INVESTIGATION OF THE HABITAT AND CLIMATE DRIVERS OF COLLARED PIKA DISTRIBUTION AND VULNERABILITY

Abstract

As environmental conditions continue to change at a rapid rate, understanding habitat requirements and climate vulnerabilities is critical for species conservation. The collared pika (Ochotona collaris), an alpine specialist found in Alaska and northern Canada, faces potential threats from climate change, yet its habitat requirements and responses to environmental change remain poorly understood. In this study, we use existing spatial data, combined with observations from new survey efforts, to 1) identify regional variation in collared pika habitat preferences and climate response, and 2) assess the climate change vulnerability of collared pikas and predict changes in distribution linked to future climate scenarios. To identify habitat preferences, we used a model selection approach, comparing climate and habitat characteristics at known collared pika occurrences to those at surrounding areas. Our analysis indicated that collared pika occurrence is primarily driven by the presence of talus, proximity to the talus edge (with pikas preferring areas closer to vegetation), and talus patch size (with pikas preferring small patches). The rangewide model indicated that collared pika occurrence was positively correlated with maximum winter temperature and negatively correlated with maximum summer temperature, annual precipitation, and solar radiation. While preferences for talus characteristics remained consistent rangewide, the effect of climate variables including precipitation and maximum summer temperature varied regionally. To assess climate vulnerability, we combined trait-based and correlative modeling approaches, with the results suggesting the species has high vulnerability to climate change. Our trait-based assessment indicated that collared pikas are moderately susceptible to climate change due to high exposure to changing conditions, high sensitivity to climatic variables, and low adaptive capacity. To predict future changes in distribution, we employed a presence-background species distribution modeling technique to identify the current climatic niche and projected this model into future climate scenarios. Our models suggest a loss of ~55-70% of climatically suitable areas by 2080. Together, these results inform conservation status and strategies for this species and highlight the importance of conducting regional and species-specific analyses.