Hawaiian Goose or Nene
(Branta sandvicensis)
The Hawaiian goose, or nene to give it its local name, is Hawaii’s state bird. It got its name from the ne ne sound of its soft call. Scientists believe that it was once almost identical to the Canada goose, but after years of evolution the two species have diverged. The nene, with its long neck and black-and-cream markings, rarely swims. Its feet are only half webbed but have long toes suitable for climbing on the rocky lava flows of Hawaii. And since the nene evolved on a tropical island, with no need to escape either cold temperatures or predators, flying was less important for it than for the Canada goose—thus its wings are much weaker.
Prior to the “discovery” of the Hawaiian Islands by Captain James Cook, there were probably some twenty-five thousand or more nene. But during the 1940s, the species was almost completely wiped out by hunters, because there were no laws to prevent shooting the birds during the winter breeding season. In addition the usual invasive species, in the form of pigs, cats, mongooses, rats, and dogs, wreaked havoc as they preyed on eggs and young birds. The cats even killed adult geese. It is the same story for many large birds of the islands—without the ability to fly fast or far, they were easy prey for invaders.
By 1949, only thirty individuals remained in the wild. There were, however, other nene in captivity—some at the state endangered species facility at Pohakuloa, Hawaii, and some that had been sent to Slimbridge in the UK. Captive breeding began in these two sites for eventual return to the wild.
Recently I had a long talk with Kathleen Misajon, who has been working with the nene since 1995. After finishing her degree, she applied for a three-month internship in Hawaii to continue working with the nene—and she is still there! Breeding the nene is not difficult, she told me, and since 1960 more than twenty-seven hundred have been raised and released. The problem—as for the giant panda, and many other species—has been trying to create a sufficient suitable and safe environment for their survival when returned to the wild.
Park employee Kathleen Misajon with long-term (over twenty years) volunteer Lloyd Yoshina banding a wild nene at Hawaii Volcanoes National Park, 2006.(Ron McDow)
Much of Hawaii’s low-lying coastal areas have been developed, and that which remains is under continuous threat from further disturbances by humans and by invasive non-indigenous plants. But, says Kathleen, “Perhaps a bigger problem is that so much habitat was destroyed so long ago that no one really knows the exact components of ideal nene habitat.” Maybe before all the human-caused disturbance to that unknown ideal habitat, the geese were better able to withstand periods of drought or heavy rainfall that are detrimental to them today, particularly during the breeding season.
The nene face many other threats, too. In addition to the ongoing problem of the introduced predators, increasing numbers of nene are being hit by cars. Unfortunately a major state highway cuts right through the park, and it separates an important nene breeding and roosting area from their feeding grounds. Normally the adults fly across, but when they have goslings they must walk, exposing themselves and their young to danger. It is the same when they are attracted to the grassy shoulders of roads after they have been mown. And those that venture onto the golf courses may even be killed by golf balls.
Kathleen told me she thinks the nene may never be 100 percent self-sustaining—the threats are too great. “However,” she said, “the overall population is on the rise, and with proper management we can help sustain the wild populations.”
Protection from Predators: “We Can’t Just Abandon Them to Their Fate”
In the 1970s, a reintroduction program began in the Hawaii Volcanoes National Park. The areas selected for release were low-lying sites thought to be historical nene habitat. It was a very simple program: Several breeding pairs were kept in captivity, and when their young had fledged they were simply allowed to go free. Then, in the 1980s, additional young birds were released from the state breeding program into the park. During this twenty-year period, however, things did not go well for the youngsters when they were let out into the big wide world. This was not surprising, for the park attempted predator control only in the area immediately surrounding the release pens.
Thus the birds released into the wild saw high mortality and low breeding success. Clearly it did not make sense to go on breeding more and more young birds and abandoning them to their fate. A new strategy was developed that called for intensified predator control over a much larger area around selected breeding grounds. The next step was to erect fencing around one large nesting area and a suitable pasture to keep out the feral pigs that were suspected of killing many young birds as well as taking eggs, since the goslings were disappearing even when supplementary food was offered. Once four hundred acres was completely surrounded by a pig-proof fence, things improved, and during subsequent breeding seasons most goslings fledged.
Since the early 1990s, the population has grown to about two thousand individuals living in the wild, with the number rising each breeding season. They are living on four islands—Kauai, Maui, Molokai, and Hawaii. The nene is doing best on Kauai where there is no established mongoose population and grassy, lowland habitat is more available. Although small-scale captive releases still occur on Maui and Molokai, the current strategy focuses on minimizing the threats to the wild populations.
Now, Kathleen told me, they are experimenting with ways to keep out cats and mongooses using new fencing techniques. The design comes from Australia where so much work has been done on controlling predators of all kinds. The two-yard-high fence is constructed so that when a cat or mongoose climbs up from the outside, the wire curves outward and downward, leaving the marauder virtually upside down clinging to floppy wire netting.
Kathleen gave me an example of the danger posed by cats. It took place the day after Christmas 2001. She noticed a goose flying over an open lava field toward some vegetation where she felt she might be able to find its nest. As they are often remote and therefore not easy to find, she was excited as she trekked across the bare lava. Presently she came upon the gander, guarding his nest site. She moved on—and there she found the partially eaten female beside her eggs, now cold. The cat was still there, lying beside the carcass, glutted on goose meat. That was not the only proof she had of the hunting success of cats.
Nevertheless, the scientists and volunteers do not plan to give up. A few days after talking with Kathleen, I spoke with Darcy Hu, who has been working with nene in and around Hawaii Volcanoes National Park for more than fifteen years. I wanted a story with a happy ending—and she came up with one. It began on the day when she and her volunteer crew got a thirdhand report of a dog attack at Devastation, an area on the summit of Kilauea. They knew there were several nene there, including at least one banded pair with three partly grown goslings. The report merely indicated that the attack had involved at least one adult and one youngster.
Quickly they drove to the scene, but at first found no sign of bird or dog. Then they spotted and caught two goslings, too young to fly. At the same time, the call of an adult sounded deep in the forest. Not liking to abandon the two goslings—even if the calls were from a parent, there was no assurance the family would meet up, and the youngsters surely could not have survived on their own—they waited awhile. Soon the calls stopped. Although they searched for a while, they found no nene, and heard no more calls.
Still hoping the parents might show up, Darcy rigged a wire-mesh pen close to where the goslings had been found and left them there for several days, spying from a distance in case the parents returned. But there was no sign of any adult, and because the goslings were getting thin, they were moved to a captive facility. There, fortunately, an older nene couple was persuaded to adopt them. “Nene don’t need help feeding themselves,” wrote Darcy, “but they do have an almost physical need to be with other nene—you rarely see even unpaired individuals alone, and pairs and families almost always travel as a unit.”
A few months after capturing the two young goslings, Darcy and her team spotted a pair of adult nene and a gosling about a mile from Devastation. Quickly they caught and banded the gosling and, as the parents stayed nearby, they were able to read their bands. “It was the missing parents and the third sibling of our two orphans!” wrote Darcy delightedly. The wild youngster was smaller and not as developed—food had surely been more plentiful and nutritious in captivity. But all the family had survived the dog attack. “We counted ourselves very lucky,” Darcy wrote, “to have been able to conclude this particular story with a happy ending.”