2,    adults,    Aix,    anatids,    animals,    attacking,    attacks,    aves,    birds,    bites,    biting,    canards,    copulates,    copulating,    copulation,    drakes,    ducks,    females,    format,    lakes,    laterally,    males,    move,    movement,    moves,    outdoors,    outside,    pair,    river,    Sex,    swimming,    swims,    waterbirds,    waterfowls,