LIHU'E, Kaua'i — With the rabbits gone, state and federal wildlife officials are focusing on eradicating the rats on Lehua Island.

Officials say native plants, wildlife and seabirds will be restored by eliminating the rats roaming Lehua, an uninhabited 290-acre, crescent-shaped island less than a mile north of Ni'ihau.

"Rat eradication will clear the way for native species to come back to Lehua on their own or be reintroduced as part of the restoration plan," said Chris Swenson, Pacific Islands Coastal Program coordinator for the U.S. Fish and Wildlife Service.

Swenson said the Polynesian rats were first documented on Lehua in the 1930s.

"Rats eat many native species, including seabirds, eggs, chicks and sometimes adults; native plants, seeds, leaves and roots; and native invertebrates, insects as well as intertidal invertebrates like crab," Swenson wrote in an e-mail to The Garden Island newspaper.

Bait pellets containing the poison diphacinone, an anticoagulant, will be dropped over the island using a bait hopper carried under a helicopter. Diphacinone causes internal hemorrhaging in rodents, resulting in a painless death.

This method was used on the Mokapu islet off Moloka'i in February.

Details of the rat eradication were provided in a draft supplemental environmental assessment released by the U.S. Fish and Wildlife Service and the state Department of Land and Natural Resources.

The agencies will hold a public meeting July 24 on Kaua'i to gather public comment on the draft assessment, which supplements a final assessment approved in September 2005.

The draft says the eradication will take place from December through February, when the rat population and native nontarget migratory species present on Lehua Island are are at their lowest numbers.

If the application of the bait pellets happens after the hatching of albatross chicks, all pellets within six feet of each nest will be manually removed so the chicks cannot eat the pellets.

Aerial application is a more effective way to distribute bait pellets over the rough terrain of the island, and results in fewer disturbances to native seabirds and monk seals, officials said.

The draft assessment is needed to complete the Lehua Island Ecosystem Restoration Project.

Rabbits were successfully removed from Lehua in 2005-06 through hunting. They were considered a threat to plants.

"We had to give that time to make sure they were in fact gone, then we can concentrate on the rats," said Scott Fritz, DLNR's wildlife program manager. "Once the rabbits and rats are removed, we expect the vegetation to recover quickly on its own."