Does human predation risk affect harvest susceptibility of white-tailed deer during hunting season?

Abstract

Large carnivores are considered a primary source of mortality for many ungulate populations, but harvest by hunters is the primary means of population management. However, research is needed to evaluate how human predation risk influences observability (a surrogate to harvest susceptibility) of ungulates. We determined how hunting intensity and duration influence observation rates of white-tailed deer (Odocoileus virginianus) and how deer behavior (i.e., movement rate and resource selection) affects observation rates. We sampled 37 adult (!2 yr) male deer at 2 levels of risk (i.e., low-risk ¼ 1 hunter/101 ha; and high-risk ¼ 1 hunter/30 ha) during 3 exposure periods (i.e., first, second, and third weekend of hunting) on a 1,861-ha property in Oklahoma, USA, during the 2008 and 2009 rifle deer-seasons. Observation rates (collared deer/hunter-hr/day) were greatest during the first weekend in both the low-and high-risk treatments, but declined each weekend thereafter in both treatments. Immediately prior to hunter observation, movement rate of observed collared deer was greater than that of unobserved collared deer, but only when hunting risk was high. Greater movement rates of deer in the high-risk treatment also led to a greater probability of observation. Hunters also had a greater probability of observing collared deer at higher elevations. Overall, deer modified their behavior to avoid detection by hunters. These results can be used to explain decreased observation rates to hunters and to modify harvest rates by altering timing and intensity of human predation risk during the recreational hunting season to help achieve population management goals through harvest. Ó 2014 The Wildlife Society.

Impacts of human hunting on spatial behavior of white-tailed deer (Odocoileus virginianus)

“…Therefore, we predicted that deer would reduce movements to avoid detection by hunters during the hunting season (Little et al 2014); this prediction was supported by these findings in that total distance travelled over 2 days declined at the greatest rate during the hunting season. Most often, flight responses do not last over long periods of time (Frid and Dill 2002).…”

“…Treatment areas were re-randomized during year 2. The two hunted treatments were further divided into hunting compartments to distribute hunters across the landscape at the appropriate density of hunters (Little et al 2014(Little et al , 2016. Although the targeted density of hunters was not met each day of the 16-day hunting season, we did, however, maintain the respective ratio of hunters between high-and low-density treatments.…”

“…Athough this study does not investigate changes in habitat type (e.g., from using more open to more wooded areas during hunt), deer have been found to alter their movements in favor of more concealed areas to avoid hunting activities (Kamei et al 2010;Little et al 2014).…”

“…Risk effects are realized when prey must alter their behavior in response to predators (Nelson and Mech 1991;Creel and Christianson 2008). For example, it has been found that male white-tailed deer (Odocoileus virginianus (Zimmermann, 1780)) can avoid detection from hunters by changing resource selection and movement patterns (Little et al 2014). Similarly, western roe deer (Capreolus capreolus (L., 1758)) avoid hunters by using less risky habitats (Padié et al 2015).…”

Unpaved roads are not adequate surrogates of true transects for sampling agoutis

“…In the dry season, agoutis were observed resting less when sampled from roads, while in the wet season, they feed/forage more in roads when compared to transects. Everything else being equal, observers can detect animals more easily when they are active (Little et al 2014) rather than when they are inactive (resting, sleeping, etc. ) and this is not different for agoutis.…”