Study says tracking devices can be harmful to penguins

WASHINGTON - Some scientists studying penguins may be inadvertently harming them with the metal bands they use to keep track of the tuxedo-clad seabirds, a new study says.

The survival rate of king penguins with metal bands on their flippers was 44 percent lower than those without bands, and banded birds produced far fewer chicks, according to new research published Wednesday in the journal Nature.

The theory is that the metal bands - either aluminum or stainless steel - increase drag on the penguins when they swim, making them work harder, the study's authors said.

Author Yvon Le Maho of the University of Strasbourg in France said the banded penguins looked haggard, appearing older than their age.

So studies that use banded penguins - including ones about the effects of global warming on the seabirds - may be inaccurate, mixing up other changes in penguin life with the effects from banding, said Le Maho and colleague Claire Saraux.

Le Maho said this was the first study showing long-term harm from banding penguins.

"There is an ethical question," Le Maho said: "Should we continue" banding penguins?The researchers followed 50 already-banded adult penguins and 50 without bands for 10 years, tracking them with under-the-skin transponders. Thirty-six percent of the non-banded seabirds survived for 10 years, compared with only 20 percent of the band-wearing birds.

Penguins live about 20 years. King penguins - among the largest penguins at three feet tall - can live even longer, Le Maho said.

The no-band penguins had 80 chicks, while the banded seabirds produced 47 chicks, a 41 percent drop.

Penguin researchers have long debated the use of bands. The bands weigh just under an ounce and are a bit more than an inch wide, Saraux said.

One prominent American penguin researcher, P. Dee Boersma of the University of Washington, has been banding other kinds of penguins for 28 years and will continue.

"Their study shows that the bands they used on King penguins were a problem," Boersma, who studies Magellenic penguins, wrote by e-mail. "You don't want to say all flipper bands are terrible because the evidence is not there."

Boersma said the difference in species matters. She pointed to a 14-year study she did that showed that male Magellenic penguins with two bands survived the same as unbanded penguins, but that study did show that double-banded females had a lower survival rate.

Le Maho said he sees no reason why bands would harm some penguin species but not others.

Another expert, who wasn't part of the French study, said he found the case against banding convincing. Norman Ratcliffe of the British Antarctic Survey, which no longer uses bands, said it "augments a growing body of evidence" that bands harm the penguins and may bias the studies.

There is an alternative to the metal bands, Ratcliffe and the French researchers said. That's using transponder tags that are injected under the penguin's skin and send radio signals to buried antennas, much like pets with radio chips embedded in them.

Source: Philly.com Health News , By Seth Borenstein "Associated Press"