Hunting disturbance and the timing of autumn migration in anas species

Abstract

In Europe, waterfowl hunting is a popular recreational activity, especially in waterfowl staging and wintering areas, but also in breeding areas such as Finland. This paper gives an account of hunting disturbance, timing of autumn migration and refuge use in Anas species in eutrophic wetlands in central Finland (63°N, 27°E) during 1995-1999. Based on the timing of migration, duck species may be divided into early and late migrants. In two lakes (total area 2.2 km2) which were monitored on a weekly basis during 1995-1998, numbers of late migrants, i.e. mallard Anas platyrhynchos, teal Anas crecca and wigeon Anas penelope, increased towards the opening of hunting season on 20 August, whereas shoveler Anas clypeata, pintail Anas acuta and garganey Anas querquedula migrated early, and peak numbers of these species occurred already in the beginning of August. Consequently, in Finland's inland lake area, hunting disturbance relates differently to early and late migrating species. Immediately after the opening of the season the numbers of dabbling ducks collapsed and the average numbers in the wetlands were only 9.3% of the numbers present at the end of the protection period in 1995-1998. A corresponding decrease in numbers occurred in 13 lakes (total area 8.5 km2) in the Finnish inland lake district in 1999. After the beginning of the open season numbers of wigeon, teal and mallard decreased in unprotected areas, but increased in a refuge area. In Finland, refuge areas with high-quality foraging and moulting habitats for waterfowl are few, so a network of waterfowl reserves could mitigate the effects of hunting disturbance.