Habitat use by different‐aged duck broods and juvenile ducks

Abstract

Habitat use by different‐aged broods and juveniles of teal Anas crecca, mallard A. platyrhynchos and goldeneye Bucephala clangula was investigated in southern Finland during 1988–1993. The study focused on within‐lake habitat use and the use of flooded wetlands. Downy ducklings of all three species showed significant preference for Carex‐stands. As the dabbling ducks grew older, their habitat use diversified, juveniles in particular also made considerable use of floating vegetation. Conversely, habitat use by goldeneye became more uniform: goldeneye juveniles were almost exclusively seen in open‐water and floating vegetation habitats. All three species, but especially teal, used flooded areas intensively. Two thirds of teal downy broods were seen along flooded shores which comprised only seven percent of all shore habitats. Preliminary data suggested that the preferred habitat types, Carex and flooded shores, harboured more nektonic invertebrates and emerging insects than did the other shore types.