The Hawaiian hawk or ''io'' (''Buteo solitarius'') is a

raptor Raptor or RAPTOR may refer to: Animals The word "raptor" refers to several groups of bird-like dinosaurs which primarily capture and subdue/kill prey with their talons. * Raptor (bird) or bird of prey, a bird that primarily hunts and feeds on v ...

in the genus '' Buteo''

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 ...

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 ...

, currently restricted to the Big Island. The ''io'' is one of two extant birds of prey that are native to Hawaii, the other being the ''

pueo The pueo (''Asio flammeus sandwichensis'') is a subspecies of the short-eared owl and is endemic to Hawaii. The pueo is one of the more famous of the various physical forms assumed by '' aumākua'' (ancestor spirits) in Hawaiian culture. Pueo in ...

'' (Hawaiian short-eared owl) and

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

evidence indicates that it inhabited the island of Hawaii,

Molokai Molokai , or Molokai (), is the fifth most populated of the eight major islands that make up the Hawaiian Islands archipelago in the middle of the Pacific Ocean. It is 38 by 10 miles (61 by 16 km) at its greatest length and width with a us ...

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 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, whic ...

and

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 islan ...

at one time. Today, it is known to breed only 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 ...

'') trees. The species was protected as an

endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inv ...

in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

, but was delisted in 2020. However, the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

classifies the species as

Near Threatened A near-threatened species is a species which has been categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature as that may be vulnerable to endangerment in the near future, but it does not currently qualify fo ...

Description

The Hawaiian hawk measures approximately in length. The female, which weighs on average, is larger than the male, which averages . 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. During breeding season one of the pair, possibly the female, has a distinctive yellow forecap area just above the upper mandible.

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 egg 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 Fledging is the stage in a flying animal's life between hatching or birth and becoming capable of flight. This term is most frequently applied to birds, but is also used for bats. For altricial birds, those that spend more time in vulnera ...

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. Due to Hawaii having few native land

mammal Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur ...

s (The Hawaiian hoary bat is Hawaii's only native terrestrial mammal), its original diet presumably consisted mainly of smaller birds such as the flightless ducks and rails that once inhabited Hawaii. Today it feeds largely on introduced animals such as rats,

lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia altho ...

s, and game birds, as well as invertebrates such as insects. It will also feed on the Hawaiian crow, a Hawaiian bird which is

extinct in the wild A species that is extinct in the wild (EW) is one that has been categorized by the International Union for Conservation of Nature as known only by living members kept in captivity or as a naturalized population outside its historic range due t ...

. They are opportunistic

predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill t ...

s 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.

In Hawaiian culture

The Hawaiian hawk was one of many birds unleashed in the third period of creation (''wā'') mentioned in the Kumulipo. It was a royal symbol in Hawaiian legend, and it is sometimes called ''iolani'' ("exalted hawk"), which was the name of

Kamehameha IV Kamehameha IV (Alekanetero ʻIolani Kalanikualiholiho Maka o ʻIouli Kūnuiākea o Kūkāʻilimoku; anglicized as Alexander Liholiho) (February 9, 1834 – November 30, 1863), reigned as the fourth monarch of Hawaii under the title ''Ke Aliʻi ...

and the Iolani Palace.

References

External links

BirdLife Species Factsheet.
{{Taxonbar, from=Q1275471 Buteo Endemic birds of Hawaii Birds of prey Birds described in 1848 Taxa named by Titian Peale ESA endangered species