The effect of neck collars on the behaviour, weight and breeding success of mute swans Cygnus olor

Neck collars were used as an individual marking technique in a population study of wild mute swans on South Uist, Scotland, from 1978-82. This was the first time this method of marking birds had been extensively used in Britain. Collars made of laminated plastic were fitted to over 650 swans during the moult and brood catches. Collars did not affect frequency of feeding, but collared birds upended less often than uncollared birds at both sites. The weights of collared birds however were not different, and neither was their breeding success. -from Authors