Changes in vigilance, grazing behaviour and spatial distribution of bighorn sheep due to cattle presence in Sheep River Provincial Park, Alberta

The physical presence of livestock can influence the behaviour of native ungulates. Behavioural data on bite rates and vigilance of Rocky Mountain bighorn sheep were collected during the summer and fall of 2006 in Sheep River Provincial Park, Alberta. Spatial distributions of bighorn sheep and domestic cattle were recorded using daily censuses and GPS collar locations during the same time period. We hypothesized that the presence of cattle would induce a negative behavioural response in bighorn sheep and cause avoidance behaviour. As predicted, foraging bite rates decreased and vigilance rates increased when cattle were located nearby. Vigilance in females was higher than in males. The average distances between bighorn sheep and cows were found to be smaller than expected at random, and minimal distances were not affected by the presence of cows. The sheep were found in the same general areas used by cattle. The cattle presence was shown to influence distribution and behaviour of bighorn sheep, although not in the way we expected.