Effects of experimental land management on habitat use by Eurasian Stone-curlews

Effective conservation is often informed by focal species studies to identify beneficial land management interventions. For nocturnal or cryptic species, quantifying habitat use across individually marked animals can allow unbiased assessment of intervention efficacy and identify other important habitats. Here, using a landscape-scale experiment, we examine whether interventions intended to create nesting habitat for the largely nocturnal Eurasian Stone-curlew Burhinus oedicnemus within semi-natural grassland also provide foraging habitat. GPS loggers were fitted to five adult Stone-curlews during the breeding season within an extensive area of semi-natural grassland (3850 ha, hereafter 'grassland'), surrounded by a mosaic of arable cropland (total study area 118 600 ha). The largely closed-sward grassland was diversified by experimental ground-disturbance plots (the intervention) prior to this study. We used the GPS fixes to identify 1881 foraging locations (510 during nesting and 1371 post-breeding) across the grassland and surrounding landscape. Most foraging locations were close to the nest-site during the nesting period (90% within 1 km) or day-roost during post-breeding (90% within 5 km), but birds travelled up to 4.1 km from these sites during nesting and 13 km post-breeding. Stone-curlews were two- (by night) or three-times (by day) more likely to select disturbed-grassland over unmodified grassland for foraging during nesting, and c. 15 times more likely to do so post-breeding. Spring-sown crops and pig fields or manure heaps were also selected over grassland for nocturnal foraging. Given that central place foraging occurs in this species, conservation efforts that promote breeding attempts through ground-disturbance should ensure suitable foraging habitat is near the nest (<1 km). Creating multiple areas of disturbed-ground close to the edge of large grassland blocks can provide a network of nesting and foraging habitats, while allowing access to foraging habitats on the surrounding arable farmland. Similar interventions may benefit other disturbance associated grassland waders.

Automated summary

By tracking Eurasian Stone-curlews with GPS, researchers found that the birds prefer diverse grassland habitats during breeding season and search for food near their nest sites. During nesting, the Stone-curlews showed a preference for disturbed grassland for foraging, and also selected spring-sown crops and areas near pig fields for nocturnal feeding in the post-breeding period.