Threats to the northern spotted owl

The iconic northern spotted owl was first listed as threatened in 1990, which led to 80% reduced logging in federal forests. Timber interests and conservatives have cited the northern spotted owl as an example of excessive or misguided environmental protection, but many environmentalists view the owl as an indicator species, whose preservation has created protection for an entire threatened ecosystem. One often overlooked factor in species extinction is man-made noise. Roads and traffic noise are a growing concern to wildlife managers. From 2005 to 2008 we conducted a large-scale field study to quantify the effects of off-highway vehicle exposure on northern spotted owls in northern California near the southern limit of their range.  The study found that owls close to noisy roads fledged significantly fewer young than those near quiet roads, indicating that routine traffic exposure may decrease the owls’ reproductive success over time. Habitat conservation measures on federal lands have been working well in protecting the northern spotted owl, but manmade noise and competition from the non-native barred owl continues to negatively impact spotted owl populations.

Hayward, L.S., A. Bowles, J.C. Ha And S.K. Wasser. Impacts of acute and long-term vehicle exposure on physical and reproductive success of the northern spotted owl. Ecosphere. 2 (6) Article 65:1-20 (On-line journal of the Ecological Society of America.) 2021.