Mowing management and density dependence in meadow passerine hatching success

Abstract

Capsule: Improving habitat quality through late or intermittent mowing may increase passerine population density without reducing reproductive success. Aim: To describe the relationship between passerine territory density (TD) and Whinchat Saxicola rubetra and Yellow Wagtail Motacilla flava hatching success, under different management regimes. Methods: TD was defined by the Territory Mapping method in nine sites selected in five French flood plains, in four intermittently mown meadows in Russia and in four additional French sites where mowing was partially postponed. Hatching success was assessed by the observation of prey carrying. Generalized Linear Mixed Models were used to analyse the influence on hatching rates of mowing management, early mowing and TD. Linear Mixed Models were used to study the effect of mowing management on TD. Results: In French early mown meadows, TD affected reproductive success. Higher hatching rates and TD were observed in Russia. Similar results in French study sites with postponed mowing confirmed the influence of mowing management on carrying capacity. Conclusion: In west-European grassland systems, late or intermittently mown patches within or at the edge of meadow areas, with potentially improved invertebrate-prey availability, should help to sustain bird demography and improve the efficiency of current conservation programmes. © 2014 British Trust for Ornithology.