Crow, Hawaiian

Corvus hawaiiensis

phylum: Chordata

class: Aves

order: Passeriformes

family: Corvidae

status: Critically endangered, IUCN Endangered, ESA

range: USA (Hawaii)

Description and biology

The Hawaiian crow, called 'alala in Hawaiian, is a large, dark brown bird with a thick, strong beak. An average adult measures 19 inches (48 centimeters) long. The bird's diet consists mainly of fruit, but also includes insects, rodents, small lizards, and even some small birds. Rats and mongooses are its main predators.

Hawaiian crows build their nests high in ohia (lehua) trees (trees in the myrtle family with bright red flowers and hard wood). They use these same nests year after year. Females lay one to five eggs between March and June.

Habitat and current distribution

The Hawaiian crow prefers to inhabit high-elevation rain forests or dry forests that contain many fruit-producing plants and shrubs. The bird is currently restricted to the western side of the island of Hawaii at elevations between 3,400 and 5,000

feet (1,035 and 1,525 meters). In the early 1990s, biologists (people who study living organisms) counted only 11 Hawaiian crows in the wild. A captive population of 10 exists in the Olinda Endangered Species Breeding Facility on the island of Maui.

History and conservation measures

The Hawaiian crow was found throughout the island of Hawaii until the 1930s. Many factors may have led to the bird's present critically endangered state, including hunting, habitat loss, and poor breeding success.

The Hawaiian crow's population was reduced initially by hunting, which was finally outlawed in 1931. Then, the bird lost much of its original habitat as forests were cut down on the island to create farmland or land suitable for housing. With farms came cattle, goats, and pigs, which eventually began eating the Hawaiian crow's natural food sources. Mongooses and rats, as well as disease, further reduced its numbers.

The most significant factor in the bird's decline, however, has been its naturally low breeding ability. Only about one chick per nest survives infancy in the wild. This problem also occurs in captive breeding programs. At the Olinda facility, only two chicks were born in 1989 and 1990. Without high population numbers in the wild to overcome this problem, the Hawaiian crow will not be able to survive.