Modified jump-outs for white-tailed deer and mule deer

Abstract

The height of the jump-outs should be low enough for the target species to readily jump down to the safe side, or the habitat side, of the fence. At the same time, the jump-outs should be high enough to discourage animals that are on the habitat side of the fence from jumping up into the fenced road corridor. Previous research along US Hwy 93 North in Montana showed that only about 32% of the mule deer and about 7% of the white-tailed deer that appeared on top of the jump-outs, jumped down to safety. For this project, 10 of the jump-outs along US Hwy 93 North were lowered in height and provided with a bar on top. The height of the bars (made from rebar) and their setback from the vertical face of the jump-outs was adjustable and the researchers applied 4 different treatments: 2 different heights (18 and 15 inches) and 3 different setbacks (4, 12, and 15 inches). The overall effectiveness of the lowered jump-outs in allowing white-tailed deer to jump down, regardless of the height and setback of the bar, was only just above 5% (no improvement). For mule deer the effectiveness of the lowered jump-outs in allowing them to jump down, regardless of the height and setback of the bar, was about 64% (this was double the effectiveness of non-modified jump-outs).