Coyote Predation Effects on White-Tailed Deer Fawns

Abstract

Coyotes (Canis latrans) are a relatively new predator to the southeastern United States, and may be negatively impacting white-tailed deer (Odocoileus virginianus; hereafter, deer) populations. Our objectives were to evaluate the impacts of coyotes on deer fawns by assessing deer fawn survival and cause-specific mortality, and gain an understanding of factors affecting fawn survival and coyote predation. We captured and radio collared 30 fawns in the Red Hills region of Florida and Georgia, USA (2012)(2013). Fawns were monitored for 12 weeks for survival and cause-specific mortality, and we quantified habitat and environmental characteristics of birth sites. Predation (n = 19; 95%) was the leading cause of fawn mortality (n = 20; 67%), with coyote predation (n = 14; 74%) being the most important type of predation. Survival rates for all fawns were greater (P = 0.048) where coyotes were removed compared to nonremoval sites, with 50% and 25% of fawns surviving to 12 weeks on coyote-removal and non-removal sites, respectively. Survival rates of fawns ultimately predated by coyotes were greater (P = 0.096) on coyote-removal than non-removal sites, with 40% and 50% of fawns predated by coyotes within 12 weeks on coyote-removal and non-removal sites, respectively. Survival of all fawns and those predated by coyotes was lower when fawns were born at sites with greater hardwood basal area, total basal area, and canopy closure; and survival improved if born in or near hardwood, natural pine, and managed (planted) pine cover types. Increased canopy cover within 10 m of the birth site was selected by adult females for birth sites of all fawns and those that were predated by coyotes. Compared with fawns that lived, all dying fawns and those predated by coyotes had less shrub cover within 5 m and less grass cover at and within 10 m of the birth site. Coyote removal increased fawn daily survival rates, and habitat played a role in fawn survival.

Factors Determining Coyote (<i>Canis latrans</i>) Diets

“…The relative amount of deer consumed by coyotes in Florida was less than in other studies (e.g., [13] [50]). Our data partly support this conclusion, finding deer use to be greater in the deer fawning season compared with outside of both the deer hunting and fawning seasons, as fawns may be easy prey for coyotes [7]. However, deer fawns were generally, infrequently consumed in Florida, which is similar to that of Swingen et al (2015).…”

“…Coyotes may be taking advantage of these easily obtained food sources by scavenging the remains of hogs used as bait, hogs and deer left in the field, and opportunistically depredating livestock calves and weak or wounded deer and hogs [33]. The greater use of deer by coyotes during the hunting season (26 % occurrence) than other seasons supports this conclusion [11].…”

“…Although studies have documented the potential for coyote food use to negatively affect wildlife and domesticated animals, they are often equivocal, possibly because most are of small spatial extent, which can mask broader habitat and ecosystem effects [11]. In addition, beyond a limited knowledge of the influence of season and animal sex and age, we lack an understanding of determinants of coyote food use [11].…”

“…In addition, beyond a limited knowledge of the influence of season and animal sex and age, we lack an understanding of determinants of coyote food use [11]. A better understanding of these determinants is needed to tailor management strategies and mitigate the negative effects of coyotes.…”

“…Increasing numbers of coyotes in areas such as the southeastern United States [2] [3] are a concern as they may feed on a variety of food items, including important game species, livestock, and pets [4] [5]. Coyotes have been implicated in the decline of numerous wildlife species, negatively affecting them through competition for resources (e.g., bobcats [Lynx rufus]; [6]), predation (e.g., white-tailed deer [Odocoileus virginianus; hereafter, deer]; [7]), and changes in community structure [8] [9] [10].…”