The metal tags attached the flippers of penguins to identify and track them for scientific studies can cause long-term harm to the birds and even limit their chances of survival, according to a new study. A 10-year Antarctic study found that king penguins that had been tagged produced 39 percent fewer chicks and had a 16 
percent lower survival rate. And tagged penguins spent 12.7 days on foraging trips away from home compared with 11.6 days for non-tagged animals, a possible indication that the tags slowed their swimming. Penguin chicks eat only when a parent returns from these foraging trips, which can take them hundreds of miles away from their breeding sites. “One or two days is a huge difference,” said Claire Saraux, an ecologist from the University of Strasbourg and France’s CNRS Network and co-author of the study published in the journal Nature. “From an ethical point of view, I think we can’t continue to band.” According to a 2000 study, more than 36,000 penguins were tagged for research between 1988 and 1996.
Wikimedia