At least part of this range is a territory, within which individuals of the same sex are not tolerated. A study area of 1,300 sq km there contained a minimum population of 20 wolverines. There was extensive overlap between the ranges of both the same and the opposite sexes, and no territorial defense was observed. There was extensive marking, but such was considered not to define a territory but rather to identify the area being utilized at a given time. The wolverine is solitary except during the breeding season.
Females are monestrous and apparently give birth about every two years.
Mating usually occurs from late April to July, but implantation of the fertilized eggs in the uterus is delayed until the following November to March, and births occur from January to April. The usual number of young per litter is two to four, and the range is one to five. Active gestation lasts 30-40 days. The pelt of the wolverine is not used widely in commerce but is valued for parkas by persons living in the Arctic, because it accumulates less frost than other kinds of fur. Fur trapping has contributed to a decline in the numbers and distribution of the wolverine, but a more important factor may be human consideration of the genus as a nuisance.