To understand why the Hawaiian goose (a.k.a. Nene goose) is so endangered, first you need to understand the incredible uniqueness of its native habitat.
Located out in the middle of the Pacific Ocean, the Hawaiian archipelago was created by active volcanoes, many of which still erupt and ooze lava today.
Hawaii (spelled Hawai’i by the indigenous natives) is the only state in the U.S. that’s still continually adding landmass. It’s also the only state not located on the North American continent, the only state surrounded by water, and the union’s youngest member. Hawaii is composed of eight main islands, which are denoted by the eight horizontal stripes on its state flag.
Most notably for the purposes of this story, Hawaii is crazy remote. It’s over 2,250 miles to the nearest landmass (False Pass, Alaska). As a result, most of the flora and fauna in Hawaii is endemic, meaning it’s only found in that area. Unfortunately, this makes virtually all Hawaiian animals more susceptible to extinction.
Hawaii has already lost more species (and currently has more endangered species) than any other state in the USA. Though Hawaii accounts for less than 0.25% of the country’s total land mass, over 25% of all endangered species in the US are native to the state. That’s why the islands are sometimes referred to as “the endangered species capital of the world.”
There are only two types of mammals native to the islands, the hoary bat and monk seal, both of which are endangered. Two types of endemic softshell turtles, the Chinese and Wattle-necked turtle, are also endangered. Several fish species (some of which are exclusive to the waters around the islands) are endangered. Almost all of the islands’ 40+ species of native birds are nearing extinction.
One of the most famous of these is the unique and interesting Hawaiian goose, which is sometimes known locally as the Nene. That’s the one we’ll be focusing on now, because this beautiful water bird has a very important story to tell.
- General Hawaiian Goose Facts
- Facts about Nene Goose Bodies
- Facts about Nene Behaviors
- Hawaiian Goose Breeding & Mating
- Why Are Hawaiian Geese Endangered?
- Conservation Efforts with Hawaiian Geese
- Why Saving Hawaiian Geese Is Important
General Hawaiian Goose Facts
1) The official scientific name of the Hawaiian goose is Branta sandvicensus. “Branta” is Latin for goose and “sandvicensus” for the Sandwich Islands (which is what Capt. James Cook called the islands of Hawai’i).
2) Locally, the bird is commonly referred to as the nene or nēnē, pronounced nay-nay. This name is derived from the call the Hawaiian goose makes. Besides the nay-nay call the bird typically makes in flight or as a warning when approached, it also moos like a cow and honks like Canada geese.
3) The Hawaiian goose is endemic and exclusive to the Hawaiian Islands. They were once found in the wild on Oahu, Maui, Kauai, Molokai, and Hawaii. However, only three Hawaiian Islands now have populations: Hawaii, Kauai, and Maui. On Hawaii, wild nene can be seen in Hawai’i Volcanoes National Park, Mauna Loa, and Pu’u Wa’awa’a. Haleakala National Park is the only location on Maui, and the Kilauea National Wildlife Refuge and outside Lihue Airport are the only two spots on Kauai.
4) The Hawaiian goose is the official state bird of Hawaii. It was named so in 1957. Amongst Hawaii’s other state animals, the state fish is the humuhumunukunukuapua’a, and the state insect is the pulelehua, a type of butterfly.
5) Though it is closely related to the Canada goose, the Hawaiian goose is the only species of goose that is not found in continental areas. Some scientists believe that the nene may have evolved from Canada geese that took a wrong turn during migration about half a million years ago. They must have liked the weather and scenery in Hawai’i, because they still haven’t flown back home.
6) Sadly, the Hawaiian goose is the only endemic goose species left in Hawaii. All eight other species have gone extinct. In fact, at least 32 different species of birds have gone extinct in Hawaii since 1778, and more than that are currently on the endangered list.
