Patagial Tags - Do Benefits Outweigh Risks to the Animal

Abstract

The use of patagial tags to individually mark animals, particularly birds, is a recent method of identification. Disadvantages to the animal may outweigh any benefits to the researcher. I compare the rate of return to the breeding area of leg-banded and patagial tagged Carnaby's cockatoos, Calyptorhynchus funereus latirostris. Adult females which were patagial tagged had a first year rate of return of 59% (N= 172) compared with 100% (N= 12) for females with leg bands. Immature females which were patagial tagged before fledging had a return rate to breed in the study area (4 years later) of 1.3% (N= 150) compared with 12.7% (N=71) for leg-banded individuals. The data used in these comparisons were not collected in the same years but they suggest that patagial tags may increase mortality; in the case of Carnaby's cockatoo predation is the most likely cause. This possible increased mortality indicates that data gathered from resighting of patagial-tagged individuals should not be used in life tables and calculations of 'normal' survival rates until such effects can be discounted. A strong case for the use of patagial tags should be made before they are used on rare, vulnerable or endangered species.