Forest Sciences Commons^™

Disease Introduction Is Associated With A Phase Transition In Bighorn Sheep Demographics, Kezia R. Manlove, E. Frances Cassirer, Paul C. Cross, Raina K. Plowright, Peter J. Hudson

Wildland Resources Faculty Publications

Ecological theory suggests that pathogens are capable of regulating or limiting host population dynamics, and this relationship has been empirically established in several settings. However, although studies of childhood diseases were integral to the development of disease ecology, few studies show population limitation by a disease affecting juveniles. Here, we present empirical evidence that disease in lambs constrains population growth in bighorn sheep (Ovis canadensis) based on 45 years of population‐level and 18 years of individual‐level monitoring across 12 populations. While populations generally increased (λ = 1.11) prior to disease introduction, most of these same populations experienced an abrupt change …