Breeding ecology of the Mallard on a flooded area of the Warta river mouth, Poland

Abstract

Mallard Anas platyrhynchos showed a high adaptability in flooded areas at the confluence of the Warta and Oder Rivers, Western Poland, using trees as nesting sites and moving to adjacent habitats during extreme flooding. Nesting losses, which ranged from 76-79% in natural nests and from 51-69% in nest baskets, had the greatest effect on population productivity. Duckling mortality (3-35%), partial egg loss (8.3-12.5%), and changes in clutch size were of less importance. Predation was the main factor limiting Mallard reproduction, but size of breeding population depended also on changes in habitat conditions. The calculated productivity was 2.2-2.7 flying young per breeding female for natural nests and 3.6-3.7 for nest baskets.