Tools in waterfowl reserve management: effects of intermittent hunting adjacent to a shooting-free core area

摘要

We explored how waterfowl in a large Danish coastal wetland responded to one day of marsh shooting at intervals of three weeks (1998), two weeks (1999), and one week (2000 and 2001). Shooting took place around sunset on a section of salt marsh that usually is part of a large shooting-free refuge. The behavioural response of waterfowl was recorded, and all waterfowl were counted on the day of the hunt and on the first and second day after each hunt. The wildfowl responded to the first 1-7 shots by moving into the open water parts of the refuge (dabbling ducks) or to sites > 8 km away (geese and waders). When the salt marsh was flooded early in autumn 2001, wigeon Anas penelope, teal A. crecca and lapwing Vanellus vanellus restricted their response tomovements to other non-hunted parts of the salt marsh. On the first day after the hunts, mallard A. platyrhynchos occurred in significantly lower numbers both on the adjacent shallow and on the salt marsh. Wigeon numbers on the shallows were not affected by shooting, though they returned in lower numbers to the salt marsh on the first day after the hunts in 1998-2000, but not after the hunts in 2001. A similar pattern was observed in teal numbers on the salt marsh. We conclude: 1) that shooting lead toshort-term displacements of dabbling ducks, 2) that the response of wigeon and teal varied depending on prevailing conditions on the salt marsh, 3) that intermittent regulation of marsh shooting was a management tool that ensured that waterfowl continued to exploit the area shot over on days when no shooting took place, and 4) that the relatively weak responses were linked to the existence of an extensive refuge adjacent to the area with marsh shooting.