A preliminary evaluation of the performance of passive integrated transponders and metal tags in apopulation study of the flatback sea turtle, Nataor depressus

Abstract

Marking of nesting female Natator depressus with passive integrated transponders (PITs) at the major eastern Australian rookery of Wild Duck I. was initiated in 1989. The failure rate of PITs after two years was calculated and compared with loss probability estimates calculated for conventional metal tags on the basis of 1979-91 data. PITs compared favourably in the short period of evaluation with an 8% loss of identification after two years (n=37). Loss of metal tags was variable between metals and tagging positions, with titanium tags applied to the axillary position of the front flippers being the most effective in the long term. Factors peculiar to this species that affect loss of metal tags and prospects of PIT performance in the long term are discussed.