Summer utilization of Oilseed Rape by Reed Buntings Emberiza schoeniclus and other farmland birds

Abstract

Capsule Oilseed Rape was the preferred breeding season habitat for Reed Buntings on arable farmland and reduced this species' dependence on wet features. Aims To identify preferred breeding season habitats for Reed Buntings on arable farmland and factors influencing the attractiveness of Oilseed Rape. Methods Summer usage of arable fields by nesting and foraging farmland birds was assessed from a random sample of arable fields in Nottinghamshire, England. Generalized linear models were used to identify habitat and landscape predictors of Reed Bunting breeding density and of foraging by other farmland birds. Results Occupancy rates and densities of Reed Buntings were approximately four times greater in Oilseed Rape fields than in cereals or set-aside. Reed Buntings commonly nested in Oilseed Rape fields more than 100 m from wet features, but the same was not true of cereals or set-aside fields. Usage of Oilseed Rape by farmland birds was promoted by weediness, bare patches and nearby wet features, and reduced by grass margins, tall field boundaries and electricity pylons. Conclusions Oilseed Rape is one of the most important breeding season habitats for Reed Buntings in lowland Britain, providing a relatively rich source of seed and invertebrate food and possibly protection from nest predators. Breeding in Oilseed Rape reduces the dependence of Reed Buntings on nearby wet features.