American Marten - Food Habits

Food Habits

American marten are opportunistic predators, influenced by local and seasonal abundance and availability of potential prey. They require about 80 kcal/day while at rest, the equivalent of about 3 voles (Microtus, Myodes, and Phenacomys spp.). Voles dominate diets throughout the American marten's geographic range, though larger prey—particularly snowshoe hares—may be important, particularly in winter. Red-backed voles (Myodes spp.) are generally taken in proportion to their availability, while meadow voles (Microtus' spp.) are taken in excess of their availability in most areas. Deer mice (Peromyscus maniculatus) and shrews (Soricidae) are generally eaten less than expected, but may be important food items in areas lacking alternative prey species. Birds were the most important prey item in terms of frequency and volume on the Queen Charlotte Islands, British Columbia. Fish may be important in coastal areas.

American marten diet may shift seasonally or annually. In general, diet is more diverse in summer than winter, with summer diets containing more fruit, other vegetation, and insects. Diet is generally more diverse in the eastern and southern parts of American marten's distribution compared to the western part, though there is high diversity in the Pacific states. American marten exhibit the least diet diversity in the subarctic, though diversity may also be low in areas where the diet is dominated by large prey species (e.g., snowshoe hares or red squirrels).

American marten may be important seed dispersers; seeds generally pass through the animal intact, and seeds are likely germinable. One study from Chichagof Island, southeast Alaska, found that Alaska blueberry (Vaccinium alaskensis) and ovalleaf huckleberry (V. ovalifolium) seeds had higher germination rates after passing through the gut of American marten compared to seeds that dropped from the parent plant. Analyses of American marten movement and seed passage rates suggested that American marten could disperse seeds long distances: 54% of the distances analyzed were >0.3 mile (0.5 km).