Hunting techniques and tool use by north American badgers preying on Richardson's ground squirrels

Techniques used by North American badgers (Taxidea taxus) when hunting Richardson's ground squirrels (Spermophilus richardsonii) were assessed over a 15-year period in southern Alberta to determine the relationship between activity of prey and methods used to capture prey. Badgers frequently hunted hibernating squirrels in autumn, sometimes hunted infants in spring, and rarely hunted active squirrels in summer. Badgers always captured hibernating squirrels and infants underground, usually captured active squirrels underground, and sometimes intercepted fleeing squirrels aboveground. Regardless of season or year, the most common hunting technique used by badgers was excavation of burrow systems, but plugging of openings into ground-squirrel tunnels accounted for 5-23% of hunting actions in 4 consecutive years. Plugging occurred predominantly in mid-June to late July before most ground squirrels hibernated and in late August to late October when juvenile males were active but other squirrels were in hibernation. Badgers usually used soil from around the tunnel opening or soil dragged 30-270 cm from a nearby mound (72% and 22% of 391 plugged tunnels, respectively) to plug tunnels. The least common (6%), but most novel, form of plugging used by I badger involved movement of 37 objects from distances of 20-105 cm to plug openings into 23 ground-squirrel tunnels on 14 nights. Aimed movement of objects to plug openings into burrow systems occupied by ground squirrels qualified this badger as a tool user.