The most common way of identifying penguins for research does the birds serious harm, according to a new study. Researchers found that penguins given flipper bands had 40% fewer chicks than penguins with implanted transponders and lived shorter lives, the BBC reports. The team believes the tags created extra drag when the birds swim and may attract predators.
The researchers say their findings demonstrate that the use of flipper tags is unethical, and could invalidate many previous penguin studies. Tags should not be used except when the penguin are on land, and "that could still be useful, because I can tell you that when you go into a colony of 50,000 penguins to find yours, it's not easy," the lead researcher says.
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