YOSEMITE NATIONAL PARK, Calif. (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 favor of the kind of discrete, sophisticated technology used by
spies and forensic scientists.
They hope to lessen human influence on this
subspecies of owls prized for the potential insights their survival offers into
habitat-specific evolution.
"Even if it takes only 15 minutes to trap a
bird, it's traumatic for them in the long term," said Joe Medley, a PhD
candidate in ecology at UC Davis who perfected computer voice recognition
software to track the largest of North America's owls. "With a population
this small, we want to err on the side of caution in terms of the methods we
use to get data."
Medley placed 40 data-compression digital audio
recorders around the mid-elevation meadows typically favored by the owl known
as Strix nebulosa Yosemitensis, hoping to identify them by their mating,
feeding and territorial calls.
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