their body size. One review reports population densities ranging from 0.4 to 2.5 individuals/km2. Population density may vary annually or seasonally. Low population densities have been associated with a low abundance of prey species. Home range size of the American marten is extremely variable, with differences attributable to sex, year, geographic area, prey availability, cover type, quality or availability, habitat fragmentation, reproductive status, resident status, predation, and population density. Home range size does not appear to be related to body size for either sex. Home range size ranged from 0.04 sq mi (0.1 km2) in Maine to 6.1 sq mi (15.7 km2) in Minnesota for males, and 0.04 sq mi (0.1 km2) in Maine to 3.0 sq mi (7.7 km2) in Wisconsin for females. Males generally exhibit larger home ranges than females, which some authors suggest is due to more specific habitat requirements of females (e.g., denning or prey requirements) that limit their ability to shift home range. However, unusually large home ranges were observed for 4 females in two studies (Alaska and Quebec). Home ranges are indicated by scent-marking. American marten male pelts often show signs of scarring on the head and shoulders, suggesting intrasexual aggression that may be related to home range maintenance. Home range overlap is generally minimal or nonexistent between adult males but may occur between males and females, adult males and juveniles, and between females. Several authors have reported that home range boundaries appear to coincide with topographical or geographical features. In south-central Alaska, home range boundaries included creeks and a major river. In an area burned 8 years previously in interior Alaska, home range boundaries coincided with transition areas between riparian and nonriparian habitats. Description The American marten is a long, slender-bodied weasel about the size of a mink with relatively large, rounded ears, short limbs, and a bushy tail. American marten have a roughly triangular head and sharp nose. Their long, silky fur ranges in color from pale yellowish buff to tawny brown to almost black. Their head is usually lighter than the rest of their body, while their tail and legs are darker. American marten usually have a characteristic throat and chest bib ranging in color from pale straw to vivid orange. Sexual dimorphism is pronounced, with males averaging about 15% larger than females in length and as much as 65% larger in body weight. Total length ranges from 1.5 to 2.2