Meeting Abstract
Golden-winged Warblers are migratory birds experiencing varied regional population trends that are not explained by breeding-grounds factors. No information exists on nonbreeding distributions, migration routes, or timing of migration among populations, and factors outside the breeding period may influence population trends. We tracked annual movements of Golden-winged Warblers from 3 North American breeding locations experiencing varying population trends using geolocators from 2013-2015 to investigate the potential for nonbreeding-site factors to influence breeding populations. We analyzed geolocator data using the template-fit method, which is more accurate than the more commonly used threshold method. Geolocator-marked Golden-winged Warblers exhibited significant isolation among populations during the nonbreeding period and during migration. Golden-winged Warblers from Minnesota, USA migrated to areas in Central America from southern Mexico to central Nicaragua; warblers from Tennessee, USA migrated to areas along the border of northern Colombia and Venezuela; and warblers from Pennsylvania, USA migrated to areas farther east in central Venezuela. Golden-winged Warblers from these three breeding populations exhibited essentially no effective overlap during the nonbreeding period. Fall migration routes around the Gulf of Mexico were population specific, whereas spring migratory routes were more varied and overlapped among populations. Our results reveal nearly complete temporal and geographic isolation among three populations of Golden-winged Warblers throughout the annual cycle resulting in opportunities for population- and site-specific factors to differentially influence populations.
