Banded penguins suffer

Trying to tell one penguin apart from another can be quite difficult – the tuxedoed birds tend to look very similar – so scientists developed a method of banding their flippers, a move which may have done more harm than good.

A ten-year monitoring project has revealed that the bands – a metal ID strip on the narrow part of the flipper near the shoulder – reduce penguin survival and success at raising families. On an Antarctic island, king penguins banded in this way had 41% fewer chicks and a 44% lower survival rate over the ten years.

The study looked at 100 electronically monitored king penguins – 50 of whom also carried flipper bands.  

Young penguin chicks at the breeding site – who need to build up reserves to survive their first winter – only eat what a parent comes home with food collected hundreds of kilometres away. The research showed that flipper-banded penguins averaged 12.7 days away from home on foraging trips instead of 11.6 days.

“One day or two days is a huge difference,” says ecologist and co-author Claire Saraux from the University of Strasbourg.

Scientists believe that the flipper bands may be increasing drag on penguins during swimming and in a swimming test in a tank an Adélie penguin wearing a band used 24% more energy than an unbanded penguin.

“From an ethical point of view, I think we can’t continue to band,” said Saraux.

The researchers also found that environmental conditions affected banded birds more severely than their unbanded counterparts and that the banded birds had a greater tendency to arrive late at the breeding grounds.