Monday, October 25, 2010

Great Gray Owls in Yosemite

Here is a very nice story about the majestic owls, from the Modesto Bee.

An excerpt.

“FRESNO — For years, scientists thought logging, mining and development drove North America's largest owl out of Northern California forests and into Yosemite National Park.

“Scientists are rethinking that assumption. Genetic research shows the owls in Yosemite are a subspecies, a subtly different version of the great gray owl in North America.

“Scientists say the evidence suggests the Yosemite bird was stranded by vast ice fields and glaciers in the last Ice Age, evolving in isolation for more than 25,000 years.

“Such a discovery would make news about any Yosemite creature, but the great gray owl is a wildlife emblem, swooping down on rodents in wide mountain meadows.

“The great gray is an unmistakable yellow-eyed bird with a five-foot wingspan, but it is on the state Endangered Species Act list, and bird-watchers say it is a challenge to find one. Yosemite officials say there are about 150 great grays in the area.

“The Yosemite owl is not only genetically different from great gray owls in Oregon, Idaho and Canada, it also nests slightly differently and prefers a more narrow diet of rodents, scientists say.

“More than half of California's great gray owls are in the Yosemite region, and there are very few between the park and southern Oregon. Scientists say they still do not understand why there are only a few great grays in Northern California forests.

“It is not unusual to find species in the Sierra that were stranded during the last Ice Age, said wildlife ecologist John Keane, who led the research for the U.S. Forest Service Pacific Southwest Research Station.

“Researchers from the University of California at Davis also worked on the study, published in the July issue of the scientific journal Molecular Phylogenetics and Evolution. Scientists with the National Park Service, the state Department of Fish and Game and the U.S. Fish and Wildlife Agency were involved in the studies, which began six years ago.

“Great gray owls live at an altitude of 4,000 to 8,500 feet in the Sierra, but they migrate to lower elevations in snowy winters or when there is a lack of food.”