The yellow-throated warbler is primarily a southern and central US breeder nesting in deciduous forests. However, in some of their populations in the northeastern edge of their range and in the panhandle of Florida they primarily occupy pine forests where they are competing with pine warblers for food. In an example of rapid evolutionary change, within the last 50 years these populations of yellow-throated warbler’s beaks and skulls have grown 10% longer than their deciduous relatives. The increased beak length has enabled them to coexist with the pine warblers, allowing them to probe open pine cones for insects that the pine warblers cannot reach.
Photo © copyright by Toby Skov.