A King penguin with a tracking band on its flipper walks among other adults and juveniles on the sub-antarctic island of Crozet. A new study now shows these bands have hugely detrimental impact.
Credit: AP Photo/Nature, Benot Gineste
PARIS: Tagging penguins with flipper bands harms their chances of survival and breeding, a finding which raises doubts over studies that use these birds as telltales for climate change, biologists said.
The metal bands, looped tightly around the top of the flipper where it meets the body, have long been used as a low-cost visual aid by researchers to identify individual penguins when they waddle ashore. Foot tags are not used because of the penguin's anatomical shape.
But, says the new study, the seemingly harmless bands affect the penguin's swimming performance, causing it to waste more energy in foraging for food, sometimes with life-threatening consequences.
Publishing in the journal Nature, French and Norwegian scientists reported that they took 100 king penguins (Aptenodytes patagonicus), selected at random on Possession Island on the Crozet archipelago, a sub-Antarctic group in the southern Indian ocean.
39% fewer chicks from tagged birds
All were tagged with a minute, electronic transponder that was implanted under the skin, which can only be read by using specialist equipment placed close to the bird. Fifty of the 100 birds were additionally given a flipper band. The team then recorded sightings of the group over the next 10 years.
Banded birds were 16% likelier to die than non-banded counterparts, and had 39% fewer chicks, they report.
"The picture is unambiguous," researcher Yvon Le Maho said. "Among banded penguins, the least-fit individuals died out in the first five years of the study, which left super-athletic birds. "In the remaining five years, the mortality rate between the two groups was the same, but the reproductive success of banded penguins was 39% lower on average."
Loss of power and lateness observed
Le Maho said he had warned many years ago against banding penguins on ethical grounds but was sidelined. Opponents argued that the birds were not affected by the practice or got used to the tag after a year or so. The latest findings, though, are unequivocal, he said.
They add to small-scale studies on captive Adelie penguins that suggest these birds - which beat their flippers about three times a second when swimming - lose up to 24% of their power when banded.
Le Maho said that banded penguins in his study arrived much later (16 days later on average) at breeding grounds compared with non-banded counterparts. Late arrival is a known factor for poor breeding success, for chicks that are born later are nurtured in harsher weather and there are more predators around to grab them.
Heisenberg's Uncertainty
Heisenberg's Uncertainty Principle works for penguins, too. Whod've thunk?
Heisenberg's what?
The comment about Heisenberg's Uncertainty shows gross misunderstanding of the principal of uncertainty, and further makes no sense even from the ignorant viewpoint it is implied from.