The Great Gray Owl has been on the California state Endangered Species List for some time. Current estimates say there may be fewer than 300 of these marvelous birds in the entire state. Their modern range is limited. They may once have lived in the Sacramento River Valley but they are now limited to relict populations in scattered bits of suitable habitat in the central Sierra from 1800 to 7000 feet elevation. One recent study of Yosemite, where the birds were first confirmed nesting in 1914, found less than 10 percent of that giant park is suitable GGO habitat. There is also a tiny sliver of the Oregon population that dips across the border into Modoc County north of Alturas. Human alteration of the habitat has not been positive for the Great Gray Owl. Now climate change just adds stress and more uncertainty about their ability to survive. Vehicles and Great Horned Owls are lead natural enemies. Introduced West Nile Virus is a potential game-ender though so far there is no evidence it has struck California’s population. An Oregon owl in the northeastern part of the state died of West Nile last year. The GGO is highly susceptible to the disease.
The most crucial and thorough study of Great Gray Owls ever done anywhere in North America is now completed and has been presented to the California government and the public. It calls for serious action to help this species survive. You can click here to read the report and its conclusions.
The research also shows that the central California population has been genetically cut off from more northerly populations for over 25,000 years and should be given sub-species status which in turn could allow federal designation as an endangered species. None of the breeding birds along the Pacific Slope south of Canada are migratory. The Yosemite owls will never meet an Oregon cousin.
OREGON AND WASHINGTON GGOs
Union County and Jackson County in Oregon may each have as many GGOs as the entire state of California. Yet it is unlikely there are as many of the birds in Oregon as there are people in McMinnville where I live (33,000). We should be aware of what is recommended in California and what gets done and what effects that may have.
Washington State has few Great Gray Owls apparently and only a handful of nesting records have ever been confirmed. The first one in the state did not come until 1991.