The fate of plastic leg rings used on geese and swans

摘要: Engraved plastic leg rings have been placed on Barnacle Geese, Bewick's Swans and Whooper to facilitate long-term studies of individual birds within the different populations. The rate wear for Goose was 0.23 mg/year which, average, less than 1% initial weight ring. mean ring loss just 0.35% per annum but groups swans broke or lost their at rates varying from 5.8% female 27.6% male with Vynalast during first two years after ringing. In some cases, type material used make swan affected lifespan; proved durable Darvic there no significant difference in Swans. more likely break lose Swans, irrespective rings. minimum lifespan recorded fitted significantly shorter males females between sexes regarding Swan Some individuals (predominantly male) were others. Different factors thought influence included diameter (larger had a lower survival rate), size strength birds.