First Confirmed Minnesota Record of 'Appalachian' Red Crossbill

摘要

Red Crossbills have been under scrutiny by ornithologists for more than a decade. Specifically, researchers are wondering if we actually have ten species of Red Crossbills in North America. Studies of flight calls have hinted that crossbills may only respond to others of their own "type," which would isolate them reproductively from crossbills of different "types." Bill shapes in Red Crossbills also vary widely, each presumably adapted to extracting seeds from a specific type of conifer cone (pines, spruces, Douglas- firs, tamaracks, hemlocks). Research continues, but we birders probably need to start making an audio recorder part of our regular birding kit.