The utilization of heather moorland by territorial Red Grouse Lagopus lagopus scoticus

Although the breeding density of Red Grouse Lagopus lagopus scoticus is related to the density of burned patches of heather Calluna vulgaris , territories appear to offer surplus food, and other factors, especially the risk of predation, may be important. In order to determine how Red Grouse make use of heather moorland, an individually marked population was studied on a moor in northeast Scotland from 1992 to 1994. Territorial birds preferred stands of tall heather during the daytime in autumn and winter, but in spring they increased their use of heterogeneous heather/grass mixtures. Furthermore, in spring, females showed a very strong affinity for edges between heather stands of different ages, where they had easy access to nutritious young heather and good cover. When near the vegetation edge, territorial birds spent most time on the side of the edge providing greater cover. Broods occupied ranges in areas with rather more old heather and with more edge than was available over the entire study site. Within their ranges though, broods clearly preferred heterogeneous areas during the first month after hatching, and showed a further preference for vegetation edge. Their behaviour changed during the second month after hatching, when they utilized tall heather to a greater extent, but edge remained important.