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Geographic patterns in relative abundances and population trends of breeding and wintering loggerhead shrikes in North America

Held 11-15 January 1993, Archbold Biological Station, Lake Placid, FL.
By:
, , and
Edited by:
Reuven Yosef and Fred E. Lohrer

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Abstract

In North America, the Breeding Bird Survey and the Christmas Bird Count provide data that are collected at sites visited each year, and the site-specific data can be placed in a Geographic Information System and smoothed to produce contour maps of relative abundance and trend for the United States and southern Canada. We develop these contour maps for Loggerhead Shrike (Lanius ludovicianus) data from both surveys, and compare the patterns derived from each survey to evaluate the consistency of trends and relative abundances within physiographic strata. Patterns in relative abundance seem to be associated with strata, especially in the breeding season, but trends are often heterogeneous within strata. Because of limitations of the surveys and observed geographic patterns of shrike trends in the survey data, we suggest that there is no natural scale for the analysis of shrike-habitat associations.

Additional Publication Details

Publication type:
Book chapter
Publication Subtype:
Book Chapter
Title:
Geographic patterns in relative abundances and population trends of breeding and wintering loggerhead shrikes in North America
Year Published:
1995
Language:
English
Contributing office(s):
Patuxent Wildlife Research Center
Description:
ix, 343
Larger Work Type:
Book
Larger Work Subtype:
Other Government Series
Larger Work Title:
Shrikes (Laniidae) of the World: Biology and Conservation. Proceedings of the First International Shrike Symposium
First page:
128
Last page:
141