The importance of mature conifers to red crossbills in southeast Alaska

• Published in: Forest ecology and management Vol. 102; no. 2; pp. 167 - 172
• Main Authors: Holimon, William C, Benkman, Craig W, Willson, Mary F
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 23.03.1998; Elsevier
• Subjects: Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Cone crops; Conservation, protection and management of environment and wildlife; Foraging behavior; Fundamental and applied biological sciences. Psychology; Loxia curvirostra; Parks, reserves, wildlife conservation. Endangered species: population survey and restocking; Picea sitchensis; Tsuga heterophylla; Alaska; United States; North America; America; Cone crops; Loxia curvirostra; Tsuga heterophylla; Foraging behavior; Picea sitchensis; Feeding behavior; Endangered species; Seed production; Granivorous; Vertebrata; Animal plant relation; Softwood forest tree; Gymnospermae; Coniferales; Spermatophyta; Developmental stage; Aves
• ISSN: 0378-1127; 1872-7042
• DOI: 10.1016/S0378-1127(97)00157-6

Red crossbills ( Loxia curvirostra) in southeast Alaska feed mostly on seeds in the cones of western hemlock ( Tsuga heterophylla) and Sitka spruce ( Picea sitchensis). During a year of poor cone production, red crossbills did not forage in young stands. Within mature stands, crossbills tended to forage preferentially on trees with large cone crops. These favored trees were also the larger and older trees because cone production increases with tree size. The avoidance of young stands is especially pronounced during poor seed years and may be related to the absence of mature trees containing numerous cones with many seeds. We suggest that mature stands are critical for maintaining crossbill populations and possibly other conifer seed-eating species.