Gulo gulo

Wolverines are usually solitary, territorial animals that remain active throughout the year and travel enormous distances across large home ranges. They are opportunistic carnivores and scavengers, feeding on carrion, small mammals, birds, eggs, and occasionally vegetation, while using scent markings and vocalizations to communicate.

Mating generally occurs from late spring through summer, but delayed implantation postpones embryo development until winter. Females usually give birth to two or three kits in deep snow dens, although litters may range from one to six, and reproduction may be skipped when food conditions are poor.

Wolverines have powerful, bear-like bodies, broad heads, short rounded ears, strong jaws, curved claws, and large feet that help them travel across deep snow. Their thick dark-brown coats commonly feature pale facial markings and lighter stripes extending along the sides toward the bushy tail.

Carl Linnaeus scientifically described the species in 1758 under the original name Mustela gulo, based on specimens associated with Lapland. Hunting, trapping, predator-control programs, and habitat disturbance later eliminated or greatly reduced wolverines across parts of their historical range, particularly in the contiguous United States.

The wolverine is globally classified as Least Concern, but populations occur at naturally low densities and are vulnerable to habitat fragmentation, overharvesting, declining snow cover, and climate-related changes. The distinct North American population in the contiguous United States has been federally listed as Threatened under the Endangered Species Act since January 2024.