Northern News Services
Published Monday, September 10, 2007
FORT SMITH - A record number of whooping crane chicks born this year in Wood Buffalo National Park did not translate into a record number of the endangered birds surviving the summer.
A flock of whooping cranes nest each year in Wood Buffalo National Park. - photo courtesy of Wood Buffalo National Park
In a June survey, 84 chicks were spotted in 65 nests, which was also a record.
However, another survey in August found that just 40 of the chicks survived the summer.
"I'm disappointed, but it's not unexpected," said Brian Johns, a biologist and whooping crane expert with the Canadian Wildlife Service in Saskatoon.
Johns blames the low survival rate on dry conditions in some areas of the park.
Johns said conditions were especially dry along the Sass River, which has the second largest whooping crane nesting area in the park.
"Not a lot of the young survived in that area," he said. Only four chicks survived from 16 nests.
Conditions were not as dry along the Klewi River, which is the largest nesting area, and along the Nyarling River.
"If the wetlands are too dry, the whooping cranes have to do a lot of travelling to wetlands with food in them," he said, explaining the birds feed on such things as dragon fly larva, frogs, small fish, snails and leaches.
The adults and the chicks walk to the new areas, he said. "That's when they encounter predators."
Those predators include wolves, foxes and mink.
The 40 surviving chicks are now at flying age, Johns said "The chances of surviving and getting to the wintering grounds are pretty good."
The flock migrates to Texas and will leave the park in late September or early October.
Of the 40 young birds, Johns hopes about 35 will avoid power lines and other hazards during migration to make it to Texas.
Forty chicks is the second highest number ever to survive the summer. Last year, 49 were found in the August survey and 45 made it to the wintering grounds.
The previous records were set last year when there were 62 nests and 72 chicks at the beginning of the summer.
The overall population of whooping cranes in the world has been growing recently.
Last winter's official count found 237 in the Wood Buffalo flock, 50 in Florida, 80 in Wisconsin and 145 in captivity. However, a severe storm last February in Florida killed 17 birds which had migrated from Wisconsin.