By MIKE CORN

mcorn@dailynews.net

RUSSELL SPRINGS -- After spending eight days -- or rather nights -- afield under cover of darkness, results of the annual fall black-footed ferret survey are expected to break all records.

Exactly how many ferrets were captured over the course of the past two weeks is still uncertain, as the survey broke up as the sun climbed above the horizon this morning.

Over the next week, U.S. Fish and Wildlife biologist Dan Mulhern will review and assemble the information collected to determine how many ferrets were captured, vaccinated and chipped for future identification.

The surveys, conducted in the spring and fall, are part of a reintroduction project by the FWS, hoping to bring the animal back from the brink of extinction. Ferrets, in fact, were first thought to already be extinct, until a population of 18 were found in Wyoming.

Since then, intensive efforts have boosted the population.

Despite that, the ferret population is still well below thresholds that would allow it to go off the endangered species list.

In March, when the last survey was conducted, 29 ferrets were captured.

This time around, said Larry Haverfield, on whose land an entourage of searchers are criss-crossing the countryside using spotlights to find the distinctive emerald green eyes of the ferrets, the capture rate has been extensive.

Twice this week alone, there have been two 11-ferret nights -- nights when 11 ferrets were captured during the nighttime shift.

"With 11 per night, things are looking pretty good," Haverfield said.

Haverfield has been relaying messages between searchers scouring the landscape on the 16,800-acre Smoky Valley Ranch owned by the Nature Conservancy, where ferrets have been released. Ferrets were also released on what is known as the Haverfield-Barnhardt complex, covering nearly 10,000 acres.

"It looks like we will run over the March numbers pretty good," Haverfield said of the surveys, even though final numbers won't be known until next week.

A new batch of ferrets -- 14 in all -- have been released this fall on Nature Conservancy land, Mulhern said.

They had been bound for release in Canada, which had its first reintroduction just last fall. Despite the new project, it's already seeing the effects from sylvatic plague, a flea-borne disease that is deadly to both ferrets and prairie dogs, upon whom the ferrets depend on for food and shelter.

Another 18 ferrets are expected to be released later this fall on the Haverfield-Barnhardt complex, considered to be the top small reintroduction site in the nation, primarily because there's been no incidence of sylvatic plague.