The babies will soon be spreading their wings and on their way.
Whooping crane chicks in the nesting territory of the northeastern corner of Wood Buffalo National Park are fattening up and growing more each day in order to begin their long migration back to the wild flock’s wintering grounds in Texas later this month.
Members of the Canadian Wildlife Service (CWS) and Parks Canada flew over the area two weeks ago in a joint survey of the nesting productivity of whooping cranes in the park, a flock numbering around 300.
They found 28 families with one chick each this year.
CWS and Parks staff did a similar survey in July to count the number of nests and found a total of 74.
“The objective of this August survey is to go back to those nests and search the area around them for whooping crane families, which consist of two parents and up to two chicks,” Mark Bidwell, a species at risk biologist with Environment Canada who was on the survey, told The Journal. “We are trying to find out how many of those 74 nests were successful at producing at least one chick.”
This figure compares to a total of 31 families counted in 2012, two of which successfully produced two babies for a total of 33 chicks.
“It’s a reduction in the number of chicks from 47 per cent breeding success in 2012 to 38 per cent this year,” Bidwell, who has been doing the survey for three years, said. “That means 38 per cent of the nests hatched a chick that survived to this stage.”
While the number may seem low, it’s not a reason for concern over the population that teetered on the brink of extinction in the 1940s. Whoopers are now protected by the Migratory Birds Convention Act and the Species at Risk Act.
Experts expect one of every two nests to have a chick by August, Bidwell said.
“Last year’s figure of about 50 per cent breeding success is pretty much the long term average. We don’t get too concerned about one particular year…What we would be concerned about is if we saw a reduction in the number of chicks over a number of years, and we haven’t seen that,” he said.
According to Bidwell, this is a “small reduction” and they have “no evidence yet to suggest there is any long term decline in chick productivity.”
While a number of wildfires have ravaged the park this summer, the crane territories have not been affected, Bidwell said, whereas last year, one of the breeding areas was impacted by fire.
Parks and CWS staff have no evidence to suggest wildfires are interfering with the birds’ nesting productivity, he added.
Growing into North America’s largest birds
The chicks are currently about two thirds the size of their parents, Bidwell said.
“They have to grow to almost full size by the time they migrate to Texas. They’re rusty brown coloured, a contrast to the white adults with the black wing tips and red on their heads. They’re really beautiful together. The young molt over the winter and arrive back in Wood Buffalo with white feathers,” he said.
The next generation’s main task this month is to grow quickly.
“They need to find food and avoid sources of danger like predators. So they spend all of their time in very close company of their parents, who are quite protective,” Bidwell said.
That intensely protective instinct is one of the reasons the survey is conducted from at least 300 metres above ground, though the birds do look up at the plane as it passes by.
“They absolutely notice us. They will sometimes walk away slowly, but they do not exhibit protective behaviour as they would if we were on the ground. We’re causing the least amount of disturbance as possible.”
The whoopers begin trickling out of the park in late August, spending four to six weeks in central Saskatchewan before flying to the Aransas National Wildlife Refuge in Texas.
The conservation of whooping cranes is a “real success story” for Canada and the United States, Bidwell said.
“Even though numbers are still small, there has been almost exponential growth since the 1930s,” he said. “Whooping cranes are an iconic species…and staff at both agencies (CWS and Parks) are committed to building a partnership to improve research, monitoring and increase public awareness about the birds.”1 comment