Potential Effects of Oil and Natural Gas Development on Mule Deer (Odocoileus hemionus) Survival and Fawn Rearing Resource Selection

Abstract

A worldwide increasing demand for both renewable and non-renewable energy resources has been ongoing for the past 50 years and is projected to continually increase for the next two decades. The direct and indirect effects of oil and natural gas development are not quantified but may be playing an important role in mule deer population dynamics. For this project I: (1) evaluated the potential effects of oil and natural gas development on survival probabilities of mule deer and; (2) evaluated the potential effects of oil and natural gas development on fawn rearing resource selection. I assessed mule deer survival and rearing resource selection by evaluating 268 global positioning system (GPS) radio-collars that were deployed from 2012 to 2016. Survival probability was evaluated using known-fate models. Survival covariates included proximity to oil and natural gas development, density of actively drilling wells, road density, minimum temperature, normalized difference vegetation index (NDVI), and age. Rearing resource selection was evaluated using discrete choice analysis. The rearing resource covariates included distance to oil and natural gas development, distance to road, elevation, terrain ruggedness, slope, distance to water resources, and forage availability. I found that distance to nearest active drilling rig had a weak negative effect on mule deer survival probability. I also found that mule deer rearing resource selection was moderately related to distance from an active drilling rig. Determining the potential effects that oil and natural development have on mule deer survival and rearing resource selection can help inform managers on ways to mitigate potential adverse effects.

Mule deer mortality in the northern Great Plains in a landscape altered by oil and natural gas extraction

“…Although few investigations have examined the effect of energy development on juvenile and adult mule deer mortality, these results are consistent with research showing no effect of distance to oil and gas wells on pronghorn summer mortality risk (Reinking et al 2018) or mule deer fawn mortality (Peterson et al 2018). A possible reason we failed to detect a relationship between distance to oil and gas development and mortality risk is because mule deer locations were rarely in proximity to these areas (Kolar et al 2017, Skelly 2018; Figure 6). Mule deer avoidance of all types of oil and gas development (i.e., active drilling rigs and well pads) has been previously documented in Wyoming and Colorado, USA (Northrup et al 2015, Sawyer et al 2006, 2009, 2017).…”

“…There was no support for our original prediction of greater mortality risk in proximity to primary and secondary roads. Although mule deer have been demonstrated to avoid areas close to roads (Sawyer et al 2009, Northrup et al 2015, Skelly 2018), the effects of proximity to roads on mortality risk is unknown. Hunting can be the main source of mortality in adult mule deer (83% [Wood et al 1989], 22.6% [Carnes 2009]), and hunter success increases with increased road density (Dorning et al 2016).…”