Effects of removal on a lightly exploited coyote population in eastern Nevada

Coyote (Canis latrans) removal is a common, yet controversial, management practice to increase game populations throughout the West. I studied the effect of removal on coyote populations in eastern Nevada from 2004 to 2008 and reviewed 27 available publications to determine the level of human exploitation on my study populations. Removals were performed by USDA Wildlife Services (WS) to benefit game populations and involved the use of trapping, neck snaring, and ground and aerial shooting. To determine if the removal had an effect on the coyote populations, I measured 3 parameters: the presence or absence of skewed sex ratios; proportions of juveniles in the population; and average adult age. Sex was determined at the time of ground removal efforts. Canine teeth were acquired from 96% of coyotes removed from the ground; cementum annuli analysis was performed for aging. Due to WS removal efforts prior to 2004, coyote populations likely were in a lightly exploited state when the study began. Where removal efforts were the highest (65% of total), there was a resulting decline in the mean age of coyotes, an increase in percentage of juveniles in the population, and a skewed sex ratio, indicating that this population may be heavily exploited. No change in these parameters occurred in areas where 35% of the total removals occurred. This information should help wildlife managers understand the exploitation levels of their own coyote populations.