Penguins living in the South Pole appear to benefit if less ice floats on the water. In periods with less ice in Antarctica, the birds seem to be able to eat better. Japanese scientists write this in the journal Science Advances.
Biologists have been researching Adelie penguins for a long time. In addition, they noticed that penguin populations grow very much in periods with little sea ice. In addition, the chicks grow faster and the adult birds have more body mass. In times of ice at sea, breeding periods are problematic.
It was unknown for a long time why this was the case. Until Japanese scientists decided to provide sensors to 175 penguins. Those sensors included speedometers, cameras and GPS systems. This allowed the behavior of the birds to be accurately measured.
The research shows that little sea ice leads to population growth, because the birds have more space to find food in the water. In periods with a lot of sea ice, the birds have to waddle around and look for a break in the ice to dive in.
When there is less ice on the water, the penguins are free to dive where they want. They then have much more space to find food and they also have to compete less with others for food.
Less ice also means more food
Finally, penguins eat krill, a shrimp-like animal that feeds on plankton. When there is less ice on the water, more sunlight enters the water, which in turn increases plankton growth. Then the krill can eat more and the penguin in turn also has more krill to feast on.
However, the researchers add that Adélie penguins live in mainland Antarctica. Penguin species that live on islands near the South Pole seem to thrive less with less sea ice. Why this and the difference between the two species remains to be seen in subsequent research.
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