Tagging a penguin's wing with a research tag changes their drag coefficient, resulting in altered social behaviour, most notably less success in breeding.
As well as hindering conservation efforts, the penguins' poor breeding success may also mean that birds tagged in previous experiments have yielded misleading scientific data.
"We may have to reconsider our present knowledge on the life-history traits of penguins, such as breeding success and chick survival, which over the years has been drawn almost entirely from flipper-banded birds," warn Gauthier-Clerc and his colleagues in their paper in Biology Letters.
