The Nene (Branta sandvicensis), also known as the Hawaiian Goose, is a species endemic to the Hawaiian Islands. This bird holds the title of the official State Bird of Hawaii, a recognition granted in 1957. The Nene is considered the world’s rarest goose species, a status resulting from a dramatic population collapse that nearly led to its extinction in the mid-20th century.
Physical Description and Habitat
The Nene is a medium-sized goose, typically measuring about 25 inches in length, with males being slightly larger than females. Its plumage is distinctive, featuring a black face and crown that contrasts sharply with cream-colored cheeks. The buff-colored neck is marked with oblique dark streaks, giving the feathers a furrowed appearance.
The Nene possesses several physical adaptations that reflect its highly terrestrial lifestyle, unlike most other waterfowl. It has longer legs and less webbing between its toes, which evolved to help it walk and run over the rough, uneven terrain of volcanic lava flows. This terrestrial adaptation is also suggested by its somewhat smaller wings compared to its closest relatives.
Current populations are established on Hawaiʻi Island, Maui, Kauaʻi, Molokaʻi, and Oʻahu. It inhabits a wide range of terrestrial environments, from sparsely vegetated high-elevation lava fields and volcanic deserts to coastal dunes, native shrublands, and human-altered areas like pastures and golf courses.
Ecology and Lifestyle
The Nene is primarily a herbivore, grazing on the leaves, seeds, flowers, and fruits of over 50 native and non-native plant species. A notable food source is the native ʻōhelo berry, which is particularly favored on Hawaiʻi Island. As a non-migratory species, the Nene does not undertake the long seasonal flights typical of mainland geese. Instead, it makes localized movements between feeding and nesting areas on a single island.
This species is monogamous, forming pair bonds that last for life, and it engages in relatively simple courtship displays. The Nene is unique among geese because its main breeding season occurs during the winter months, typically from August through April, with nesting concentrated between October and March. This timing aligns with the wet season, when vegetation growth provides ample food and cover.
The female builds her nest as a shallow scrape on the ground, often hidden within dense vegetation, and lines it with plant material and down feathers. A clutch usually consists of two to five eggs, which the female incubates for approximately 30 days. The goslings are able to follow their parents and feed themselves shortly after hatching, but they remain dependent on parental care for several months, often staying with their parents for up to a year.
History of Decline and Restoration Efforts
The Nene population experienced a dramatic decline following the arrival of European settlers, driven by habitat loss and the introduction of non-native predatory mammals. By the early 1950s, the species teetered on the brink of extinction, with only about 30 birds remaining in the wild. Introduced predators like the small Indian mongoose, feral cats, dogs, and pigs preyed heavily on the vulnerable, ground-nesting adults, eggs, and goslings.
The species was officially designated as Endangered under the U.S. Endangered Species Act (ESA) in 1967, which mobilized significant conservation resources. A large-scale captive breeding and reintroduction program began in 1949, successfully releasing over 2,800 captive-bred birds into the wild through 2011. This sustained effort, combined with ongoing management, allowed the population to slowly recover.
Due to the success of these decades-long conservation strategies, the U.S. Fish and Wildlife Service (USFWS) officially downlisted the Nene’s status from “endangered” to “threatened” in 2018. Current wild population estimates now hover around 3,000 to 3,200 birds, marking a significant milestone in endangered species recovery. Continued conservation work remains necessary, including intensive predator control programs, habitat protection through fencing, and management of human interactions.