Effects of harvesting regime on food availability and cover from predators in capercaillie (Tetrao urogallus) brood habitats

Abstract

Capercaillie (Tetrao urogallus) broods prefer habitats that contain food for the chicks and cover against predators. During the summer 2005, in each of nine areas, three initially similar forest stands were examined: one was harvested by clear-cutting and one by selective cutting, while the last was uncut. Brood habitats in terms of food availability and cover from predators in old forest stands were compared with those in selectively cut and clear-cut stands. The selectively cut forest stands were more open, so the chicks may have been easier to detect by raptors. On the clear-cuts the preferred chick food, Lepidoptera larvae, was less abundant and the measurements suggest that the chicks were easier to detect. If the amount of available brood habitat positively influences chick survival, clear-cutting is likely to decrease chick survival. Selective cutting preserves food availability, but may increase predation by raptors.