Agricultural intensification and the timing of breeding of Corn Buntings Miliaria calandra

Aims: To investigate the effect of modern farming practices on the number of Corn Bunting breeding attempts. Methods: We compared the timing of breeding by Corn Buntings on the South Downs, West Sussex, with the habitat composition within 150 m of their nests. Results: Breeding was earlier in areas containing winter-sown wheat and set-aside than in areas containing spring-sown barley. Nests were earlier when cereal crops near the nest were more developed. The presence of unripe grain was a better predictor of the timing of breeding than the height of the crop. Double-brooding was extremely rare and few females re-laid after nest failures. Daily failure probabilities of clutches increased during the season, largely as a result of harvesting operations. Conclusions: Changes in the timing of cereal harvesting and the availability of uncultivated nesting habitat may have reduced the incidence of double-brooding in some intensive arable landscapes. Food availability may also limit the onset of breeding, further reducing the possibility of double-brooding.