Nutritional Ecology of Microtine Rodents: Food Habits of Lemmings near Barrow, Alaska

Abstract

Analyses of stomach contents and feces showed striking differences in the diets of the brown lemming (Lemmus sibiricus) and the collared lemming (Dicrostonyx groenlandicus) near Barrow, Alaska. Brown lemmings ate primarily grasses, sedges, and mosses, whereas collared lemmings ate primarily willow leaves and forbs. Brown lemming diets changed markedly with season and with habitat. Monocotyledons were always the most important food items; in winter and in drier habitats mosses became a more important component of the diet (up to 40%). Among the monocotyledons, brown lemmings consistently preferred tundra grass (Dupontia fisheri), consistently avoided a sedge (Carex aquatilis), and took a relatively constant amount of cottongrass sedge (Eriophorum spp.) no matter what its availability. Differing food habits of lemmings in different habitats may have important consequences for their growth, reproductive performance, and population dynamics.