The Northern spotted owl, Strix occidentalis caurina, (NSO) is the flagship threatened species of the Pacific Northwest. Federally listed under the Endangered Species Act in 1990, the NSO continues to decline at a rate of about 4% throughout its range. Despite the fact that the NSO is one of the best-studied wild vertebrate species in the world, the relative importance of the threats that it faces remain controversial.
Our Center developed measures to help assess the relative impacts of pressures such as barred owl invasion, habitat loss and anthropogenic disturbance in NSO. We developed non-invasive fecal hormone measures of physiological (glucocorticoids) and nutritional stress (thyroid hormones) and reproductive activity (sex steroids) in NSO. We applied these tools to document impacts of off-highway vehicle and road exposure on the NSO and to further improve survey techniques for Northern spotted owls and barred owls (BO).
For more information regarding the Impacts of vehicle and road exposure to NSO, click here.
For more information about Improving the survey techniques of NSO and BO, click here.