Record Details

Survival and Home-range Size of Northern Spotted Owls in Southwestern Oregon

ScholarsArchive at Oregon State University

Field Value
Title Survival and Home-range Size of Northern Spotted Owls in Southwestern Oregon
Names Schilling, Jason W. (creator)
Dugger, Katie M. (creator)
Anthony, Robert G. (creator)
Date Issued 2013-03 (iso8601)
Note This is a scanned version of a published article. The original can be found at: http://www.raptorresearchfoundation.org/publications/journal-of-raptor-research. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work.
Abstract In the Klamath province of southwestern Oregon, Northern Spotted Owls (Strix occidentalis caurina) occur in complex, productive forests that historically supported frequent fires of variable severity. However, little is known about the relationships between Spotted Owl survival and home-range size and the characteristics of fire-prone, mixed-conifer forests of the Klamath province. Thus, the objectives of this study were to estimate monthly survival rates and home-range size in relation to habitat characteristics for Northern Spotted Owls in southwestern Oregon. Home-range size and survival of 15 Northern Spotted Owls was monitored using radiotelemetry in the Ashland Ranger District of the Rogue River–Siskiyou National Forest from September 2006 to October 2008. Habitat classes within Spotted Owl home ranges were characterized using a remote-sensed vegetation map of the study area. Estimates of monthly survival ranged from 0.89 to 1.0 and were positively correlated with the number of late-seral habitat patches and the amount of edge, and negatively correlated with the mean nearest neighbor distance between late-seral habitats. Annual home-range size varied from to 189 to 894 ha (x̄ =  576; SE  =  75), with little difference between breeding and nonbreeding home ranges. Breeding-season home-range size increased with the amount of hard edge, and the amount of old and mature forest combined. Core area, annual and nonbreeding season home-range sizes all increased with increased amounts of hard edge, suggesting that increased fragmentation is associated with larger core and home-range sizes. Although no effect of the amount of late-seral stage forest on either survival or home-range size was detected, these results are the first to concurrently demonstrate increased forest fragmentation with decreased survival and increased home-range size of Northern Spotted Owls.
Genre Article
Topic Northern Spotted Owl
Identifier Schilling, J., Dugger, K., & Anthony, R. (2013). Survival and home-range size of northern spotted owls in southwestern oregon. Journal of Raptor Research, 47(1), 1-14.

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