By Laura Zuckerman

SALMON, Idaho, Sept 3 (Reuters) - A heavy toll may be exacted on elk, moose and other wildlife whose habitat has been destroyed by wildfires that have charred hundreds of thousands of acres (hectares) of forests and grasslands across the U.S. Northwest this summer, wildlife managers said on Thursday.

Flames that in recent weeks have destroyed dozens of homes and prompted hundreds of residents to evacuate in Washington and Idaho have probably killed squirrels and small mammals unable to swiftly flee fire zones while fleeter creatures like deer likely escaped unharmed, wildlife biologists said.

Yet a season that has brought the largest wildfire in Washington history and a blaze in southwestern Idaho that killed more than two dozen mustangs pose challenges in the short term that may be offset by benefits in the long term, they said.

For example, a massive blaze in north central Idaho has consumed dense pine, fir and spruce canopies, which will ultimately allow in more light, rejuvenating grasses and forbs favored by ungulates like elk, said Idaho Fish and Game biologist Dave Koehler.

But destruction of crowded conifer canopies will be a hardship for owls and other birds of prey that thrive in such environments.

"All fires are not equal when it comes to how they impact wildlife," Koehler said. "What's good for one species may be a problem for another."

Prime rangelands in southwestern Idaho considered key habitat for the West's declining populations of greater sage-grouse - with U.S. wildlife managers to decide this month if the ground-dwelling birds will come under federal protections - were destroyed earlier this summer by a massive wildfire that also burned 27 wild horses to death and forced the euthanization of two other mustangs.

As U.S. land managers scramble to rehabilitate ground ravaged by the 280,000-acre (113,300-hectare) Soda Fire near Boise, wildlife officials in Washington were seeking to assess the impact of blazes in the eastern and north central parts of that state on animals' winter range.

With fires there still burning, biologists with the Washington Department of Fish and Wildlife already are evaluating how they might manage an influx of browsers like deer into commercial orchards and irrigated croplands in search of food.

"We might be seeing some major human-wildlife conflicts," said agency spokeswoman Madonna Luers. (Reporting by Laura Zuckerman in Salmon, Idaho; Editing by Dan Whitcomb and Sandra Maler)