Cattle ranchers in southwestern Alberta have suspected it for a long time and now, GPS tracking equipment confirms it: wolf packs in the area are making cow meat a substantial part of their diets. University of Alberta researchers tracked wolves to bone yards, where ranchers dispose of dead cattle, and to sites of fresh cow kills. The study was done over two grazing seasons in 2008 and 2009. The vast study area in southwestern Alberta includes private ranchland and wooded public lands bordering the Rocky Mountains. Researchers found that during the summer months when livestock was set out to graze on public lands, cattle made up to 45 per cent of the diet for the three wolf packs in the study. This shows a seasonal switch from the wolf’s usual pattern of wild prey in the non-grazing season to cattle in the grazing season.