28-11-2016 JURONG, SINGAPORE - HAWAIIAN GOOSE (Branta sandvicensis)

The Hawaiian goose or the nene (Branta sandvicensis ) is the world's rarest goose. It is thought that the nene evolved from the Canada goose, which most likely arrived on the Hawaiian islands about 500,000 years ago, shortly after the island of Hawaiʻi was formed.

Adult male Hawaiian geese have a black head and hindneck, buff cheeks, and heavily furrowed neck. The neck has black and white diagonal stripes. Aside from being smaller, the female is similar to the male in coloration. The adult's bill, legs, and feet are black. It has soft feathers under its chin. Goslings resemble adults but are a duller brown and with less demarcation between the colors of the head and neck, and striping and barring effects are much reduced.

Native to the Hawaiian Islands, the Hawaiian goose today is found most commonly in Hawaii, in and around the Hawaii Volcanoes National Park, and on Maui in Haleakala National Park. A large and increasing population also lives on Kauai Island, and the animal has recently been reintroduced on Molokai Island. They don't migrate and inhabit various habitats, including scrub forests, grasslands, volcanic slopes with sparse vegetation, coastal dunes, and lava plains, and related anthropogenic habitats such as pasture and golf courses. Some populations migrated between lowland breeding grounds and montane foraging areas.

Hawaiian geese are diurnal birds. They sleep on the ground with their feet tucked under their bodies. They live in family groups that consist of a mating pair and their young. Hawaiian geese may live in flocks of as many as 30 birds, some groups being more loosely formed than others. Dominance ranking depends on the family unit’s size. Males defend against other geese the territory that immediately surrounds their nests and families. Hawaiian geese spend most of their time on the ground but they are capable of flight, with some individuals flying daily between nesting and feeding areas. They do swim, mostly in ponds and lakes. They spread the oil, using their beak, from their oil gland onto their feathers to waterproof them.

Hawaiian geese are monogamous, forming life-long pair bonds. From August through April is the breeding season, peaking from October to March. These birds nest in solitary pairs and the nest is built by the female, being a shallow scrape in the ground, lined with vegetation and down, usually sheltered by tussock grass or rock. The same site is often reused year after year by the same pair. 2-5 creamy white eggs are laid, and the female incubates them for about one month. The goslings are precocial and can feed themselves, but usually remain with their parents for one year. They fledge at around 10-12 weeks old, and around 2-3 years old they become reproductively mature.