The potential costs of flipper-bands to penguins
1. The published literature on the effects of flipper-bands on penguin ecology is reviewed. Six published studies show the following. 2. In Adélie Penguins Pygoscelis adeliae, flipper-bands directly damaged flippers, increased swimming costs by 24%, decreased survival in the first year after banding by 28%, and may have accelerated decline of a dwindling colony by 3%. 3. Adult return rates to colonies among flipper-banded Adélie, Chinstrap P. antarctica and Gentoo P. papua Penguins decreased by 8%, 12% and 25%, respectively, between single-and double-banded penguins. Juvenile return rates among Gentoo Penguins were reduced by 10.5%. Return rates to the colony among double-banded King Penguins Aptenodytes patagonicus were 31.3% and 6.7% lower than among single-banded birds in the first and second years after banding, respectively, and single flipper-banded birds showed annual survival rates 21.1% lower than those of birds fitted with subcutaneous transponders. 4. Among Royal Penguins Eudyptes schlegeli, there were no differences between chick growth, adult over-winter survival and fledging success between flipper-banded birds and birds fitted with transponders. 5. Adélie Penguin adult annual survival rates were lower among flipper-banded birds than among unbanded birds. 6. On the basis of dive profiles for Adélie Penguins, it is estimated that increased swimming costs of 5% reduce prey contact time by 10%, and of 24% reduce prey contact time by 48%. These estimated 'knock-on' or cumulative costs coupled with the survival and breeding costs shown by the majority of published field studies suggest that data collected on some flipper-banded populations are biased. 7. The advantages and disadvantages of an alternative long-term marking technique, subcutaneously implanted passively interrogated transponder tags, are discussed. Research projects currently testing transponders and flipper-bands worldwide are listed.