The Idaho Fish and Game Commission in May approved a five-year plan to kill and haze American white pelicans in southeastern Idaho to protect sport fish and Yellowstone cutthroat trout populations. The plan calls for shooting some pelicans and applying oil to eggs to suffocate the embryos.

Pelicans are protected under federal law, so anything to cut their numbers requires U.S. Fish and Wildlife Service approval.

"We didn't feel the management plan had enough data in it right now to issue the permits required," said Brad Bortner, the Fish and Wildlife Service's migratory birds chief in Portland, Ore. on Wednesday.

Idaho wildlife officials took exception to characterizations of their proposal as a "pelican eradication program" by wildlife officials in Utah

"Absolutely not," said Jeff Gould, chief of Idaho's Bureau of Wildlife. "It's a management plan for pelicans, with the primary goal of reducing impacts to fish."

Gould expects to meet with federal Fish and Wildlife officials later in July to discuss their questions about Idaho's plan, as well as what additional scientific justification will be needed to obtain permits to proceed with management of the big birds.

Pelicans at the Blackfoot Reservoir colony have increased from 1,400 breeding birds in 2002 to 2,400 breeding birds in 2008, while a colony on Lake Walcott on the Snake River increased from about 400 breeding birds in 2002 to more than 4,000 breeding birds.

The agency's plan calls for reducing bird numbers by more than half, while still maintaining a viable population: 700 breeding birds at the Blackfoot Reservoir and 2,100 in Lake Walcott.

Two Fish and Wildlife Service offices - in Oregon and in Utah - panned Idaho's plan, saying that implementing the proposal would undo pelican conservation accomplishments from the last 25 years and any damage could be irreversible.

"Given the conservation status assigned by Idaho and other western states, and given the threats to the species, we believe it is unwise to begin a pelican eradication program," wrote Larry Crist, Fish and Wildlife Service's Utah field supervisor.

"Lethal take of pelicans would not be reversible and it could take years for the local population to recover," he wrote.

Federal managers suggested Idaho instead construct in-stream structures, permanent wire arrays and plant streamside vegetation to discourage pelicans that prey on Yellowstone cutthroat trout, especially in low water years when those swimming upstream are particularly vulnerable.

They also said Idaho's plan failed to take into account how historic water levels in the Blackfoot Reservoir played a role in reducing Yellowstone cutthroat trout numbers. More than 4,700 spawning cutthroats were counted in 2001; the number dropped to just 14 in 2005.

But federal officials pointed out the crash following 2001 came after river discharges during spawning, while trout increased substantially in 2008 after several years of higher river flows.

Pelicans likely arrived in Idaho before white settlers, though the creation of reservoirs for farm irrigation like on the Blackfoot River in the early 1900s produced ideal island habitat for the ground-nesting birds. Some anglers complain the birds eat too many sport fish, though Fish and Game's own plan concedes 90 percent of their diet is composed of non-game fish like chubs.

Idaho can continue to haze pelicans that may be eating cutthroat trout. And for a fourth year, Fish and Wildlife gave state managers permission to kill up to 50 pelicans, though only for scientific analysis of things like their diet, not to control their numbers.

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