SEED DENSITY, COVER, PREDATION AND THE DISTRIBUTION OF BIRDS IN A BEECH WOOD IN SOUTHERN SWEDEN

Abstract

SUMMARYThe distribution of six species of birds within a beech wood was analysed in two winters when beech seeds were abundant. All species were concentrated in patches where seed density was high in one winter, but only two showed a similar distribution in the second winter. The distribution of the other four species, three tits Parus spp. and the Nuthatch Sitta europaea, was positively correlated with low cover. Cover was inversely correlated with seed density. Bird predators were recorded many times during the second winter but not at all during the first winter. It is suggested that predator avoidance was more important than food density for some species in the second winter.The relationships between bird density and both food and cover were sigmoid in shape.The proportion of the seed crop consumed by the birds was estimated at about 4.5%, which was probably more than the amount consumed by mammals. The Woodpigeon Columba palumbus (which took 44% of the total seeds consumed by birds) and the Brambling Fringilla montifringilla (33%) were the most important seed consumers among the birds.