Two whooping cranes have been reported so far in North Dakota during the endangered birds' fall migration, but neither sighting could be confirmed.

One bird was spotted by a hunter near Driscoll, and the other by a motorist on Interstate 94 about 10 miles west of Casselton. Both birds were seen Thursday.

The Driscoll-area bird probably was an albino sandhill crane, said Mike Szymanski, a migratory bird biologist with the state Game and Fish Department, who drove out to look but was unable to find the crane in question.

"The guy gave a pretty good description," Szymanski said. "Based on his description, it sounds like an albino sandhill."

Gregg Knutsen, a U.S. Fish and Wildlife Service biologist at Long Lake National Wildlife Refuge, said albino sandhills are rare, "but every year, there's one or two on the refuge." Sandhill cranes, which are gray, are smaller cousins of the mostly white whooping cranes.

The motorist spied what he identified as a whooping crane flying over him about 150 feet up.

"He gave a good description of a whooper," said Szymanski, who notified game wardens in the area about the report.

That bird was "quite a ways east" of whooping cranes' usual migration corridor, which is "approximately 100 miles either side of the Missouri River," added Knutsen, who is the state's whooping crane coordinator.

Knutsen expects to receive more reports of sightings in the coming weeks.

"We'll just have that many more people out there looking when the nonresident waterfowl season opener rolls around," he said. "There definitely will be more people with eyes looking around." The nonresident waterfowl season opens Saturday.

An estimated 234 rare whoopers, including 41 juveniles, are making their annual migration from their summer breeding grounds at Wood Buffalo National Park in Canada's Northwest Territories to their winter home in the Aransas National Wildlife Refuge and surrounding marshes on the Texas Gulf Coast. The journey is approximately 2,500 miles.

Wally Jobman, a USFWS biologist in Grand Island, Neb., and the coordinator of the migration monitoring project for the Wood Buffalo-Aransas flock, guesses the whoopers are still in Canada.

"After they leave Wood Buffalo, the birds spend a couple of weeks in central Saskatchewan feeding in small-grain fields and storing up energy for the trip."

He said the first few weeks of October should be prime migration time in North Dakota.

"In recent years, we've had warm falls, and that's why migration runs later," he said, "but if we get a good weather system out of Canada, it will push a lot of birds through North Dakota pretty quickly."

Whooping cranes, the tallest birds in North America at nearly 5 feet, are white with black wingtips that are visible only when they fly.

In flight, their long necks stretch straight forward, and their legs extend past their tails. They usually migrate in flocks of two to seven, and they sometimes are mixed in with sandhill cranes.

Pelicans, snow geese, swans, herons and egrets often can be mistaken for whooping cranes.

To report a whooping crane sighting, contact Knutsen at Long Lake NWR, 701-387-4397, by fax at 701-387-4767 or e-mail at gregg_knutsen@fws.gov or call Mike Johnson or Szymanski at NDGFD, 328-6300.

(Reach reporter Richard Hinton at 250-8256 or outdoors@bismarcktribune.net.)