A team studying King penguins on Possession Island has concluded that banding penguins' flippers, a common practise in scientific studies, both increases mortality and decreases reproduction of the birds.
The study, just released in Nature, found that in a comparison of 50 banded and 50 unbanded penguins, the banded birds on average had 40 percent fewer chicks and a 16 percent lower survival rate over a ten-year period.
Author Yvon Le Maho from the University of Strasbourg in France, said the practise should be abandoned and alternative methods found, "certainly as a precautionary principle".
Climate change studies considering its effect on ecosystems have in the past been cited as evidence that minor levels of warming would result in large declines in penguin numbers, but these new findings make such extrapolations impossible to confirm.
