Breeding bird communities of native pine forest, scotland

Abstract

In view of the 25% loss of native pine woodland in Scotland during the period 1950 to 1986, bird communities breeding in native Scots Pine (Tinus sylvestris) forest at Abernethy, Scotland, are described from species densities estimated by point count methods and individual species densities were compared across gradients of habitat identified by ordination techniques. Thirty-five bird species were recorded with a total density of 29.9 individuals ha 1 of which 8 species, Goldcrest, Chaffinch, Spotted Flycatcher, Coal Tit, Crested Tit, Siskin, Treecreeper and Redstart, constituted 85% of numbers. Detrended correspondence analysis was used to ordinate vegetation at point count locations from which li groups of bird counts were analysed across the habitat gradients. Two axes, representing increasing openness of canopy (axis I) and decreasing shrubbiness (axis II), were identified. Total bird density declined significantly with openness of canopy and increased significantly with increasing (a) pine density, (b) maximum tree height, (c) frequency of dead wood on the ground and in the candpy. Crested Tit, Goldcrest, and Coal Tit showed species-habitat correlations. Crested Tit density for axis 1 was positively correlated with the frequency of dead wood in the canopy. Only Crested Tit showed a habitat association with vegetation variables from axis II: density declined with an increase in percentage cover of the 0.3-1.0 m shrub layer. The management implications of these findings are discussed. © Taylor& Francis Group, LLC.