7) There was once a species of Giant Hawaiian goose, or nēnē-nui (Branta hylobadistes), that didn’t survive. The big bird was nearly four feet tall and weighed just under 20 pounds. That’s three to four times as big as today’s Hawaiian goose!
8) Today, the nene is the world’s rarest goose. Its total population was estimated at around 25,000 birds before Captain James Cook “discovered” Hawaii in the 1770s. But by the mid-1900s only about 30 were left, all of which were on the “Big Island” of Hawaii. The Hawaiian goose was finally declared endangered in 1967, and they remain protected today.
Facts about Nene Goose Bodies
9) Nene geese are significantly smaller than Canadian geese. They stand about 16 inches tall and roughly two feet long. They can weigh anywhere from 3.5 to 6.5 pounds, with the males tending to be a little larger than females. In contrast, Canada geese can get up to four feet long and 14 pounds.
10) The coloring of the nene is very distinctive. They have black faces, caps, and hindnecks. The cheeks are buff, and the bill, legs, and feet are black. Their feathers are a pattern of grey, brown and white, and they have a tuft of soft feathers under their chins. Their necks are deeply furrowed and have black and white diagonal stripes, which is caused by lines of white feathers atop black skin.
11) As is true with all geese, the Hawaiian goose is monomorphic. This means that both the males and females look basically the same (as opposed to other bird species, where males have more brilliantly colored plumage to attract their mates). Their goslings look slightly different than adults– typically a dull brown with less distinctness between colors.
12) One really interesting evolutionary tidbit about the Hawaiian goose is that their feet are not completely webbed, unlike all other geese. The evolution of longer toes helps them move around on the rugged, rocky terrain of Hawaii’s lava fields, which they tend to frequent more than ponds or lakes. Their feet also have extra padding to help with this.
13) Hawaiian geese can live a very long time for birds. In captivity, they have a potential lifespan of up to 24 years. The hard-knock life in the wild reduces their maximum life expectancy by a few years, to around 20. That being said, most wild nenes only live an average of eight years, which is less than half of their potential lifespan.
Facts about Nene Behaviors
14) Though Hawaiian geese are capable of flight, for the most part they spend their time on the ground. They have flown from one side of the Big Island to the other, crossing over 4,000 square miles. Nevertheless, this isn’t typical. Some nenes fly between nesting areas in the lowlands and feeding areas in montane regions, but they generally aren’t big travelers.
15) The Hawaiian goose is an herbivore, with a diet based on grazing on grasslands and browsing in shrubs. They have at least partially adapted to the presence of humans, and are particularly keen to graze on golf courses. They’re also known to follow farmed cattle in order to feed on the young grass shoots that are left behind. They eat leaves, grass, shrubs, fruit, and flowers.
16) Amazingly, these geese don’t require much in the way of fresh water because they have adapted so that grasses and berries supply most of their hydration needs. That being said, if they’re given water, such as they are in captivity, they will happily drink it.
17) Hawaiian nēnēs can be found anywhere from sea level to 8,000 feet in elevation. They like to inhabit grasslands and shrublands, as well as coastal areas and lava plains with vegetation. They’re also fond of golf courses and pastures, where fresh grass shoots are abundant. They like to nest on the slopes of volcanoes, often beneath shrubs surrounded by barren lava. These areas are called kipuka.
18) In 2012 on the island of Kauai, wild Hawaiian geese caused serious problems at the Lihue Airport because they liked to hang out at the golf course next door. The Department of Transportation was spending several hundred thousands of dollars each year to chase them out of flight paths. Officials eventually budgeted nearly five million dollars to move them elsewhere.
19) Though they are considered waterfowl, Hawaiian geese rarely swim. Unlike other geese, they don’t even need open water to survive. They do, however, seem to like taking a dip in a cool spring whenever the opportunity presents itself.
20) Hawaiian geese are truly odd birds: Unlike most geese, they aren’t migratory. They typically only move within the island boundaries of where they live. So nenes from the island of Hawaii do not fly to Maui or Kauai, and vice versa. This unusual quirk has yet to be explained by science.
