Effects of seasonal weather on breeding phenology and reproductive success of Alpine Ptarmigan in Colorado

Animal populations occurring at high elevations are often assumed to be in peril of extinctions or local extirpations due to elevational-dispersal limitations and thermoregulatory constraints as habitats change and warm. However, long-term monitoring of high-elevation populations is uncommon relative to those occurring at lower elevations, and evidence supporting this assumption is limited. We analyzed 45 years of reproductive data for two Colorado populations of white-tailed ptarmigan (Lagopus leucura), an alpine-endemic species with restricted distribution in western North America.

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