An immature bald eagle prepares to take off Thursday from a dead limb sticking from shallow water near where the Muddy and Virgin rivers meet in Lake Mead's Overton arm. Last year, 67 eagles were spotted on lakes Mead and Mohave. Photos by Gary Thompson. A juvenile bald eagle flaps its wings after taking off from Lake Mead's shoreline as a survey boat approaches Thursday. Life sciences biologist Jef Jaeger, left, and National Park Service biologist Mike Boyles peer through binoculars while resource management specialist Michelle Zuro scans the Lake Mead shoreline Thursday looking for bald eagles.

As seen through binoculars, the bald eagle with its wings stretching almost 6 feet from tip to tip soared above a sandstone cliff into a strong southwest wind that sent white-capped waves rolling up Lake Mead's Overton arm.

It was Thursday, the day the National Park Service sent eight teams of biologists and observers in boats on lakes Mead and Mohave to count the stately American icon.

"I got a bird dead ahead on that cliff," Jef Jaeger shouted to Ranger Chris Raynolds, the boat's skipper. "It's a bald eagle, a juvenile."

With a couple downward and upward strokes of its wings, the immature eagle with its head more gray-colored than snow-white appeared to hover along the skyline, 12 feet above the cliff.

For a bird that easily can fly more than 35 mph, it was a test to see whether its wings were more powerful than the 30 mph gust through which it was gliding. After gaining a slight advantage over a distance half the length of a football field, the young eagle finally surrendered, disappearing behind the cliff onto a more sheltered landing zone.

Perhaps it would have been better off to stay put like the adult bald eagle with its white head and white tail feathers that was seen a short time later standing tall on a sandy spit that jutted from a less windy stretch of the shoreline.

As the survey boat slowed down to approach it, the big bald eagle at first was reluctant to leave this more comfortable spot where it stood, watching for its prey -- a trout, striped bass, carp or even a coot -- to swim past. But it soon got wary, flapped its wings and flew off into the distance.

"That was cool," remarked Mike Boyles, a National Park Service resource management specialist who was the lead observer for the team.

The annual survey of bald eagles that migrate to the sprawling reservoir from frozen lakes and hunting grounds in the mountainous Northwest will be a piece of evidence in a nationwide effort to assess the bird's population.

If the trend of the past few years continues, federal wildlife biologists predict the bald eagle, which once struggled to rebound from the effects of pesticides in the 1960s, could be removed from the list of threatened species.

That is expected to happen next month, U.S. Fish and Wildlife Service officials have said.

Predating the Endangered Species Act of 1973, the bald eagle was declared an endangered species in 1967 for much of the United States except for areas north of the 40th parallel, especially Alaska. About half of all bald eagles in the world thrive there.

In 1963, only 417 nesting pairs were known to exist in the contiguous 48 states. The bald eagle's demise was blamed in part on habitat loss, but the biggest culprits were DDT and pesticides that contaminated prey the eagles ate, causing egg shells to thin and making the adults sick and infertile.

The service officially listed the bald eagle as endangered in 1976, which bolstered the government's attempt to protect its habitat and allow eagles to recover in the absence of pesticides that had been banned.

"Eagles and a lot of birds of prey are now doing better," Boyles said.

The bald eagle's status was changed from endangered to threatened in 1995.

Ever since, survey results including those from the winter counts in Lake Mead National Recreation Area, show the bald eagle is holding its ground.

Jaeger, a research assistant professor for the Public Lands Institute, a research arm of the University of Nevada, Las Vegas, points to data from surveys in the past few years.

Last year, 67 bald eagles were counted on lakes Mead and Mohave, the same number as in 2005. The tally was 60 in 2004; 68 in 2003; 79 in 2002, the highest on record; and 60 in 2001.

Jaeger said surveys conducted under a different format in the early 1990s in the recreation area posted numbers as low as in the 20s.

He said more uniform guidelines are being used to improve the integrity and accuracy of the counts. Closer attention is being paid to survey routes, weather conditions and the speed of observation boats.

"We're trying to coordinate eight teams across two lakes," Jaeger said. "You want to try to do it all at the same time, so we can minimize the double-counting error."

Under blustery conditions Thursday, the team on Lake Mead's Overton arm counted 14 bald eagles over about half the survey route. Choppy water made it difficult to nearly impossible for the team to keep a steady watch on some areas where more eagles had been recorded in previous years.

A practice count only a week before had turned up twice as many bald eagles.

Like on the Overton arm, some teams on other routes are expected to return soon under calmer conditions to complete the 2007 survey with more accurate data.

Nevertheless, Jaeger said preliminary results indicate the numbers are going to be on par with counts in recent years.

The ratio of more immature birds to adults is evidence that the bald eagles that come to Lake Mead are experiencing "a good recruiting period."

"It's encouraging," he said. "But because of the relative small sample size, I wouldn't go as far to say that the population is increasing."