Crex

Abstract: Summary As a double-brooded species inhabiting grassland habitats subject to mowing and located at different elevations, the Corncrake Crex crex in the Alps is potentially affected by changes in its breeding habitat within a season, thus leading to shifts in occurrence and habitat association, with potentially relevant consequences for conservation. We investigated Corncrake abundance in four sites in Trento province (N Italy); two sites were defined as ‘low elevation’ (mean elevation 975 m and 976 m a.s.l., respectively) and two as ‘high elevation’ (mean elevation 1,173 m and 1,177 m). The number of calling males showed a clear variation in relative abundance between early and late periods of the breeding season; in particular, at low elevation sites, abundance decreased from the early to late periods, while the opposite was recorded at high elevation sites. A mixed model suggested that the number of males decreased in the second half of the breeding season and at high elevations, and changed according to mid-season altitudinal shifts. Conservation strategies for this species should take into account the mid-season territory shift.

Abstract: Most Corn crake territories were located in hayfields; these and marshes were the preferred nesting habitat. Since 1982 there has been a major reduction in Corncrake numbers on Canna. Although there have been minor habitat changes, the limited data on brood size and number suggest that much of the habitat on the island is still suitable for Corncrakes. Information from retrapping calling adults showed a very low return rate, as has been found in Sweden. The recent decline may be due to higher mortality on migration, as conditions in the breeding area on Canna and the wintering areas do not appear to have changed significantly.