Loggerhead Shrike Seasonal Abundance over Seventeen Years on a Transect in the Southern Sierra Nevada Foothills, California

Abstract

We used data from 17 years of surveys along a transect in the Sierra Nevada foothills in eastern Merced and western Mariposa counties of California to assess changes in the abundance of the Loggerhead Shrike (Lanius ludovicianus) in this area. We found significant seasonal changes with much smaller numbers present in the breeding season than in the non-breeding season. The data were not sufficient to allow an assessment of breeding or non-breeding abundance trends over the full period.