Maturation and Variation of Head Characteristics in Sandhill Cranes

摘要

We evaluated eye color, bill color, and head plumage characteristics in 836 known-age Sandhill Cranes (Grus canadensis) captured in Florida Between 1974 and 1995. Eighty-three birds were re- Captured 1-16 years later. There were noticeable vari- Ations in eye color and head plumage among individ- Uals and between birds 20 months or less of age and Those 21 months and older. These variations may be Representative of the relatively high genetic diversity In Sandhill Cranes and be criteria for mate selection. Received 10 August 1997, accepted 29 Oct. 1997.