Threats to Northern Spotted Owls

The biggest threat to the northern spotted owl is loss of old growth forest habitat as a result of logging and forest fragmentation. These threats are made even greater by natural disasters, such as fire, volcanic eruptions and wind storms.

These spotted owls are also affected by increasing barred owl populations. The range of barred owls has been expanding from the eastern United States into western Canada, the Pacific Northwest and northern California. Barred owls displace resident spotted owls and often breed with them, creating hybrids.

Climate change is projected to bring wetter winters and drier summers to northern spotted owl habitat. Summer drought stress could increase the rates of insect outbreaks and forest fires in the old-growth forests that the owls depend on.

Finally, higher temperatures and drought conditions favor diseases like the mosquito-borne West Nile virus. West Nile develops more rapidly at higher temperatures, increasing the likelihood of transmission. Drought conditions also concentrate birds at remaining water sources, making them an easier target for disease-carrying mosquitoes.