Spring Foods of Snow and Canada Geese at James Bay

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Abstract
Foods of migrating lesser snow geese (Chen c. caerulescens) and migrating and prenesting Canada geese (Branta canadensis interior) were studied in the springs of 1976 and 1978-80 on the west coast of James Bay. Nearly 75% by weight of foods of both species were grasses and sedges, but proportions of plant taxa and parts varied. The diet of Canada geese was 60% shoots, 20% roots, and 20% seeds, whereas shoots and roots each constituted 50% of the snow goose diet, and seeds were rarely eaten. Perennating bulbs of the arrowgrass (Triglochin palustris) were the most strongly selected food item of snow geese, as in the autumn. The diet of roots and newly emerging shoots, in which nutrients are concentrated and easily digested, allow snow geese to replenish and augment body reserves depleted during migration. This, in turn, is likely to be an important positive modifier of subsequent reproductive output.