The Hawaii state bird is an endangered species, constantly threatened by mongoose, dogs, rats and other introduced animals even as they cope with the loss of grasslands and forests to development. 

But nene geese have found a safe home among the green golf course fairways and ponds of a Kauai resort, and they are thriving — exploding from just 18 birds in 1999 to some 400 today. 

In fact, the population at Kauai Lagoons has grown so fast and large the geese are now considered the threat. They pose a public safety hazard to the commercial airliners taking off and landing at the airport next door, forcing the state to scramble to devise a plan to move them somewhere else.

“With the numbers that are nesting, it’s just like, boy there are going to be more and more birds there,” said Paul Conry, administrator of the state Division of Forestry and Wildlife. “If we don’t take action now, they will even get higher and higher in the future.”

The dangers geese present to airplanes became well known after a flock of Canada geese crossed paths with a US Airways plane over New York City in 2009, knocking out both engines and forcing the pilot to bring the aircraft down in the Hudson River.

Similar incidents have caused deaths: 24 airmen in Alaska were killed when a flock of Canada geese got sucked into the left side engine of an Air Force plane in 1995. The jet crashed 43 seconds after takeoff. 

The black and beige feathered nene is unique to Hawaii, but is believed to have descended from Canada geese. It grows about 2 feet long, and is the state bird. 

Already, Hawaii’s state Department of Transportation spent $417,000 this fiscal year to have workers chase birds — mostly nene — away from the path of airplanes in Lihue 12 to 14 hours a day, seven days a week. That’s more than the $393,000 it spent to scare birds at the much-larger Honolulu Airport, which has more than twice as many flights as Lihue.

Exacerbating the problem is that some of golf course holes favored by the geese are not just next to the airport, but squeezed in between a “v” shaped angle formed by two runways. Between 2008 and 2010, officials reported seeing nene more than 5,000 times at the airport. Most of them were at the southern end of one runway, a critical area for airplanes landing and taking off. 

Citing the public safety threat, Gov. Neil Abercrombie in April signed a proclamation suspending some state laws to enable the administration to swiftly move all the nene out of Kauai Lagoons. 

Even so, it’s expected to take five years to finish the job in part because the birds don’t congregate at the resort unless it’s breeding season, which generally starts in October and goes through March. This makes it difficult for the animals to be rounded up. The state also needs to find new, safe homes for the birds. 

The state captured and moved 10 of them to Maui after the proclamation was signed on April 14, but that was all it was able to do so far this year, Conry said.

The state plans to take the geese to other islands that are already home to nene. Conry said it’s not clear yet how much the plan will cost. In addition to Maui, the Big Island and Molokai also have wild nene populations. Nene live on other parts of Kauai, but geese taken elsewhere on the island often return to the place where they hatched.

“That doesn’t tend to work as well. A lot of those birds tend to show up back at the Kauai Lagoons property relatively quick,” said Jeff Newman, deputy field supervisor U.S. Fish and Wildlife Service’s Pacific Islands office. 

The 800-acre site features a beachfront Marriott hotel, 38 acres of lagoons, and a 27-hole golf course. Officials for Marriott, which also plans to build Marriott condominiums and Ritz-Carlton villas on the property, declined to comment on the situation.  

The most important need for the birds in their new homes will be protection from predators, Newman said, noting the main reason nene thrive at Kauai Lagoons is because mongoose haven’t become established on Kauai. 

The small, elongated mammal native to Southeast Asia and India was introduced to Hawaii in the 1880s to control rats eating sugar cane, Hawaii’s economic mainstay at the time. The mongoose failed to keep the rats in check, but the animal has wreaked havoc on native bird populations lacking innate defenses against introduced predators. 

The nene was almost wiped out, with the total population numbering just 30 by 1952. The numbers have since rebounded to nearly 2,000 thanks to scientists who have bred them in captivity. The Kauai Lagoons population is descended from geese hatched in captivity and released to the wild.

It’s unusual to move an endangered species, but officials aim to use the Kauai Lagoons birds to re-establish populations on other islands in addition to protecting public safety. 

“It’s something we wouldn’t normally try and do, obviously, but we’re going to help support the state in their implementation of the governor’s proclamation,” Newman said. “They’re going to do it in a way that hopefully will not be harmful to the nene and that will hopefully try to achieve long-term recovery goals for nene.”