Nēnē or the Hawaiian Goose, Branta sandvicensis, is the rarest goose in the world. It is endemic to Hawaiʻi but due to captive breeding efforts can be found in a few other places, most notably WWT Slimbridge in Gloucestershire, England. A few escapees are also occasionally seen throughout Europe. By the mid-1940s, the Hawaiian goose population was alarmingly low, with an estimated population of less than 50 individuals. However, the bird’s beauty and rarity led to its recognition as the official emblem of the Territory of Hawaiʻi in 1957 and later as the state bird in 1988.
Hawai‘i was once home to at least five species of geese, but today only the nēnē, or Hawaiian goose, remains. These geese are mostly dark brown or sepia with a black face and crown, cream-colored cheeks, and a buff neck with black streaks. Females are smaller than males, and nēnē are known for their longer legs and less webbing between their toes, which makes it easier for them to walk on lava flows. Nēnē feed on the leaves, seeds, flowers, and fruits of at least 50 different native and non-native grasses, sedges, composites, and shrubs, with their diet varying depending on location and habitat. Currently, non-native grasses are important in mid- and high-elevation habitats. In addition to feeding, nēnē facilitate seed dispersal and play an important role in influencing the species composition of early successional plant communities.
Historically, flocks of nēnē moved between high-elevation feeding habitats and lowland nesting areas, where they engaged in simple courtship displays. Breeding pairs usually return to the previous year’s nest site, which is typically in dense vegetation, such as a kīpuka if available. Nests consist of a shallow scrape lined with plant material and down. Females lay two to five eggs, which hatch after 30 days. Young nēnē are hatched or born in an advanced state and are able to feed and move independently, but they remain with their parents for up to a year.
Despite their remarkable adaptability, the nēnē were hunted to near extinction by humans and fell victim to introduced predators such as rats and dogs. By 1967, the nēnē population had dwindled to fewer than 30 birds in the wild, and they were listed as endangered under the Endangered Species Act. However, through conservation efforts and the protection provided by the Act, the nēnē population has now recovered to over 3,800 statewide, with over 60% of the population located on Kaua‘i.
The successful efforts to recover the nēnē demonstrate the effectiveness of the Endangered Species Act. However, recent rollbacks to key regulations under the Act could put hundreds of other animals and plants at risk of extinction. It is important to continue to protect imperiled species like the nēnē to ensure their survival for future generations.