No abstract

No abstract

We describe a rare case of incestuous broods of Whooper Swan Cygnus cygnus in Świętokrzyskie province, Poland. A sibling pair laid eggs and hatched young at the same site in 2010 and in 2011, nine kilometres from their own hatching place. Both broods were unsuccessful; the young died before autumn. We assume that the key factors explaining the inbreeding were the small local population and that Whooper Swans tend to disperse over short distances.

No abstract

This study was carried out in the uplands of southern Poland (the centre of the study area: 50°45ʹN, 19°50ʹE) on an area of ca. 110,000 ha, including 30 fishpond complexes (Włoszczowa Basin Important Bird Area; Dudzik et al.,