<P> Successful males will form lifetime relationships with two or three females, which they will visit occasionally, while other males are left without a mate . Mating season is in the summer, but the actual implantation of the embryo (blastocyst) in the uterus is stayed until early winter, delaying the development of the fetus . Females will often not produce young if food is scarce . The gestation period is 30--50 days, and litters of typically two or three young ("kits") are born in the spring . Kits develop rapidly, reaching adult size within the first year . The typical longevity of a wolverine in captivity is around 15 to 17 years, but in the wild the average lifespan is more likely between 8 and 10 years . Fathers make visits to their offspring until they are weaned at 10 weeks of age; also, once the young are about six months old, some reconnect with their fathers and travel together for a time . </P> <P> Wolverines live primarily in isolated arctic, boreal, and alpine regions of northern Canada, Alaska, Siberia, and Fennoscandia; they are also native to European Russia, the Baltic countries, the Russian Far East, northeast China and Mongolia . In 2008 and 2009, wolverines were sighted as far south as the Sierra Nevada, near Lake Tahoe, for the first time since 1922 . According to a U.S. Fish and Wildlife Service publication, as of 2014 "wolverines are found in the North Cascades in Washington and the Northern Rocky Mountains in Idaho, Montana, Oregon (Wallowa Range), and Wyoming . Individual wolverines have also moved into historic range in the Sierra Nevada Mountains of California and the Southern Rocky Mountains of Colorado, but have not established breeding populations in these areas ." </P> <P> In 2004, the first confirmed sighting of a wolverine in Michigan since the early 19th century took place, when a Michigan Department of Natural Resources wildlife biologist photographed a wolverine in Ubly, Michigan . The specimen was found dead at the Minden City State Game Area in Sanilac County, Michigan in 2010; no further wolverines have been spotted in Michigan . </P> <P> However, most New World wolverines live in Canada and Alaska . </P>

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