Habitat selection and diet of lapwing Vanellus vanellus chicks on coastal farmland in S.W. Sweden.
Abstract
Habitat use by colour-marked lapwing (Vanellus vanellus) broods was studied at three coastal farmland sites in SW Sweden from 1987 to 1990. Initial brood movements between nest sites and home ranges used for chick-rearing varied between 7 and 332 m. At all sites, the proportions of habitats within lapwing home ranges differed from availability. Seashore pasture was relatively the most used habitat. Lapwings selected home ranges with lower proportions of arable fields and moist pasture relative to seashore pasture, and at two sites also to the shore, than expected if choice was due to availability. Lapwing broods did not select feeding habitats in relation to availability. Feeding on seashore pasture, and at one site also on the shore, occurred more frequently than expected relative to the use of arable fields and moist pasture. Foraging on the shore was constrained by variation in seawater level. Broods from nests on arable fields left the nest site habitat, and used the same feeding habitats as broods hatched on pastures. Chicks fed on a wide variety of prey organisms, representing terrestrial, marine and freshwater invertebrates. Sampling of potential food supply suggested that numbers and biomass of invertebrates included in the chick diet were greater on a seashore pasture than on an adjacent moist pasture. Loss of important chick foraging habitats and isolation of nest sites and chick-rearing habitats, caused by changes in agricultural land use, have probably contributed to the decline of lapwings breeding on farmland in Europe. The results are related to conservation of this and other waders breeding on farmland.