A review of population and landscape level dynamics associated with pneumonia outbreaks in bighorn sheep with implications for land management

Abstract

Wildlife conservation necessitates understanding spatiotemporal drivers that facilitate disease outbreaks. Wildlife diseases are influenced by population and landscape level factors which affects host species' persistence through time. Recurrent pneumonia outbreaks in bighorn sheep have impeded population recovery throughout the western US. Recovery efforts have included translocating animals, limiting contact with known reservoirs, removing infected individuals, and depopulating herds, but pneumonia outbreaks continue to negatively impact recovery. Here, our objective was to systematically review the current literature focused on population and landscape level drivers that can contribute to pneumonia outbreaks in bighorn sheep.We reviewed 115 studies and discovered consistent themes important to address for future conservation. One of the primary themes to advance management includes understanding how population demographics, such as age and sex cohorts, can help elucidate drivers and maintenance of pathogens associated with respiratory disease. Second, broadening knowledge of landscape level processes including population connectivity and metapopulation dynamics can inform management and recovery efforts. We identified a need for comprehensive assessments that incorporate population dynamics, landscape genomics, and population connectivity across multiple spatiotemporal scales to advance landscape management. Finally, we provide directions for future research to help managers mitigate pneumonia outbreaks and aid bighorn sheep recovery.