Occurrence of Corncrakes Crex crex in mosaic farmland landscapes in south-central Sweden – effects of habitat and landscape structure

Abstract

SummaryMost studies of Corncrakes have been conducted in grasslands used for hay-cutting, and earlier hay-cutting has been suggested as the main cause of population decline in this species. Less is known about habitat preferences in relation to other land-uses and landscape structure. This paper investigated habitat composition and landscape structure in territories and at random sites in arable fields and meadows in south-central Sweden. Calling Corncrakes preferred sites with tall vegetation, moist ground, and locations close to ditches (55% of territories). Suitable conditions occurred on abandoned unmanaged wet meadows (31% of territories), mown wet meadows (14%), leys (30%) and non-rotational set-asides (15% of territories). Corncrakes avoided annual crops and other crops with short vegetation in the spring. Cutting of vegetation before mid-July was recorded in 21% of the territories and resulted in 100% abandonment of these sites. In contrast to many other ground nesting farmland birds, Corncrakes did not avoid forest edges (42% of territories within 100 m of edges). A strategy to conserve Corncrake populations should focus on maintenance of moist natural and sown grasslands (unmanaged or mown late) with tall vegetation and prevention of succession to woodland. Target areas should be in forested landscapes, because many other meadow birds that are more dependent on management (e.g. yearly mowing or grazing) prefer open landscapes.