Why do gray wolf packs move pups from dens to rendezvous sites?

Gray wolf packs move their pups from the initial den to an aboveground rendezvous site after a few weeks to provide a location where the young can play and sleep while the adults are away hunting.1

As the pups grow throughout the summer, they are moved more frequently and over greater distances to accommodate their development. By autumn, the pack resumes traveling throughout its territory, and the pups must be capable of keeping up with the group. This transition is part of the pack's highly social structure, where all members participate in the care of the young.12