WatchList Species Account for Hawaiian Hawk (Buteo solitarius)

Qualifies for the list as a Red List Species

Photo: Jack Jeffrey

The Hawaiian Hawk, now found only on the Island of Hawaii, is the only hawk in the Hawaiian Archipelago. It has a dark and a light color morph, roughly equal in abundance. It is found in a wide variety of habitats, from exotic forest and pastureland in the lowlands to native forest as high as 2,700 m. Generally only subadults and juveniles use lowland exotic forests. It nests from 30 m above sea level to 1,700 m, but most successful nesting is in 'ohi'a trees at higher elevations. This species has a varied diet, which includes insects, rodents, introduced game birds, and native and non-native passerines. It also preyed upon young Hawaiian Crows, a species now extinct in the wild. Most common avian prey, however, are Japanese White-Eye and Common Myna.

Degradation of native forest habitat by introduced pigs and other ungulates has been devastating to native Hawaiian plant species, not only reducing their numbers but also facilitating the spread of exotic plants. Hawaiian Hawks show a strong preference for nesting in native 'ohi'a trees and some 80% of nests are found there, but this tree species is almost completely absent on Hawai'i below an elevation of 2,000 feet, due to competition from introduced plants. The bird does also nest, however, in exotic forests and agricultural areas, but native trees were selected 86% of the time. Human disturbance of nesting birds and illegal shooting might be the most important threats facing the hawk, though it is hard to determine how often this takes place. The bird apparently is not susceptible to avian malaria.

Population estimates for Hawaiian Hawk range from 1,600 to 2,700 individuals. It is difficult to assess population trends for this species due to a lack of information on historical numbers, but the population is thought to be stable. It is listed as endangered under the Endangered Species Act and classified as Near Threatened by BirdLife International.