Modelling the relationship between bird population variables and hedgerow and other field margin attributes. I. Species richness of winter, summer and breeding birds.
Abstract
An understanding of how farming practices in adjacent fields and the dimensions of the hedge and other boundary components affect birds is essential for efficient conservation of field boundaries. This paper is based on surveys of field boundary transects at 2 sites in East Anglia, UK - near Huntingdon (1983-85) and at Swavesey (1985-87). Regression models were used to relate bird species richness in winter and summer to field boundary attributes (including adjacent land use). Bird variables were positively correlated with the physical size of the hedge, the numbers and height of the trees, and adjacent permanent pasture. Ditch and verge dimensions played a statistically significant but relatively less important role. Field boundary management options beneficial for bird conservation and with relatively little agricultural cost are presented.