Fidelity and Interseasonal Movements of Purple Finches (Carpodacus purpureus (Gmelin)): Analysis of Band Re-encounter Data

Abstract

The Purple Finch (Carpodacus purpureus (Gmelin)) is a migratory fringillid breeding across the northern co- niferous forests of North America. Although irruptions occur, little information has been gathered on the movements of individual birds. We used the 19,893 re-encounters of banded birds in the Bird Banding Laboratory database to identify patterns of movements and to examine wintering and breeding site fidelity. After normalizing the data for banding effort, we found that birds banded in the northeastern United States tended to move along the Atlantic Seaboard. Most birds banded in the upper Mid-west also moved along a north-south axis. Purple Finches west of the Sierra Nevada and Cascade Mountains in the far west rarely move east of those mountains. Throughout the range of the species, most movements tend to be along the north-south axis. The re-encounter data indicated a strong level of breeding site and wintering site fidelity with evidence of some year-round fidelity. Analysis of re-encounters as a function of season of banding and season of re- encounter demonstrated that birds stayed close to their breeding grounds during the fall before leaving for their wintering areas. Birds departed from the wintering areas early in the spring.