Calgary Herald May 13, 2011
"They do breed and fend for themselves, and get to the point where they migrate," said zoo director Jake Veasey.
But Veasey said researchers are still trying to pinpoint why only 13 per cent of the endangered birds they tag during the breeding season return the following year.
They could be finding new homes in British Columbia or in the United States, or something could be threatening their habitat, he said.
In the last 30 years the national population of burrowing owls has dropped dramatically, from 3,000 pairs to fewer than 800 pairs.
Potential reasons range from the lack of burrows created by other burrowing animals such as marmots and ground squirrels, to climate change and environmental contaminants.
Since 1992 the breeding program has released 1,164 pairs into the wild
Hancock Wildlife Foundation