Endangered Species in the Pacific Islands

Hawaiian Goose / Branta sandvicensis  / Nēnē

This regal goose is Hawai‘i’s state bird. The nēnē measures between 24 to 27 inches in length, has a black head and bill, yellow-buff cheeks, a buff neck with dark furrows, and partially webbed black feet. The reduction of webbing between their toes enables them to walk more easily on the rugged lava flows. Its vocalizations are similar to those of the Canada goose but also gives a low murmuring "nay" or "nay-nay" call.

Nēnē - Photo credit Brenda Zaun/USFWS

Habitat & Behavior:
Nēnē currently frequent scrubland, grassland, golf courses, sparsely vegetated slopes and on Kaua‘i, in open lowland country. The nēnē's vegetarian diet consists of seeds of grasses and herbs as well as leaves, buds, flowers and fruits of various plants. Nēnē do not require standing or flowing water for successful breeding but will use it when available. The current distribution of nēnē has been highly influenced by the location of release sites of captive-bred nēnē.

The breeding season is from August to April. Their nests are down-lined and usually well concealed under bushes. Nēnē seem to prefer nesting in the same nest area year after year. One to six white eggs are usually laid and the incubation period is 30 days. Nēnē goslings are flightless for about 10 to 14 weeks after hatching. Family groups begin flocking soon after the young are able to fly and remain in the breeding grounds for about a month. They wander about searching for food after that and may travel long distances from their breeding area.

Past & Present:
Fossil records show that nēnē used to live on all the main Hawaiian islands. It is believed that they were abundant (about 25,000 birds) on the Big Island before the arrival of Captain James Cook in 1778. Scientists believe that the Maui population became extinct before 1890. The decline in numbers was accelerated during the period of 1850 to 1900 due to aggressive hunting of the birds and collecting of their eggs. In 1951, the nēnē population was estimated at only 30 birds.

Their continued decline was attributed to the introduction of alien animals and degradation, and loss of habitat. Nēnē is extremely vulnerable to predation by introduced animals like rats, dogs, cats, mongooses, and pigs. In more recent studies, research shows that low productivity, perhaps caused by the poor available nutrition in their habitat and droughts also impact nēnē populations. Approximately 2,000 nēnē exist in the wild today with 460 on Maui, 146 on Moloka‘i, 800-860 on Kaua‘i, and 611 on the island of Hawai‘i.

Conservation Efforts:
Many public and private organizations have been actively operating and supporting propagation programs to reestablish nēnē in the wild. The State of Hawai‘i reintroduced them to Kīlauea Point and Hakalau Forest National Wildlife Refuges. The Wildfowl and Wetlands Trust in England has also played a major role in the survival of nēnē; they propagate and distribute nēnē to many zoos and aviaries.

Today nēnē are being raised in captivity at the Maui Bird Conservation Center at Olinda and the Keauhou Bird Conservation Center on the Big Island, both operated by the Zoological Society of San Diego. Young birds are then released into protected habitats by the State or National Park Service.

Nēnē was listed as an endangered species in 1967 under the Federal Endangered Species Act. The nēnē recovery plan was published in 1983. It outlines the essential elements to accomplish a goal of re-establishing nēnē to self-sustaining levels statewide. These elements are to minimize the mortality rate in the wild, continue release of captive-bred birds, continue predator control, and to protect and improve habitat where nēnē can maintain their populations naturally.