Experimental refuges for migratory waterfowl in Danish wetlands. II. Tests of hunting disturbance effects

摘要: 1. In most situations that have been studied, the creation of refuge areas for migratory waterfowl has generally increased number using a site. However, experimental evidence to show increases were caused by reduced disturbance and not confounding factors, e.g. improvement habitat quality sites or general population increases, is lacking. 2. two Danish coastal wetlands, hunting was critical source autumn-staging (Madsen 1998). To test whether displaced birds from sites, established, with hunting-free manipulated annually during 4-year period, followed permanent establishments, monitored further 4 years. 3. both areas, experiments showed quarry geese dabbling ducks redistributed according position whereas protected species did not. geese, there 6–8-fold increase in numbers before after experiments; 4–50-fold increase. Dabbling extended staging period into winter. Protected as well goldeneye coot (both species) redistribute; their either fluctuated (2 to > 50 fold). 4. ducks, changes food supplies (of herbivorous species), intensities recreational activities outside weather overall sizes could explain increases. species, coot, trends local accordance some species; others, rate higher than size. 5. richness experiments. This pronounced one where included shallow-watered association salt marshes. 6. It concluded prior experiments, displacement resulting species-poor community. Refuge an efficient management tool improve conservation value biodiversity wetlands importance waterfowl.