ORNAMENT MORPHOLOGY AND SOFT TISSUE AND SKELETAL CORRELATES IN ALEUTIAN CACKLING GEESE (BRANTA HUTCHINSII LEUCOPAREIA).
Matthew D. Delgado; Humboldt State University; 4098, Eureka, CA, 95503; (707) 845-7371; Matthew.Delgado@Humboldt.edu; Jeffrey M. Black
Aleutian cackling geese (Branta hutchinsii leucopareia) display ornaments on their heads and necks during intraspecific interactions. We determined whether the morphology of these ornaments in Aleutian geese (n = 50) was correlated to indices of individual quality (e.g. honest signal and badge of status theory). We also examined the linear relationship between wing spurs, ornament morphology, and indices of individual quality. The smoothness of the lower neck ring ornament was positively associated with gizzard mass in both sexes. Males showed a uni-modal distribution of this trait, whereas females were multi-modal. Wing spur size was positively correlated to heart size in both sexes, and positively correlated with cheek patch area in male geese. Ornament irregularities, which are tied to an individual's ability to precisely deposit melanin in feathers and environmental wear, may reflect an individual's health as influenced by parasite load, food acquisition, and/or metabolic stress from migration. Ornament attributes such as smoothness and size may signal vital information to conspecifics in Aleutian cackling geese.
Poster Session