Exploring management options for moose at their southern range limits considering growing disease risk

Abstract

1. Populations of cold-adapted species are increasingly vulnerable along their low-latitude range limits due to shifting environmental conditions, biotic interactions, and anthropogenic pressures. Managing these populations is particularly challenging because of complex ecological dynamics, conflicting stakeholder interests, and decision-making under uncertainty. 2. We explored population growth (λ) of moose ( Alces alces ) under different hypothetical management scenarios, simulating combinations of five hypothetical harvest levels with three levels of disease impact. 3. Facing current disease, the population could support multiple levels of conservative harvest. Under elevated levels of disease-caused mortality, projections indicated declines for all harvest scenarios. We projected increases across all harvest scenarios when overlap with white-tailed deer ( Odocoileus virginianus ) was hypothetically reduced and disease mortality in moose minimized. We investigated whether uncertainty in moose demographic parameters altered population trajectory, and found changes in adult fecundity and calf survival could alter harvest decisions when λ<1. 4. Practical implication . While moose population trajectories may remain stable under current conditions, management of white-tailed deer that reduces moose exposure to lethal parasites may provide the greatest utility in sustaining moose in New York given the potential for increased disease. Continued monitoring of population size, growth, and disease prevalence would inform sustainable moose harvest levels that balance social and ecological management considerations.