Treadmill Study Finds Fat King Penguins Are Less Steady on Their Feet

Posted on February 25, 2016

King Penguin on a treadmill

Scientists used a treadmill to study the stride of king penguins. In the study fat and slim king penguins were placed on a treadmill. Ten captured penguins were assessed as they walked on the treadmill for 10 minutes at the same speed of 1.4 km/h.

The researchers found no evidence for a difference in dynamic body acceleration or stride frequency between the two body masses. However, they did find evidence that slimmer penguins exhibited a decrease in waddling amplitude. The scientists say the study provides evidence that fat king penguins are less stable walkers.

The Guardian reports that some weight gain is essential for penguins as they need a fast reserve to survive the time period when they are caring for eggs.

The penguins did not always cooperate with the researchers. Astrid Willener, lead author of the study from the University of Roehampton, London, told the Guardian, "Once the speed is set, the penguin usually can walk fluently. But an individual that is not able to walk straight away on a treadmill is difficult to train. Sometimes the penguins were lazy and 'water-skied' on the treadmill by leaning their back on the back wall of the treadmill. That is obviously not good for the data collection."

Willener also says, "The weight gain is an adaptive mechanism for them to survive their fast while reproducing and taking care of the egg. But it is a trade-off between putting on weight to fast longer, in case there is a delay in finding a penguin partner to mate with, and still being able to walk, because if they can't walk steady, they fall and will be spotted and eaten alive by predators. However, pedestrian locomotion is only their secondary locomotion mode."

Here is a video of the penguins on the treadmill. Take a look:

A research paper on the study was published here in the journal, PLOS One.

Photo: Astrid Willener

More from Science Space & Robots