kamehameha IV, born Alexander Iolani Liholiho Keawenui , reigned as the fourth king of the Kingdom of Hawaii from January 11, 1855 to November 30, 1863.-Early life:...
and the Iolani Palace.