January 13, 2011

Bands Used For Penguin Research Drop Survival Rate

According to new research published Wednesday in the journal Nature, 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.

The study's authors wrote that the theory is that the metal bands increase drag on the penguins when they swim, which makes them have to work harder.

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

Le Maho and colleague Claire Saraux said that studies that use banded penguins may be inaccurate, mixing up other changes in penguin life with the effects from banding.

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

"There is an ethical question: should we continue with banding penguins?" Le Maho asked. The very act of studying the birds is harming them, he told the Associated Press (AP).

The team 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 to 20 percent of the banded birds.

Le Maho said that penguins live about 20 years and King penguins can live even longer.

The non-banded penguins had 80 chicks, while the banded penguins produced 47 chicks.

The penguins were studied on a French island in the Indian Ocean between Africa and Antarctica.

Saraux said that the bands weigh just under an ounce and are a bit more than an inch wide.

P. Dee Boersma of the University of Washington and a prominent American penguin researcher has been banding another kind of penguin for 28 years.

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

Boersma told AP that the type of species makes a big difference.  She used a 14-year studyas an example to show that male Magellenic penguins with two bands survived the same as unbanded penguins.  However, that study did show that double-banded females did not survive as long.

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

Norman Ratcliffe of the British Antarctic Survey, who was not a part of the French study, told AP that he found the case against banding convincing.  He said it "augments a growing body of evidence" that bands harm the penguins and may bias the studies.

Ratcliffe and the French researchers said that an alternative to the metal bands would be to use transponder tags that are injected under the penguin's skin and send radio signals to buried antennas.

Saraux wrote penguins spend more time in the water than on land, and the transponder does not affect the penguin's swimming.  However, Le Maho said this technique is more expensive and has other drawbacks.


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