Proportion of calves and adult muskoxen, Ovibos moschatus killed by gray wolves, Canis lupus, in July on Ellesmere Island

Generally Gray Wolves (Canis lupus L., 1758) tend to focus predation on young-of-the-year ungulates during summer, and I hypothesized that wolves preying on Muskoxen (Ovibos moschatus Zimmerman, 1780) in summer would follow that trend. Over 23 July periods observing wolves on Ellesmere Island, Nunavut, Canada, I found that packs of 2-12 adult wolves killed seven calves, one yearling, and five adult muskoxen at distances of 2.9 to 32 km from their current dens and pups. Given a possible bias against finding calves because of their fewer remains, these results do not necessarily refute the hypothesis, but they do make it clear that adult muskoxen form an important part of the wolves' diet in July and thus possibly at other times during summer.