Sampling a pika's pantry: Temporal shifts in nutritional quality and winter preservation of American pika food caches

Climate change is increasing temperature, decreasing precipitation, and atmospheric CO2 concentrations in many ecosystems. As carbon rises, plants may increase carbon-based defenses, such as phenolics, thereby potentially affecting food quality, foraging habits, habitat suitability for mammalian herbivores. In alpine habitats, the American pika (Ochotona princeps) a model species studying effects of changing plant chemistry on mammals. To survive between growing seasons, pikas cache “haypiles” rich phenolics. Although they are toxic to pikas, phenolic compounds facilitate retention biomass nutrition during storage, degrade over time. Alpine avens (Geum rossii, Rosales: Rosaceae) high-phenolic that comprises up 75% haypiles Colorado. Here, we tested hypothesis contemporary climate has affected nutritional value last 30 years. Specifically, compared activity, overwinter preservation collected at Niwot Ridge, Colorado (USA), 1992 those 2010 2018, spanning nearly three decades change. Phenolic activity increased since 1992, while fiber nitrogen content decreased. Importantly, also increased, particularly windblown slopes without long-lasting snow cover. Previous studies indicate this site still depend their winter caches. Higher could therefore enhance winter; however, if must further delay consuming these avoid toxicity or invest extra energy detoxification, then gains from enhanced not be beneficial. This study provides important insights into how climate-driven changes will affect herbivores future.