READ MORE: 60 Weird Animals Around the World
Hawaiian Goose Breeding & Mating
21) Generally, young Hawaiian geese reach reproductive age at around three years old, though they have sometimes matured as early as two years. At this time, males will court females, but females will make the ultimate decision as to who will be her mate.
22) Nēnēshave the longest breeding season of all wild geese. They mate any time between August and June (or essentially all year). But November, December, and January are the prime mating season.
23) A mated Hawaiian goose and gander will remain monogamous, staying together until one mate dies. Surviving spouses will often find a new mate when widowed. On rare occasions, mated couples will separate if their breeding seasons haven’t produced offspring. This is also true for most species of geese and swans. But ducks are more into seasonal swinging, going steady for only one mating season at a time.
24) Unlike other water birds, Hawaiian geese usually mate on land. Other small geese can do the same, but, by and large, geese generally prefer to mate on the water.
25) Female nenes choose their nesting sites and prepare them alone. The nests are often constructed in hollows on the ground, where they’re hidden by vegetation. A kipuka– a rogue bit of shrubbery within a desolate lava field– is a favorite nesting spot for Hawaiian geese. These nests are lined with down and reused each season.
26) A Hawaiian goose typically lays between one and five eggs. The average is usually about three, though the geese on Kauai are prone to having four eggs in a clutch. The female incubates them alone, which takes roughly a month.
27) Though hatchlings can leave the nest within hours of hatching, they cannot fly until about three months later. This makes them vulnerable to predators, so the young normally stay with their parents until the next breeding season. Typically, the family will remain at the safer breeding grounds for a few months before moving off to better feeding areas.
Why Are Hawaiian Geese Endangered?
28) The populations of Hawaiian geese (and countless other endangered animals) began to severely decline with the rise of European colonialism. They were hunted relentlessly for food and feathers. And their habitat was destroyed by the development of intrusive agricultural systems.
29) The introduction of the small Indian mongoose in 1883 further decimated the Hawaiian goose population. This was an attempt to control the rats that thrived on the islands’ sugar cane plantations. Unfortunately, rats are nocturnal and mongooses are diurnal (i.e. operate during the day), so the two species rarely crossed paths. Instead the mongooses hunted all incarnations of the daytime-loving geese, including adults, chicks, and unhatched eggs.
30) Adding to the problem, other introduced species– including dogs, cats, feral pigs, and rats– also became predators of the nene in one form or another. Meanwhile, domesticated livestock were given favor for grazing habitat, which limited the access geese had to their preferred food sources.
31) Predatory animals made short work of the geese because they had never needed to defend their nests before, due to there being no natural predators on the islands. Female geese will actually go into a hypnotic state when nesting, largely unaware of their surroundings, which makes them vulnerable.
32) Mosquitoes created issues for the Hawaiian goose as well. Mosquitoes spread avian malaria among many of the native birds in Hawaii. Avian malaria works much the same way as the human kind, which is caused by single-celled protozoans transmitted via the bite of an infected mosquito. However, there are many more types of mosquitoes that transmit avian malaria.
33) Inbreeding among the diminished population of geese also caused some problems. So did the loss of adaptive skills that occurred in the captive breeding program, which was launched in an attempt to revive the population. Consequently, the majority of the wild population doesn’t breed successfully.
34) With the mongoose situation remedied (i.e. killed and banned), the largest threat to adult Hawaiian geese today may be cars. They’re frequently run over by speeding drivers, particularly during peak breeding and molting season, when the nene are incapable of flight.
35) Due to habitat loss and severe ecosystem disturbances, it is likely that the Hawaiian goose will always require some form of human management in order to survive.
