A review of vital rates and cause-specific mortality of elk Cervus elaphus populations in eastern North America

A review of elk vital rates in eastern North America is warranted given continued interest in restoring the species to the region and the variation in habitat conditions, anthropogenic influence on population dynamics and predator fauna between eastern and western North America. We reviewed 23 studies of elk demographics from populations in eastern North America and summarized adult (>2 years old), subadult (1-2 years old) and juvenile (0-1 years old) annual survival and fecundity. We also reviewed and compared studies in which causes of mortality in eastern and western North American elk populations were reported. Annual survival of adult and subadult elk in populations in eastern North America was similar to those reported for western North American elk populations. Annual juvenile survival [Ŝ=0.76, standard error (SE)=0.07] in eastern North American elk populations was 53% higher than that in western North American populations. Fecundity rates in elk populations in eastern North America were low (0.75 juveniles per female per year, SE=0.06) compared with fecundity rates typical of western North American populations. Juvenile survival and adult fecundity were lower in recently restored populations (Ŝ=0.65, SE=0.09; 0.62 juveniles per female per year) than in established populations (Ŝ=0.83, SE=0.07; 0.80 juveniles per female per year) in eastern North America. Brainworm Parelaphostrongylus tenuis infection, vehicle collisions and nuisance culling were important factors contributing to mortality in eastern North American, but not in western North American, elk populations. Eastern North American elk populations have the potential to exhibit high population growth rates (λ=1.02-1.29). Variation in vital rates between recently restored and established elk populations highlights the need for continued long-term monitoring of translocated elk populations.