Winter bird communities in woodland in the Forest of Dean, England, and some implications of livestock grazing

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Abstract
Winter bird communities, sampled by transect methods, were compared between 9 woodland sites (1 ungrazed oak, 4 grazed oak, 4 grazed conifer) in the Forest of Dean Gloucestershire, during 2 winters (1984/85 and 1987/88). Ungrazed oak woodland had the highest counts of individual birds in both years. More species occurred in oak woods than in conifers. Ordination of the combined data from the 2 winters illustrated a consistent gradient of bird species composition (after the exclusion of 2 flocking species, Woodpigeon and Chaffinch), from evergreen coniferous to deciduous broadleaf. Green and Great-spotted Woodpecker, Hawfinch, Field fare, Brambling, Great Tit, Magpie and Siskin occurred largely towards the deciduous broadleaf end of the gradient. Classification of the bird data split the sites firstly into deciduous broadleaf and evergreen coniferous. In further sub-divisions, one group had tree species composition consisting largely of ungrazed oak for which the indicator bird species was Hawfinch. The indicator species of the grazed conifer group were Blue Tit, Goldcrest, Coal Tit and Long-tailed Tit. The tree species composition for the 5 final groups was then related to the number of bird species in them. In both years the mean number of species in the groups increased with an increase of the dominance of oak, with the highest value in ungrazed oak. The implications of the development of further ungrazed areas for conservation purposes are discussed.