RICHARD HINTON/Bismarck Tribune

Bismarck Tribune

A record hatch of 76 whooping cranes in Canada has wildlife biologists anticipating record high numbers of the endangered birds.

Production surveys on the Wood Buffalo National Park nesting grounds June 13-17 turned up 24 sets of twins among the chicks, Tom Stehn, the whooping crane coordinator for the U.S. Fish and Wildlife Service at Aransas National Wildlife Refuge, said in an e-mail sent Saturday.

"That's terrific. It's excellent news," said Gregg Knutsen, the state whooping crane coordinator for the USFWS who is a wildlife biologist at Long Lake National Wildlife Refuge.

The phenomenal chick hatch for North America's largest wild flock is coupled with chick booms in the two other whooping crane flocks. The first two wild whooping crane chicks in more than 100 years hatched in June at Necedah National Wildlife Refuge in Wisconsin. The parents were 4-year-old whooping cranes born in captivity at the Patuxent Wildlife Research Center and led in migration in 2002 behind ultralight aircraft from central Wisconsin to Florida.

Thirty chicks in the Wisconsin-Florida flock will be reintroduced into the population, and six chicks with valuable genetics will be kept in captivity for breeding, Stehn wrote.

And a nonmigratory flock in central Florida enjoyed a record production year. Seven chicks hatched there, and latest reports say five have survived.

Many of the large white birds in the Wood Buffalo-Aransas flock pass through through North Dakota semiannually as they make the 2,400-mile flight between their summer home that straddles the Alberta-Northwest border and their winter home in and around Aransas NWR on the Texas Gulf coast.

For that flock, the previous chick record was 66, hatched a few years ago, Stehn wrote.

"I am optimistic that survival of the chicks will be above average," Stehn added. He cited better than average water conditions and good weather as the reasons for his optimism.

"Based on the excellent production in June, approximately 230 plus whooping cranes are expected to reach Aransas in the fall, surpassing the record high of 220 present in the 2005-06 winter," Stehn wrote.

Canadian Wildlife Service researchers also located a record 62 nests during a May survey of the park, which Stehn described as a "virtual maze of small ponds." Sixty-one nests was the previous best.

Fifty-two of the 62 nests, or 84 percent, produced one or more chicks, Stehn wrote.

An estimated nine adult pairs, including two single adults, failed to nest but were present on their territories, compared to seven pairs that failed to nest in 2005. There are an estimated 71 breeding pairs in the Aransas-Wood Buffalo population.

An estimated 211 whooping cranes migrated this spring to Wood Buffalo. Five whooping cranes," one adult and five juveniles," died over the winter in Texas.

Three whooping cranes stayed at Aransas for the summer, including a 2004 chick that was injured in spring 2005 and has not migrated in 2005 or 2006.

"All three cranes look fine, but I always worry that the failure to migrate is an indication of a health problem," Stehn wrote.

(Reach outdoor writer Richard Hinton at 701-250-8256 or richard.hinton@bismarcktribune.com.)