The striped skunk, Mephitis mephitis, is the most common species of skunk. Determining the sex of a skunk is challenging because sexual dimorphism is minimal; a female skunk is almost indistinguishable from a male by casual observation. Most visual traits are shared across both sexes, meaning a layperson cannot reliably determine the sex of an individual skunk in the wild. Differences are primarily related to overall size and subtle anatomical features that require close inspection.
Shared Visual Characteristics of Skunks
The female skunk shares the iconic, universally recognizable coat pattern, which serves as a warning signal to potential predators. The pelage is predominantly deep black, broken by a narrow white line running from the nose up the forehead. This white marking widens into a patch on the back of the head and then divides into a prominent V-shape over the shoulders. These two thick white stripes continue down the back toward the bushy tail.
The animal has a stout, compact body supported by short legs, giving it a characteristic low-to-the-ground posture. Its head is small and conical, tapering to a pointed snout with small, black eyes and short, rounded ears. The forefeet are equipped with long, curved claws that are adapted for digging and foraging for insects and grubs. The long, bushy tail, often tipped with white hairs, contributes to the skunk’s total length, which ranges from 465 to 815 millimeters (about 18 to 32 inches).
Subtle Differences in Size and Build
While the coat pattern is the same, subtle differences in size and build are the most significant visual cues that distinguish the female skunk. Females are generally smaller and less robust than their male counterparts. On average, the male striped skunk is approximately 10 to 15 percent larger than the female. This difference is often too slight to be reliably judged in the field.
The overall body mass for a striped skunk can fluctuate dramatically throughout the year, ranging from approximately 0.7 to 6.3 kilograms (about 1.5 to 13.9 pounds). Females typically fall on the lower end of this range, often weighing between 2.7 and 4.5 kilograms (6 to 10 pounds). Weight is influenced by the season, as skunks can lose up to 50 percent of their body weight during the winter months, relying on fat reserves. A large, well-fed female might easily outweigh a smaller, less robust male, complicating visual identification based solely on size.
Anatomical Confirmation of Sex
A definitive identification of a female skunk requires a close look at the external reproductive anatomy. In all skunks, the external genitalia are located close to the anus, but the distance between the urogenital opening and the anus differs between the sexes. The female’s vulva is situated immediately next to the anal opening. Conversely, the male’s penile sheath is positioned further away from the anus.
Female skunks also possess small teats, or mammary glands, which are generally not noticeable unless the female is nursing her young. During this period, these mammary glands may become visibly swollen, offering a temporary, but clear, indication of her sex.