A Hawaiian Goose (Branta sandvicensis; "Nēnē" in Hawaiian) roosting atop one of the steep basalt cliffs in the Kilauea Point National Wildlife Refuge, north Kaua'i. Hawai‘i’s state bird. The nēnē measures between 22 to 26 inches in length, has a black head and bill, yellow-buff cheeks, a buff neck with dark furrows, and partially webbed black feet. Its loud calls are like those of the Canada goose and when disturbed, its call resembles the “moo” of a cow. ossil records show that the 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. A small population was reintroduced at Kīlauea Point National Wildlife Refuge in 1991. Approximately 1,700 nēnē exist in the wild today. The species is federally protected under the Endangered Species Act.The nēnē is extremely vulnerable to predation by introduced animals like rats, dogs, cats, mongooses, and pigs. In more recent studies, research shows that continuing decline of the nēnē population in the wild can be attributed to low productivity, perhaps caused by the poor available nutrition in their habitat.