On the U.S. Pacific island state of Hawaii, an invasive predator is threatening many native bird species with extinction. The predator is the mongoose, a non-native mammal introduced to the island chain over a century ago to control rats in the sugar cane fields. Now, environmental groups say, it's the mongoose that's out of control, feeding on the eggs and chicks of the island's many ground-nesting birds, including several endangered species that lay just one egg per year.
Many people think of the Hawaiian islands as a Pacific paradise, a string of tropical islands lush with exotic flora and fauna.
But the islands' native species - especially birds - have been under increasing pressure since humans first settled there.
"Hawaii is the bird extinction capital of the world. The 50th state has a reputation as an island paradise, but I think that a lot of people don’t realize that through a long history of animal and plant introductions, Hawaii’s bird population has been decimated," said George Wallace, a vice president at the American Bird Conservancy.
The ABC was among the first groups to sound the alarm about mongoose on the island of Kaua. The predator can be devastating to water birds that come ashore to raise just one chick per year.
"Mongoose are not great climbers of trees but they are very capable of taking the nestlings and eggs of ground-nesting birds, and that would be particularly devastating for Hawaiian water birds," Wallace said.
The mongoose have no natural enemies on the Hawaiian islands. They are a common sight along roadsides and near garbage dumps. The island of Kauai had been free of mongoose until recently so its birds are doing better than those on the other islands.
"There are over 100 species of birds that are unique to Hawaii and only exist there. Over 71 species have gone extinct and there is another 31 that are listed as threatened and endangered,” said Brad Bortner, with the U.S. Fish and Wildlife Service.
Mongoose are just one of many threats facing Hawaii's birds. There are other invasive animals and plants, insect-borne diseases, and habitat destruction. Bortner says the Fish and Wildlife Service has joined with other groups to restore habitats, install predator traps and fencing and support captive breeding programs for such endangered bird species as the Hawaiian crow.
Recent surveys show that the populations of some native Hawaiian bird species - unique to the islands - are down to just a few hundred individuals.
George Wallace says the lack of resources limits the response to the crisis.
"If you look at all of the bird species listed under the Endangered Species Act, there are about 90 in the United States, one third of them occur in Hawaii, but only 4 percent of the funding for the recovery of endangered species actually goes to these birds on Hawaii,” Wallace said.
To raise public awareness about Hawaii's threatened birds, the American Bird Conservancy recently released a 30-minute documentary called Endangered Hawaii. The video is available on the Internet and is being distributed to schools and government agencies.