Just in time for America's birthday, Minnesota will launch a new generation of America's national symbol.

The state's thriving bald eagle population is in the midst of nesting season, and the birds hatched this year should be ready to fledge — or fly from the nest — right around July 4.

"Our bald eagle population is doing very well. We have the highest population of bald eagles in the Lower 48," said Lori Naumann, a representative of the nongame wildlife program of the state Department of Natural Resources (DNR).

Naumann said Minnesota has about 9,800 pairs of bald eagles, with the birds having made a remarkable comeback from 30 or so years ago, when they were considered endangered. When the bald eagles were scarce, the DNR regularly surveyed breeding areas to keep track of the number of nests.

"We stopped doing surveys because we know the population is healthy," she said.

Naumann said the eagles' recovery has been greatly aided by the tax checkoff program for the state Nongame Wildlife Fund. Minnesotans can make a tax-deductible donation to the fund by checking a box on their property or income taxes.

Eagles typically nest from March through July, returning to the same nest year after year. Even during the off months, the eagles often will return to do "nestorations," bringing in new sticks to repair or add to the nest. Some pairs have more than one nest, alternating them year to year.

Some bald eagles stay in Minnesota year-round, Naumann said.

"If they're in an area where they can find open water, they can find food," she said. "They can take squirrels and rabbits and rodents. They'll also find a lot of roadkill — eagles will eat any kind of roadkill."

Voyageurs National Park in northern Minnesota recently closed a handful of campsites to protect eagles nesting nearby, but Naumann said such action usually isn't necessary.

"Some of them are vulnerable when they are nesting," she said. "However, we have found that some of it depends on the birds — where they grew up, how exposed they were to human activity. Some are more tolerant than others."

Bald eagles are thriving in the Twin Cities area, too. Naumann said there were more than 60 nests in the seven-county metro area the last time the DNR counted them in 2005.

With a healthy population, the department hasn't done a count since.

John Reinan • 612-673-7402