Corncrakes returning to Ireland and Scotland to breed are vulnerable to chick mortality from early mechanical hay cutting before their young can escape.
Corncrake chicks and brooding females struck by mechanical cutting machinery suffer acute traumatic injury and death. The intensification of silage cutting, which occurs earlier in the season than traditional hay cutting, coincides with periods when chicks are flightless and entirely dependent on vegetation cover. Individual birds caught in cutting machinery experience violent trauma. The loss of meadow complexity from agricultural simplification leaves birds with fewer escape routes.