Great Basin Naturalist


In this paper we evaluated traffic characteristics and vegetation and topographic features associated with mule deer kills on 3 highways (US 40, SR 32, SR 248) in northeastern Utah. We also compared number, and sex and age composition of roadkills to that of the living population observed during spotlight counts. From 15 October 1991 to 14 October 1993 we documented 397 deer roadkills: 51.6% were does, 18.9% bucks, 21.7% fawns, and 7.8% could not be classified. Sixty-seven percent of adult kills were ≤2.5 yr of age. Kill composition compared closely to spotlight counts. Of 1515 spotlight deer, 65.2% were does, 8.9% bucks, and 25.9% fawns. Spotlight density and deer mortality were strongly correlated from summer 1992 through summer 1993 (r = 0.94).

Traffic conditions, topographic features, and vegetative characteristics contributed to mortality levels. Roadkills were highest along US 40 (68% year 1, 55% year 2) where traffic volume and speed were significantly higher along either state route. Large drainages intersected highways in 78% of designated kill zones. Roads adjacent to agricultural areas along all routes sustained the fewest highway mortalities. Percent cover was higher (40%) in kill zones than in other areas (29%).