Breeding takes place between late January to early March, and gestation is 60-63 days. The pups are kept at a den site for 6 to 8 weeks. By mid June the pups are moved to rendezvous sites where they stay while adult search for food. In September and October, when the pups become large enough to travel with the adults, rendezvous sites are vacated and the pack moves as a single unit throughout its territory. Wydeven et al.
Wolves are susceptible to diseases, predation, human persecution, starvation, and accidents.
Diseases such as canine distemper, canine parvovirus, Lyme disease, and blastomycosis have been observed in Wisconsin wolves. Wydeven et al. Mange has been observed frequently in Wisconsin wolves since 1992, and has been diagnosed as the primary cause of death for at least nine wolves in the past 5-6 years. Miscellaneous items accounted for the remainder. The large land requirements of wolves can conflict with human use of those lands.