Voice software helps study of rare Yosemite owls

YOSEMITE NATIONAL PARK, California (AP) - In the bird world, they make endangered condors seem almost commonplace.

The unique Great Gray Owls of Yosemite, left to evolve after glacial ice separated them from their plentiful Canadian brethren 30 millennia ago, are both a mystery and concern to the scientists charged with protecting them.

With fewer than 200 in existence in this small pocket of the Sierra Nevada, the slightest disturbances by humans can drive the extremely shy birds from their nests, disrupting sporadic mating cycles that ebb and flow annually depending upon food availability.

So this summer, researchers found a way to abandon their traditional heavy-handed trapping, banding and the blasting of owl calls in favour of the kind of discrete, sophisticated technology used by spies and forensic scientists.