Predatory senescence in ageing wolves

Authors

Daniel R. MacNulty, Utah State UniversityFollow
Douglas W. Smith, Yellowstone National ParkFollow
John A. Vucetich, Michigan Technological UniversityFollow
L. David Mech, USGS Northern Prairie Wildlife Research CenterFollow
Craig Packer, University of MinnesotaFollow

Date of this Version

2009

Citation

Ecology Letters, (2009) 12: 1347–1356

doi: 10.1111/j.1461-0248.2009.01385.x

Comments

US govt work.

Abstract

It is well established that ageing handicaps the ability of prey to escape predators, yet surprisingly little is known about how ageing affects the ability of predators to catch prey. Research into long-lived predators has assumed that adults have uniform impacts on prey regardless of age. Here we use longitudinal data from repeated observations of individually-known wolves (Canis lupus) hunting elk (Cervus elaphus) in Yellowstone National Park to demonstrate that adult predatory performance declines with age and that an increasing ratio of senescent individuals in the wolf population depresses the rate of prey offtake. Because this ratio fluctuates independently of population size, predatory senescence may cause wolf populations of equal size but different age structure to have different impacts on prey populations. These findings suggest that predatory senescence is an important, though overlooked, factor affecting predator-prey dynamics.

Supplemental table S! (15 pp.) attached below.