Possible effects of nest predation on the breeding success of Ferruginous Ducks Aythya nyroca

Abstract

To investigate whether nest predation can influence the breeding success of Ferruginous Ducks Aythya nyroca, artificial nests were used in Nagyberek, the strictly protected swamp pond of the Juniper Woodland Nature Conservation Area (Somogy county, south Hungary). Experimentation lasted for 4 weeks, a similar length of time to the incubation period of Ferruginous Ducks. After 1 week, 80% of nests were intact, after 2 weeks only 46%, and after 3 and 4 weeks only 2% remained undamaged. Nest survival rates were not affected by the width of the sedge stands, but as water levels surrounding nests decreased, nests became more accessible to Wild Boar Sus scrofa and other land mammal predators, which increased the rate of predation. Artificially maintaining water levels would not only decrease the predation rate of nests, but would also maintain feeding areas for ducks. Wild Boar were the main cause of clutch loss in this area, and therefore by management measures, such as a reduction in their abundance or attracting them away from potential nesting sites by providing food elsewhere, the breeding success of the Ferruginous Ducks may be further improved.