Habitat selection of foraging male Great Snipes on floodplain meadows: importance of proximity to the lek, vegetation cover and bare ground

摘要

Drainage of wetlands and agricultural intensification has resulted in serious biodiversity loss in Europe, not least in grasslands. Consequently, many meadow birds have drastically declined, and the habitats they select for breeding currently rely on land management. However, the selection of habitats maintained by agriculture may contribute to reduced fitness and thus remain maladaptive for individuals, which makes conservation challenging. An understanding of the relationships between species' habitat selection, food supply and land management in the context of species' behaviour is therefore crucial for conservation. Lowland populations of Great Snipe Gallinago media are currently declining at a moderate rate, causing a conservation concern. We examined the daytime site selection (assumed as foraging sites) and food supply of radiotracked Great Snipe males breeding on a floodplain in NE Poland. Foraging sites were classified at micro- and macro-scale levels using the logistic regression in a use-availability design. On the micro-scale level, males selected moderate sward height and density, and a large amount of bare ground patches, and the importance of these increased as the breeding season progressed. On the macro-scale level, these conditions were associated with (1) meadows mown twice per season and grazed thereafter (associated with the most abundant food resources - earthworms) and (2) extensively managed pastures, suggesting the importance of grazing. Abandoned or late-mown meadows under agri-environmental schemes (AES) were avoided by foraging males. However, parcels with delayed mowing offer safe breeding sites for females nesting close to leks, unlike land-use types preferred by foraging males, which may act as an ecological trap. Effective conservation of Great Snipes on floodplain meadows requires precisely targeted AES schemes that will provide a mosaic of intensive and extensive land-use patches in the vicinity of identified leks.