The Nene Goose: Hawaiian State Bird on Endangered Species List
Kingdom: Animalia
Phylum: Chorodata
Class: Aves
Order: Anseriformes
Family: Anatidae
Genus: Branta
Species: Branta sandvicensis (“sand” a reminder that the Hawaiian Islands were once known as the Sandwich Islands.)
Of course, most of us don’t speak scientifically and don’t give much thought or consideration to the scientific classifications of the wildlife around us. So it would be more appropriate to introduce you to the Nene (pronounced nay-nay) Goose, also known as the Hawaiian Goose.
This state bird of Hawaii is endemic (exclusively native) to the Hawaiian Islands and can be found in the wild on the slopes of the volcanoes on the islands of Hawaii (Hawaii Volcanoes National Park, Mauno Loa, Puu Wa’awa’a) and Maui (Haleakala National Park), and also in the lowlands of Kauai. They can also be seen in the Honolulu Zoo on the island of Oahu.
There may have been as many as 25,000 Nene geese at the time of Captain Cook’s arrival to Hawaii, but by the mid 1940’s the population had been reduced to only 50 birds. They became the state bird on May 7, 1957, with an estimated number of 30 or less, but their vanishing population was not recognized as an endangered species until 1967.
Foraging animals like goats and cattle, as well as introduced predators such as cats, dogs, and mongooses played a part in the decline of their numbers by often feeding on the Nene eggs and goslings. Introduced plants and cover plants, competed for space with the native greenery that was a part of the herbivorous (plant-eating) diet of the Nene. Humans also share the blame for encroaching on their habitat and hunting the Nene during breeding season was legal up until 1907.
At least nine different species of geese are believed to have evolved in the Hawaiian Islands, eight of them flightless. The Nene belongs to a family that includes swans, whistling ducks, and true geese. Its closest relative is the Canada Goose (Branta Canadensis), although the Nene is a little smaller, and it is believed that they share a common ancestor.
A variety of soft and apparently conversational calls have been heard and described, and the Nene receives its name from one of them. However, the loudest and most commonly recognized call sounds like a “honk” or “ha-wah,” and is considered to be very similar to the call of its Canadian cousin.
The Nene females and males are similar in size (the male is slightly larger) with identical plumage (monomorphic); they grow to heights of 21-26 inches (medium-sized in comparison to other geese) and weigh an average of 4.5 pounds. Diagonal rows of cream-colored feathers create a furrowed pattern down their neck, complimenting the black feathers found on the back of their necks, their faces, the tops of their heads, and their bills. Cream-tipped feathers cover their dark brown to dark gray bodies.
The Nene lives far from standing water on rugged lava flows, unlike other geese. Their smoky- black feet allow them to walk easily on the rugged lava of their habitat because they have less webbing between their toes than their cousins who spend much of their time in standing water. The Nene at the Hawaii Volcanoes National Park live in an area that sees maybe 90 inches of rainfall a year. They forage the dry land for shrubbery and grass; their water needs are met from the abundance of berries in their diet.
The Hawaii Volcanoes National Park began a captive breeding program in the 1970’s. Population growth is slow because of natural predators, and the human being. Nene are hit by cars on the road, and often by golf balls when they are attracted to the grassy courses in the area.
During the summer, Nene gather in traditional flocking areas to socialize with other geese and the unpaired begin choosing mates. By the end of the summer, the distinct pairs have separated from the other pairs, a distance strictly maintained throughout the breeding season.
The Nene tend to be monogamous and mate for life, although there have been a few “divorces” noted, as well as some trios consisting of a male and two females. Nene females usually mate at two or three years of age, despite being biologically ready to reproduce in the first year. The Nene Goose is the only goose in the Northern Hemisphere to breed during the wet season, generally beginning in October and ending sometime between February and April.
The nests are constructed on the ground, usually sheltered by shrubs and small trees, and can hold between 5-8 eggs. An egg is laid every day or so, the incubation period is 30 days. The male stands guard, perched on a nearby boulder or other elevated area. The female does all the incubating, leaving the nest only to feed.
The newly-hatched goslings receive a one-day or so rest period in the nest with the female. Then the whole family leaves the nest behind and walks to a brooding location (place to rear the young), sometimes as far as several miles away. They stay in the brooding area for 8-12 weeks (depending on the food supply), until the goslings either fledge (fly) or die. Around the time that the goslings are fully-feathered, the adults moult (shed old feathers and grow new ones), keeping a low-profile during this dangerous flightless phase.
The rare birds are so highly valued in the Hawaiian Islands that untimely deaths due to human error, such as feeding them while visiting one of the Volcano Parks, or running one over with a vehicle, are reported in the newspapers.
If allowed to do so, Nene can live to be over 30 years old, but they have many odds to overcome. The conservation effort has so far been successful in keeping them from becoming extinct, but the fight is far from over and the numbers are nowhere near the hopes that the people of Hawaii and bird-lovers everywhere hope to someday see.
