California spotted owl habitat characteristics and use

Abstract

California spotted owls (Strix occidentalis occidentalis) establish large home ranges averaging about 1279 ha (3,160 ac) (table 3-1), and within these home ranges individual owls select habitat at different scales, depending on their activity. At the smallest spatial scale, the nest tree, it appears there is very limited flexibility in the requirements. However, as owls select habitat at larger scales and for different activities, from nest stand to core area to foraging habitat, there is greater variability in the habitat characteristics, which suggests greater flexibility in selection. Currently, researchers have not established definitions of the size of a nest stand or core area, nor have they reached consensus on how to calculate these aspects of owl habitat. This is at least partially because each researcher uses a certain method to estimate the nest stand or core area that is relevant only to the particular question they are investigating, and as those questions differ between research projects, the methods and definitions for those terms also differ. This chapter presents the current research describing spotted owl habitat characteristics and is organized by spatial scale, starting with the nest tree, followed by the nest stand, core area, foraging habitat, prey habitat, and finally the home range. Next is a brief assessment of the current research on the effects of fire on spotted owl habitat, and followed by relevant management implications.

Parent Publication

• The California spotted owl: current state of knowledge

Citation

Roberts, Susan L. 2017. California spotted owl habitat characteristics and use. In: Gutiérrez, R.J.; Manley, Patricia N.; Stine, Peter A., tech. eds. The California spotted owl: current state of knowledge. Gen. Tech. Rep. PSW-GTR-254. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station: 49-73. Chapter 3.