Seasonal Foods of Adult White-Tailed Ptarmigan in Colorado

May, Terry; Braun, Clait

Abstract: Crop contents of 286 adult white-tailed ptarrnigan (Lagopus leucurus) collected between June 1966 and June 1971 in alpine and subalpine areas of Colorado were analyzed to describe sea sonal trends in food selection. Except in summer, willow (Salix spp.) was the most abundant food. In winter, willow buds and twigs were eaten most often, with mountain dryad (Dryas octopetala) and alder (Alnus tenuifolia) being of secondary importance. In spring, ptarmigan utilized green leaves and flowers of mountain dryad, cinquefoil (Potentilla diversifolia), buttercup (Ranunculus spp.), and snowball saxifrage (Saxifraga rhomboidea), with leaves and buds of willows still being taken most often. Major foods during summer included the seeds and leaves of alpine bistort ( Polygo num viviparum), sedges (Carex spp.), clovers (Trifolium spp.), willows, American bistort (Polygo num bistodoides), mouse-ear (Cerastium spp.), snowball saxifrage, alpine avens (Geum rossii), and mustards (Cruciferae). Early in the fall, willow leaves, buds, and twigs were again utilized most often, with alpine bistort, clovers, blueberries (Vaccinium spp. ), and mouse-ear eaten before they be came unavailable because of increasing snow depths

Seasonal Foods of Adult White-Tailed Ptarmigan in Colorado

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