Title
Recolonizing wolves and mesopredator suppression of coyotes: Impacts on pronghorn population dynamics
Author(s)
Berger ,K.M.; Conner, M.M.
Published
2008
Publisher
Ecological Applications
Abstract
Food web theory predicts that the loss of large carnivores may contribute to elevated predation rates and, hence, declining prey populations, through the process of mesopredator release. However, opportunities to test predictions of the mesopredator release hypothesis are rare, and the extent to which changes in predation rates influence prey population dynamics may not be clear due to a lack of demographic information on the prey population of interest. We utilized spatial and seasonal heterogeneity in wolf distribution and abundance to evaluate whether mesopredator release of coyotes (Canis latrans), resulting from the extirpation of wolves (Canis lupus) throughout much of the United States, contributes to high rates of neonatal mortality in ungulates. To test this hypothesis, we contrasted causes of mortality and survival rates of pronghorn (Antilocapra americana) neonates captured at wolf-free and wolf-abundant sites in western Wyoming, USA. between 2002 and 2004. We then used these data to parameterize stochastic population models to heuristically assess the impact of wolves on pronghorn population dynamics due to changes in neonatal survival. Coyote prédation was the primary cause of mortality at all sites, but mortality due to coyotes was 34% lower in areas utilized by wolves (P < 0.001). Based on simulation modeling, the realized population growth rate was 0.92 based on fawn survival in the absence of wolves, and 1.06 at sites utilized by wolves. Thus, wolf restoration is predicted to shift the trajectory of the pronghorn population from a declining to an increasing trend. Our results suggest that reintroductions of large carnivores may influence biodiversity through effects on prey populations mediated by mesopredator suppression. In addition, our approach, which combines empirical data on the population of interest with information from other data sources, demonstrates the utility of using simulation modeling to more fully evaluate ecological theories by moving beyond estimating changes in vital rates to analyses of population-level impacts. © 2008 by the Ecological Society of America.
Keywords
abundance; canid; ecological modeling; food web; mortality; population decline; population dynamics; recolonization; reintroduction; ruminant; spatial distribution; survival; Antilocapra americana; Antilocapridae; Canidae; Canis familiaris; Canis latrans; Canis lupus; Ungulata; biological product; animal; antelope; article; coyote; ecosystem; environmental protection; female; male; physiology; United States; wolf; Animals; Antelopes; Biological Products; Conservation of Natural Resources; Coyotes; Wolves; Wyoming; SURVIVAL ESTIMATION; MATRIX MODELS; MULE DEER; RED DEER; CONSERVATION; EXTINCTION; DEMOGRAPHY; MORTALITY; VIABILITY; SYNCHRONY
Access Full Text
A full-text copy of this article may be available. Please email the WCS Library to request.
![]()
Back
PUB12030