Effect of dairy farm management on Swallow Hirundo rustica abundance in The Netherlands

Abstract

Capsule Dairy farm management methods have no influence on numbers of Swallow breeding pairs. Aim To identify differences in Swallow abundance between organically and conventionally managed dairy farms, by examining three factors: farm buildings, food availability and farmer attitudes to Swallows. Methods Organic and conventional dairy farm holdings were compared in pairwise fashion. On visits to individual farms the number of occupied Swallow nests was counted, the number and type of farm buildings recorded, food availability assessed and the farmer's attitude gauged via a questionnaire. Results No significant difference was found in the number of Swallows on organic and conventional farms. Nor was there any significant difference in food availability or farmer attitude between the two types of holding. On conventional farms there were significantly more buildings qualifying as preferential Swallow breeding sites, but this did not result in more Swallows on these holdings. Conclusions Our results show that the adopted regime of dairy farm management (conventional versus organic) has no influence on the number of breeding pairs of Swallows.