Effect of non-inversion tillage on field usage by UK farmland birds in winter

Capsule Several guilds of wintering farmland birds showed preferences for cereal fields established by non-inversion tillage, rather than ploughing. Aims To compare the effects of cereal crop establishment methods using non-inversion tillage and ploughing on field use by wintering farmland birds. Methods Cereal fields on commercial farms, established by non-inversion tillage or conventional ploughing, were censused for birds over the winter months of 2000 to 2003, using standard whole-field count methodologies. Multivariate logistic regression methods were used to assess the difference in bird use between fields with the two crop establishment methods, whilst controlling for the effects of a variety of other variables. Results In late winter, Skylarks Alauda arvensis, granivorous passerines and gamebirds occupied a greater proportion of fields established by non-inversion tillage than conventional tillage. Conclusions As well as documented benefits for resource protection, such as soil and water conservation, non-inversion tillage methods appear to enhance suitability of winter cereal fields for forraging birds. Future studies could usefully identify the mechanisms, in terms of food abundance and sward structure, which drive these preferences.