ABUNDANCE AND DISTRIBUTION OF CAPERCAILLIE TETRAO-UROGALLUS IN SCOTLAND 1992-1994

The capercaillie Tetrao urogallus L. is a cryptic forest gamebird whic h has decreased in Scotland, as in much of its range, since the 1970s. Despite previous surveys of the bird's range in Scotland, there was n o assessment of numbers giving confidence limits. Here we establish su ch a baseline against which future estimates may be set. Numbers were estimated from a combination of questionnaires, Geographical Informati on System (GIS) and advanced line transect techniques, using repeatabl e methodology which should be applicable to other cryptic forest speci es. The GIS was used to map capercaillie distribution and relative abu ndance in Scotland. Transects were then placed randomly within the bir d's reported range, stratified by geographical region and estimated ab undance rating. From observations on 426 2-km line transects in winter s 1992-1993 and 1993-1994, the population was estimated to be 2200 bir ds (1500-3200, 95% C.L.) There were approximately twice as many female s as males in the sample. Birds were present from the Forth-Clyde indu strial belt northwards to the Dornoch Firth and from the Central Highl ands eastwards. The main centres of population were in eastern and cen tral Scotland (Deeside, Speyside and Perthshire). The highest densitie s were in native pinewoods (2.7-5.0 birds km(-2)), and the lowest were in thicket and pole/high canopy plantations (0.4-0.9 birds km(-2)). T his information is being used to identify sites for enhancing capercai llie habitat under the Forestry Authority's Woodland Grant Scheme. (C) 1998 Elsevier Science Ltd. All rights reserved.