READ MORE: Beautiful Birds of the Galapagos Islands
Hawaiian Goose Conservation
36) Despite their total population numbers being calculated as low as 24 in the mid-1900s, it wasn’t until 1967 that Hawaii’s goose species was listed as endangered under the Federal Endangered Species Act. Thankfully, efforts to save the nene had already begun several years prior to this listing.
37) Starting in the 1950s, conservation programs in Hawaii and at the Wildfowl and Wetlands Trust nature reserve (in Slimbridge, England) had great success breeding Hawaiian geese in captivity. Collectively, they released over 2300 birds back into the wild. Unfortunately, due to the aforementioned predators, these initial repopulation efforts were a failure.
38) There are still Hawaiian geese in England today. The original captive breeding effort and reserve estuary on the east side of the River Severn were initiated by naturalist/artist Peter Scott. He founded the Wildfowl and Wetlands Trust, whose nine reserves protect over 7400 acres. In 2005, the WWT reintroduced the Laysan teal (one of the most endangered ducks on earth) to Hawaii.
39) Despite their difficulty with breeding in the wild, the nene goose population has been on a steady rise for over two decades. It currently sits at 2,500 to 3,000 birds, with regular additions introduced from captivity. Recent repopulation efforts have had more success because their predators have been dramatically reduced.
40) In April of 2018, the U.S. Fish and Wildlife Service suggested moving the Hawaiian goose from Endangered status to Threatened. After 51 years on the endangered species list, the population had stabilized to such an extent that the nene is “no longer in immediate danger of extinction.”
Thankfully, this improved conservation status will still come with significant efforts to protect these birds from habitat loss, invasive predators, and traffic accidents.
Why Saving Hawaiian Geese Is Important
The recovery of the Hawaiian goose, while not yet complete, is a testament to the fact that we CAN do something to help the endangered species that remain.
It all started with just a few concerned people– nēnē goose appreciators– who saw a troubling problem and worked for decades to right it. Along the way, they inspired others to help save Hawaiian geese, which spawned many more efforts to help other endangered animals in Hawai’i. That, my friends, is the power of positivity!
The Wildlife and Wetland Trust of Britain was instrumental in restoring the Hawaiian goose population, spearheading this project for over six decades.
Island Conservation was founded in 1994, and given international non-profit status in 1997. That organization was instrumental in clearing the invasive predators from the Hawaiian Islands so that the nene could return home safely. The Honolulu Zoo Society continues to breed Hawaiian geese in captivity, as well as educating the public about them and more of Hawaii’s native wildlife.
At a time when negativity seems to dominate the news cycle, the Hawaiian goose recovery proves that when we do something benevolent, it can have a positive effect. If enough people care about conservation– whether of an endangered species, an entire ecosystem, a historic site, or a traditional culture– it often produces encouraging results.
Dwindled animal populations can increase (read about Mekong river dolphins in Cambodia). Rainforests are protected (see: Serranía del Chiribiquete National Park in Colombia). Indigenous people get a chance to profit from tourism on their native land (such as in Kenya’s Maasai Mara conservancies). If we as a society keep working towards these positive goals, we can reach them.
For those of us interested in preserving the planet, these victories are both much-needed and hugely inspirational. Every animal, forest, river, coral reef system, and indigenous culture plays a vital role within the ecosystem in which they are found. But regardless of their location, they each have things to teach us all, and they deserve our respect and protection.
Thanks to these 40 facts about the Hawaiian goose, we now know how special these birds are. We know that they’re unique among geese, but– like all geese– they lead lives devoted to their mates and their offspring.
Nenes manage to survive in some horribly inhospitable places (see: barren lava fields), yet they were sent to the brink of extinction due to human carelessness and greed. We can do better than that.
So, with that in mind, now is a great time for all of us to start getting behind these great conservation causes. If we prioritize them, we may just find ourselves with a much more inspired and inspiring world. People today can become a positive part of the planet’s future. Together, we can save the species. –Jonathon Engels, Featured Image by Jason Crotty courtesy Flickr via CC 2.0