Wolves increase germination speed and success of blueberries

Seed dispersal plays a key role in facilitating important ecological processes that reduce plant competition, parasitism and predation while promoting gene flow and biodiversity. In many ecosystems across North America and Eurasia, wolves consume fruits when available. However, the impact of wolf consumption on seeds, particularly germination success and speed, remains unknown. We extracted blueberry seeds from wolf scats and fresh fruits in the Greater Voyageurs Ecosystem, Minnesota, USA, where wolves forage extensively on blueberries in summer. We grew seeds under controlled conditions to assess if blueberry seeds deposited in wolf scat germinate more rapidly and successfully than seeds from berries alone (control). Seeds that passed through wolf digestive tracts had higher germination success and speed than controlled seeds. This pattern suggests blueberries receive positive benefits passing through wolf gastrointestinal systems. This finding, in combination with wolves' propensity to travel long distances in short periods, indicates wolves are likely effective long-distance dispersers of blueberry seeds. Thus, our findings reveal another way wolves are likely connected to larger ecological processes in boreal ecosystems, and possibly other ecosystems where wolves consume fruits.