Characteristics of Old-Growth Forests Associated with Northern Spotted Owls in Olympic National Park

Abstract

The relationship between northern spotted owls (Strix occidentalis caurina) and old-growth fores is well established, but there are few studies indicating which particular characteristics of these forests are most important to spotted owls. Thus, we compared characteristics of forests at owl response and non-response sites across Olympic National Park to identify the specific features which best predict daytime presence of northern spotted owls in relatively pristine forest. At 32 owl response sites and 230 non-response sites we measured 9 structural and species composition variables thought to be important to spotted owls. Based on these variables, we used stepwise logistic regression to develop models predicting the presence or absence of spotted owls