2011/04/01 by Shane P. Mahoney, Jackie N. Weir, J. Glenn Luther +2 · 1 citation
Environmental Science · Biochemistry, Genetics and Molecular Biology · #Wildlife Ecology and Conservation #Marine animal studies overview #Genetic and phenotypic traits in livestock #Antler #Abundance (ecology) #Ecology #Biology #Population #Population size #Geography #Demography
paper · pdf · doi:10.7557/2.31.1.1917
openalex publication_date 2011/04/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
The demographic and environmental influences on large mammal morphology are central questions in ecology. We investigated the effects of population abundance and climate on body size and number of male antler points for the La Poile and Middle Ridge caribou (Rangifer tarandus, L. 1758) herds, Newfoundland, Canada. Across 40 years and 20-fold changes in abundance, adult males and females exhibited diminished stature as indicated by jawbone size (diastema and total mandible length) and the number of antler points at the time of harvest. Associations between jawbone size and population abundance at birth were consistently negative for both herds, both sexes, and all age classes. Large-scale climate patterns, as measured by the North Atlantic Oscillation in the winter prior to birth, were also negatively associated with jawbone size. Declines in male antler size, as measured by the number of antler points, were not well predicted by either abundance or climate, suggesting other factors (e.g., current, rather than latent, foraging conditions) may be involved. We conclude that these morphological changes indicate competition for food resources.