Can coyote predation risk induce reproduction suppression in white‐tailed deer?

Abstract

Abstract. Predators can have powerful nonconsumptive effects on their prey by inducing behavioral, physiological, and morphological responses. These nonconsumptive effects may influence prey demography if they decrease birthrates or increase susceptibility to other sources of mortality. The Reproductive Suppression Model suggests that iteroparous species may maximize their lifetime reproductive success by suppressing their reproduction until a future time, when conditions may be more favorable. Coyote (Canis latrans) range expansion in the United States has exposed white-tailed deer (Odocoileus virginianus) populations to increased predation risk, and coyote predation can have profound effects on white-tailed deer reproductive success. We evaluated effects of temporal variation in predation risk (i.e., coyote-deer ratios) on fecundity and reproductive success of white-tailed deer on the Joseph W. Jones Ecological Research Center in southwestern Georgia, United States, by exploiting a rapid decline in coyote abundance to establish a natural experiment. We measured fecundity by examining ovaries for evidence of ovulation, and measured reproductive success using evidence of lactation from deer harvested before and after the decline in coyote abundance. We found that incidence of ovulation and lactation increased following the decline in predation risk. Our results suggest coyotes may be able to influence deer recruitment, independent of direct predation, through interactions that result in reduced fecundity. More broadly, our study suggests that in order to understand the totality of the effect of predators on prey population dynamics, studies should incorporate measures of direct and indirect predator effects.

Initial colonization of Long Island, New York by the eastern coyote, Canis latrans (Carnivora, Canidae), including first record of breeding

“…In this case, we received numerous-albeit unconfirmed-reports that this pair of coyotes had lived and bred for several years in the original 7.64 ha woodlot and, we speculate, only became visible to officials and the larger community once their territory was developed and they were forced to move their 8 young pups out of the woodlot. Also, coyotes are one of the few predators that can thrive in developed environments and thus may fill a valuable ecological role (Rogers and Caro 1998, Henke and Bryant 1999, Crooks and Soule 1999, Cherry et al 2016). Managers and officials should thus implement management policies that focus on coexistence, public education, aversive conditioning, and conservation ethics rather than broad-scale lethal removal, although targeted lethal removal needs to remain an option for genuine problem animals.…”

Fear of humans as apex predators has landscape‐scale impacts from mountain lions to mice

“…Moreover, if fear of humans triggers substantial sublethal effects comparable to those fear itself has been demonstrated to cause in other predator–prey systems [e.g. increased physiological stress (Zanette et al ), reduced reproductive success (Zanette et al ; Cherry et al )], this may translate to additional widespread but largely unmeasured impacts of humans on wildlife populations. Given the potential for sublethal effects, apparently ‘human‐tolerant’ species (e.g.…”

Fire‐mediated foraging tradeoffs in white‐tailed deer

“…) and examination of reproductive tracts for evidence of ovulation from harvested adult female white‐tailed deer (Cherry et al. ). We used animal locations from June to August to calculate a 95% MCP for each white‐tailed deer to represent a generalized fawn‐rearing seasonal area of use.…”

“…Capture and chemical immobilization have the potential to negatively affect maternal investment in ungulates (Côt e et al 1998), and specifically, xylazine hydrochloride can induce anorexia in white-tailed deer (Warren et al 1984), which could impair lactation and induce abandonment. We sought to minimize these potential effects by halting capture six weeks before estimated peak fawning (Cherry et al 2016) and not targeting females that appeared parturient. We fit adult female deer with Global Positioning System Collars (ATS 2110 D; Advanced Telemetry Systems, Isanti, Minnesota, USA).…”