Canada's endangered whooping crane population appears to be on the rebound, with Wood Buffalo National Park reporting a record high number of fledglings this year. At 63 new birds, this number beats the previous record set in 2006 of 49 birds.
“We were hoping for big numbers after we counted 98 nests this spring,” says Sharon Irwin, a resource conservation manager at the park. “It’s quite a jump from last year.”
Not only are there more fledglings this year, but the species productivity — a measure of new chicks per population size — was much larger than average. Four pairs of twins were also found — an exceptionally high number.
Irwin says this year’s number of fledglings is particularly high probably because of the large juvenile population born between 2010 and 2012. Those individuals have now reached breeding age and started their own nests. “You get years where we have fewer nests or fewer fledglings, but it definitely has been a steady upward climb,” she says.
In the spring, researchers do aerial surveys of the whooping crane’s habitat and make note of where nesting sites are found. Later in the summer, they survey the sites again and count the number of new fledglings.
The whooping crane was listed as endangered under the Species at Risk Act (SARA) in 2003, after decades of habitat loss and over-hunting had decimated their population. In the 1940s, their global population had dropped to just 21 individuals. Irwin estimates the Wood Buffalo National Park population – the only naturally wild population – has now climbed to over 400 individuals. In the fall, the whooping cranes will migrate south to Aransas Wildlife Refuge in Texas.
SARA’s long term recovery goal is to establish 1,000 whooping cranes by 2035. “There’s still a ways to go, but we’re definitely getting closer to numbers that will save them from disaster,” says Irwin.
To further their conservation research, 10 fledglings have been tagged with telemetry bands to track the birds on their migration route and assess potential risks they might face.