Causes of mortality among wild swans in Britain

Abstract

Post mortem data from 366 dead swans recovered from the wild between 1951 and 1989 were examined. The main causes of death were flying accidents (accounting for 22% of adult deaths and 23% of juveniles), lead poisoning (in 21% of adults and 10% of juveniles), trauma (in 8.4% of adults, 8.7% of juveniles and 30% of Mute Swan downies), tuberculosis (6.0% of adults and 1.0% of juveniles) and aspergillosis (3.8% of adults and 7.7% of juveniles).