Growth and Survival of Willow Grouse Chicks in Relation to Home Range Size, Brood Movements and Habitat Selection

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Abstract
Spacing, movements and mortality of Willow Grouse Lagopus l. lagopus broods were studied using radio-telemetry during three breeding seasons on a small island in northern Norway. Chicks survived worse during two cold summers with few insects than in a warm summer with many. In cold weather, many died at 3-5 days. Broods selected forests, bogs and fens, and shore vegetation which supported the largest number of insects. Mean differences between years in spacing and brood movements were small. Within year, growth was slower and survival lower among those broods with the greatest mobility and largest home ranges. Broods occupying small home ranges restricted their movements to areas especially rich in insects, whereas longer movements were made in poorer habitats. There appeared to be a dominance hierarchy among broods which effectively prevented them from occupying the same areas.