Selection of foraging habitat and nestling diet by Meadow Pipits Anthus pratensis breeding on intensively grazed moorland

摘要

Capsule Foraging sites with low vegetation height and density, but with high arthropod biomass, areudselected.udAims To test the hypothesis that on intensively grazed moorland, breeding Meadow Pipits forage forudnestling food where arthropod prey are most readily available, and therefore that foraging site choice isuda function of prey abundance and vegetation structure.udMethods Observations of adults provisioning nestlings were made from hides positioned close to 19udnests within grazed, 3.3-hectare experimental plots at Glen Finglas, Scotland. Vegetation height anduddensity and arthropod abundance from mapped foraging sites were compared with control sites. Preyuditems fed to nestlings were quantified and compared with their relative abundance.udResults Meadow Pipits selected foraging sites with significantly lower vegetation height and density, but withudsignificantly higher arthropod biomass. Our data suggest that within foraging sites, Meadow Pipits selectudparticular prey types to provision nestlings, in particular, Lepidoptera larvae, adult Tipulidae and Arachnida.udConclusions In intensively grazed upland systems, it appears that Meadow Pipits select foraging sitesudthat optimize total food abundance and accessibility. In order to understand how anticipated changesudto livestock farming in Europe will affect grassland birds, we recommend that future studies shouldudinvestigate the foraging and vigilance behaviour, diet composition and breeding success of a variety ofudbird species provisioning nestlings under a range of livestock management scenarios.