A recent determination that the great gray owls that reside in and around Yosemite National Park are a distinct subspecies is additional evidence that national parks are great, and vital, preserves for wildlife. And it's proof that we still have much to learn about what resides in the parks.
Standing about 2 feet tall and with a wingspan approaching 5 feet from wingtip to wingtip, these predators long have been listed as a California State Endangered Species. The roughly 150 great gray owls that live within Yosemite are thought to represent 65 percent of the state's entire great gray owl population, according to a release from park officials.
Yosemite counts more than 400 species of animals, including 165 resident and migratory birds. The abundant diversity in wildlife is due to the park’s natural habitats and ecosystems that remain largely intact, biologists say. Those habitats range from thick wooded foothills to expanses of meadows and alpine terrain found in the park’s higher elevations.
While great gray owls also can be found in Europe and Asia, research into the species that resides in the park gained priority for scientists as evidence showed that the Sierra Nevada is home to a genetically distinct population of great gray owls, compared to other great gray owls found in North America, Asia, and Europe. Prior scientific research on great gray owls shows that only two other subspecies have been recognized: Strix nebulosa nebulosa in North America and Strix nebulosa lapponica in Europe and Asia.
Once researchers determined that the great gray owls in Yosemite were a distinct subspecies from other populations, they attached a new name to them: Strix nebulosa yosemitensis.
According to park officials, along with noticing genetic differences, scientists have also observed behavioral differences in the Yosemite subspecies. These include differences in migration patterns, prey preference, and nest site selection. Each of these characteristics shows that the Sierra Nevada population of great gray owls has been isolated from other populations for an extensive period of time, they say.
“Future research in Yosemite National Park will allow us to identify specific characteristics of the great gray owls in the park, and to further study their habitat. National parks like Yosemite, that provide nearly intact ecosystems, are critically important to both identify new species of plants and animals and to provide a laboratory in which to conduct scientific study,” said Niki Nicholas, the park's chief of resources management and science.
Future research on the great gray owl in Yosemite is expected to help develop a genetic technique to identify individual owls from their molted feathers. This non-invasive research method would allow scientists to study survival rates, reproduction patterns, and other important information through the DNA found in the collected feathers. Additionally, this research method would mitigate negative impacts on the sensitive great gray owl population in the park.