Mustela eversmanii
steppe polecat

Steppe polecats are found throughout central and western Europe and throughout most of central Asia (southern Russia, northern Georgia, Kazakhstan, Turkmenistan, Uzbekistan, Tajikistan, Kyrgyzstan, Mongolia, and northern and western China; Wozencraft, 2005). (Wozencraft, 2005)

Steppe polecats inhabit a variety of moderately dry habitats, including steppes, semi-deserts, pastures, and cultivated fields. They tend to avoid forested habitats (Mitchell-Jones et al., 1999; Smith and Xie, 2008). They are commonly found in the plains throughout Russia, Romania, Hungary, Czech Republic, Slovakia, Bosnia, Herzegovina, Croatia, Kosovo, Macedonia, Montenegro, Serbia, and eastern China (Mead et al., 1990). They have been found at elevations of 800 m in Europe and 2,600 m in central Asia. Steppe polecats shelter in burrows, hollow trees, dense vegetation, rock crevices, or abandoned buildings during the day, and some have been known to take shelter in the burrows of their prey (Nowak, 1999). (Mead, et al., 1990; Mitchell-Jones, et al., 1999; Nowak, 2005; Smith and Xie, 2008)

Steppe polecats have long slender bodies, similar to other species in the Mustela genus, and exhibit a variety of color patterns. Generally, the body is straw yellow or pale brown. They have dark dorsal pelage that becomes progressively lighter toward the ventral pelage. The thorax, limbs, inguinal region, and about a third of the tail are dark brown to black, and coloration on the muzzle resembles a mask. As a result, they are sometimes referred to as the "masked polecat" (Nowak, 1999). They weigh between 1350 and 2050 g and are between 290 and 562 mm in length. (Nowak, 1999)

Steppe polecats are polygynous, with males having more than one mate during breeding season (Webster, 2010). (Webster, 2010)

Steppe polecats breed seasonally, between February and March. If a female loses her litter (predation, illness, etc.), she may attempt to produce another litter later in the year. Gestation last for 38 to 41 days, and parturition occurs during March and April. Average litter size is 8 to 10 pups, which weigh approximately 4 to 6 g at birth. Pups begin to open their eyes at 1 month old and are weaned and begin hunting with their mother at 1.5 months old. Young disperse at 3 months old and reach sexually maturity at approximately 9 months old (Nowak, 2005). (Nowak, 2005)

Steppe polecats nurse for about 1 month after birth. After weaning, pups can open their eyes and begin hunting with their mother. By 3 months old, pups are independent and leave there mothers (Nowak, 2005). Little information exists on paternal investment in steppe polecats. (Nowak, 2005)

The lifespan of steppe polecats has not been documented. Ferrets (Mustela putorius), a close relative of steppe polecats, live from 4 to 5 years in the wild and 8 to 10 years in captivity (Nowak, 1999). (Nowak, 1999)

Steppe polecats live in breeding colonies, which consist of multiple mated pairs and their young and only occur during the breeding season. Unmated males associate primarily with other bachelors, and male-female interactions are limited to the breeding season (Despard Estes, 1991). Steppe polecats often live in the same burrow for many years, however, local migrations may occur in response to deep snow or lack of food. They are nocturnal, and although most individuals prefer staying close to home, they can travel up to 18 km to find food during the evening.They are exceptionally agile and greatly depend on their sense of hearing and smell. They can leap up to one meter at a time and appear to follow a random walk trajectory while searching for prey (Nowak, 2005). (Despard Estes, 1991; Nowak, 2005)

Steppe polecats, especially females, tend to stay in the same burrow for many years. Males occasionally browse other burrows in search for estrous females. While hunting, individuals leave their burrows and may travel up to 18 kilometers in one night (Nowak, 2005). The average territory size of steppe polecats is unknown. (Nowak, 2005)

Steppe polecats use chemical cues to communicate with con- and heterospecifics. When threatened or excited, they secrete a foul odor from their anal gland, which they also use to mark territorial boundaries and colonies. Chemical cues are also used for identifying estrus females, territorial boundaries, and sensing danger. In addition to chemical cues, steppe polecats use visual and auditory cues. When threatened, their hair stands erect and they may stare, snap, bite, hiss, or scream to deter a potential threat. Steppe polecat males also use vocalizations to attract potential mates and to signal dominance. Finally, pups use a variety of vocalizations to communicate with mothers and siblings (Despard Estes, 1991). (Despard Estes, 1991)

Steppe polecats are nocturnal and do most of their hunting at night (Nowak, 2005). Although they feed on birds, reptiles, insects, and fruit, their primary prey are rodents, which constitutes nearly 80% of their diet (Wang et al., 2006; Wolsan, 1993). Occasionally they store prey carcasses in their burrow for later consumption (Nowak, 2005). (Nowak, 2005; Wang, et al., 2006; Wolsan, 1993)

Humans hunt steppe polecats for food and fur and are their primary predator. They emit a foul odor when threatened, which is secreted from the anal scent glands (Van den Brink, 1977). (Gerard, 2008; Van den Brink, 1977)

Steppe polecats help control rodent populations, which can carry dangerous parasites or be important disease vectors (Nowak, 2005). They also host a number of different parasites, including Isospora eversmanni, Eimeria ictidea, Isospora pavlowskyi, and Yersinia pestis, the bacterium known to cause the plague. (Nowak, 2005)

Steppe polecats play an important role in controlling rodent populations, which can be agricultural pests or vectors for disease. In addition, they are trapped for their meat and fur throughout eastern Europe and central Asia (Nowak, 2005). (Nowak, 2005)

Steppe polecats are a known reservoir or Yersinia pestis, the bacterium known to cause the plague (Duszynski, et al., 2000). Fortunately, interactions between steppe polecats and humans are very rare. (Duszynski, et al., 2000)

According to the IUCN, steppe polecats are a species of "least concern". However, they are listed as vulnerable in the Red Data Book of Ukraine. The subspecies Mustela eversmanii amurensis is listed in the Red Data Book for Russia and China, due to over hunting and habitat loss, respectively (IUCN, 2010). They are protected under Appendix II of the Bern Convention (Mitchell-Jones et al., 1999). ("International Union for Conservation of Nature and Natural Resources (IUCN).", 2010)