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Dryad

Data for: Spatial prey availability and pulsed reproductive tactics: encounter risk in a canid-ungulate system

Data files

Jan 31, 2024 version files 5.07 MB

Abstract

  1. Predation risk is a function of spatiotemporal overlap between predator and prey, as well as behavioral responses during encounters. Dynamic factors (e.g., group size, prey availability, and animal movement or state) affect risk, but rarely are integrated in risk assessments. Our work targets a system where predation risk is fundamentally linked to temporal patterns in prey abundance and behavior. For neonatal ungulate prey, risk is defined within a short temporal window during which the pulse in parturition, increasing movement capacity with age, and anti-predation tactics have the potential to mediate risk.
  2. In our coyote – mule deer (Canis latransOdocoileus hemionus) system, leveraging GPS data collected from both predator and prey, we tested expectations of the shared enemy and reproductive risk hypotheses. We asked two questions regarding risk: (A) how do primary and alternative prey habitat, predator and prey activity, and reproductive tactics (e.g., birth synchrony, maternal defense) influence vulnerability of a neonate encountering a predator? (B) How do the same factors affect behavior by predators relative to time before and after an encounter?
  3. Despite increased selection for mule deer and intensified search behavior by coyotes during the peak in mule deer parturition, mule deer were afforded protection from predation via predator swamping, experiencing reduced per-capita encounter risk when most neonates were born. Mule deer occupying rabbit habitat (Sylvilagus spp.; coyote’s primary prey) experienced the greatest risk of encounter but the availability of rabbit habitat did not affect predator behavior during encounters. Encounter risk increased in areas with greater availability of mule deer habitat, coyotes shifted their behavior relative to deer habitat, and the pulse in mule deer parturition and movement of neonatal deer during encounters elicited increased speed and tortuosity by coyotes.
  4. In addition to the spatial distribution of prey, temporal patterns in prey availability, and animal behavioral state were fundamental in defining risk. Our work reveals the nuanced consequences of pulsed availability on predation risk for alternative prey, whereby responses by predators to sudden resource availability, the lasting effects of diversionary prey, and inherent antipredation tactics ultimately dictate risk.