The wolverine, formally known as Gulo gulo, is the largest terrestrial member of the weasel family, Mustelidae. It is a stocky, powerfully built mammal whose appearance often resembles a small, compact bear. Its anatomy is adapted to harsh, cold northern environments, with physical features contributing to its reputation for hardiness and strength.
Overall Build and Dimensions
The wolverine presents a broad, low-slung body profile supported by short, muscular legs, giving it a powerful appearance. Adult wolverines typically measure between 65 to 105 centimeters in body length, plus a bushy tail that adds another 13 to 26 centimeters. They stand relatively short at the shoulder, with heights generally ranging from 36 to 45 centimeters.
This robust frame contributes to a body weight ranging from approximately 9 to 30 kilograms. A notable difference exists between the sexes, as males are generally larger and heavier than females, sometimes by as much as 30%. The animal’s compact musculature and powerful limbs maximize leverage and strength, enabling movements characteristic of a low-to-the-ground predator.
The Distinctive Coat and Coloration
The wolverine’s coat is highly adapted for insulation in sub-zero climates. It consists of thick underfur beneath long, coarse guard hairs, creating a dense covering resistant to frost and water. The primary color of the coat is typically a dark brown to blackish-brown across the majority of the body.
Contrasting this dark base color is the most recognizable feature: a broad, light-colored band that runs from the shoulders and flanks along the animal’s sides. This stripe, often yellowish, buff, or creamy white, arches upward and sometimes merges over the rump near the base of the tail. The intensity of this lateral striping can vary significantly between individuals.
Head and Facial Features
The wolverine’s head is broad and rounded, appearing somewhat large in proportion to its neck and body. The face is dominated by a dark rostrum and a set of small, dark eyes that give it a focused gaze. Its ears are small and round, often nearly hidden within the thick surrounding fur, which serves as protection against freezing temperatures.
The skull structure is robust, housing powerful jaw muscles that contribute to a formidable bite force. This strength is necessary for utilizing its specialized dentition, which includes massive carnassial teeth. These modified fourth upper premolars and first lower molars are rotated 90 degrees inward, creating a shearing action used to slice through frozen meat and crush bone. This dental arrangement allows the wolverine to process carrion and bone fragments.
Specialized Paws and Claws
The wolverine possesses large, five-toed paws that are disproportionately sized compared to its short legs. This large surface area functions similarly to a snowshoe, distributing the animal’s weight and facilitating efficient travel across deep snow. The wolverine uses a semi-plantigrade form of locomotion, placing weight primarily on the metatarsals of its feet.
Each digit is tipped with a long, curved claw that is considered semi-non-retractable, unlike those of a cat. These sharp, hooked appendages enable the wolverine to secure a firm grip on icy surfaces and snow. The structure of these claws also aids in digging through frozen ground and snowpack, which is necessary for accessing cached food or winter dens.