Evolutionary Differentiation in Morphology, Vocalizations, and Allozymes Among Nomadic Sibling Species in the North American Red Crossbill (<i>Loxia curvirostra</i>) ... of California Publications in Zoology)

The highly variable North American red crossbill complex has presented one of the most controversial problems in avian systematics. Although crossbills wander nomadically and breed all year, they have not become homogenized in bill and body size. This study suggests that this crossbill complex contains several distinctive sibling species that breed sympatrically and show ecological differences.Groth, Jeffrey G. is the author of 'Evolutionary Differentiation in Morphology, Vocalizations, and Allozymes Among Nomadic Sibling Species in the North American Red Crossbill (Loxia curvirostra) ... of California Publications in Zoology)', published 1993 under ISBN 9780520097827 and ISBN 0520097823.