Local weather, regional climate, and annual survival of the northern spotted owl

The Condor
By: , and 

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Abstract

We used an information-theoretical approach and Cormack—Jolly—Seber models for open populations in program MARK to examine relationships between survival rates of Northern Spotted Owls and a variety of local weather variables and long-term climate variables. In four of the six populations examined, survival was positively associated with wetter than normal conditions during the growing season or high summer temperatures. At the three study areas located at the highest elevations, survival was positively associated with winter temperature but also had a negative or quadratic relation with the number of storms and winter precipitation. A meta-analysis of all six areas combined indicated that annual survival was most strongly associated with phase shifts in the Southern Oscillation and Pacific Decadal Oscillation, which reflect large-scale temperature and precipitation patterns in this region. Climate accounted for a variable amount (1–41%) of the total process variation in annual survival but for more year-to-year variation (3–66%) than did spatial variation among owl territories (0–7%). Negative associations between survival and cold, wet winters and nesting seasons were similar to those found in other studies of the Spotted Owl. The relationships between survival and growing-season precipitation and regional climate patterns, however, had not been reported for this species previously. Climate-change models for the first half of the 21st century predict warmer, wetter winters and hotter, drier summers for the Pacific Northwest. Our results indicate that these conditions could decrease Spotted Owl survival in some areas.

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Publication type Article
Publication Subtype Journal Article
Title Local weather, regional climate, and annual survival of the northern spotted owl
Series title The Condor
DOI 10.1525/cond.2011.100118
Volume 113
Issue 1
Year Published 2011
Language English
Publisher Oxford Academic
Description 18 p.
Larger Work Type Article
First page 159
Last page 176
Country United States
State Oregon, Washington
Other Geospatial Pacific Northwest
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