Penguins On A Treadmill: Analyse Depicts Fat Ones Fall Over More Often Than Slim Ones
Experiment discovered the heavier monarch penguins from Antarctica were not as good at waddling, but the extra weight helped them survive fasting while breeding
Fat king penguins are unsteady on their feet while waddling compared to their slimmer equivalents, but carrying a little bit of extra weight comes with an important advantage when it comes to reproduction, biomechanics researchers say.
A research team led by Astrid Willener from the University of Londons department of life sciences travelled to the subantarctic region of Antarctica to research the monarch penguin, which can grow up to 1m tall and up to 16 kg, constructing it the second largest species of penguin behind the emperor.
Ten male king penguins who were in courtship and who weighed more than 12 kg were captured near the shoreline at the edge of a colony. The penguins, which are serial monogamists, have the longest breeding cycle of all the penguin species 14 to 16 months and create merely one chick per cycle. Weight gain is essential in courtship so that the penguins have enough fat reserve to survive their fast while taking care of their eggs.
However, being too fat stimulate them least stable and thus easily spotted and eaten by predators, Willener told. So understanding the biomechanics of how penguins deal with strolling with an additional one-quarter of their usual weight, while still being quiet stable, is very interesting.
The researchers maintained the penguins for 14 days and fasted them during this time, and tested them for their ability to walk on a treadmill at a speed of 1.4 km/ h before and after their weight loss. Fasting for periods of up to one month is normal for monarch penguins, and the researchers checked the critical body mass of the birds to be sure that “theyre not” losing body mass too fast. They also maintained the penguins in a pen next to their colony during the study.
However, there were difficulties in get some of the penguins to cooperate, Willener told, with some of the larger someones trying to defraud the system.
A good sum of the individuals were able to walk on a treadmill straight away, she told.
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.
The penguins received two training sessions of 10 minutes to get used to walking on the treadmill. The posture( leaning and waddling) of the penguins while strolling was then determined by the researchers. To quantify the waddling, the amplitude of peak left and right leaning was calculated.
They found that although the penguins waddled with more agility at a lower weight, they had nonetheless accommodated well to be able to handle waddling while heavier, even if “theyre not” as efficient and least stable.
Waddling amplitude, leaning amplitude and leaning slant all remained fairly constant across the two body mass, the study, published in the online science journal PLoS One, discovered.
However, some differences were uncovered; in particular there was good evidence that variability in the leaning slant and leaning amplitude, and some evidence that the waddling amplitude, were lower when the birds were lighter. These outcomes indicate that heavier king penguins have a higher frontal and sagittal instability; they are less stable walkers than when they are lighter.
But with swimming the primary method of travel for the birds, being agile in the water was more important that a quick and graceful gait, Willener said.
The weight gain is an adaptive mechanism for them to survive their fast while reproducing and taking care of the egg, she told.
But it is a trade-off between putting on weight to fast longer, in case there is a delay in detecting a penguin partner to mate with, and still being able to walk, because if they cant stroll steady, they fall and will be spotted and eaten alive by predators. However, pedestrian locomotion is merely their secondary locomotion mode.
Willener hopes the findings will help in efforts to better understand, and protect the species. While king penguin numbers are not threatened, they have been in the past.
The is connected with gait and energy expenditure can help to improve penguin protection, she told. The energy expended during their stroll, particularly when emphasized and responding to predators, may affect their ability to fast and protect their chicks.
* Note: The video has been sped-up, and so the speed seems faster than the reality. No penguins were made to fall over on the treadmill . Read more: www.theguardian.com
Penguins On A Treadmill: Analyse Depicts Fat Ones Fall Over More Often Than Slim Ones
Penguins On A Treadmill: Analyse Depicts Fat Ones Fall Over More Often Than Slim Ones
Penguins On A Treadmill: Analyse Depicts Fat Ones Fall Over More Often Than Slim Ones
Penguins On A Treadmill: Analyse Depicts Fat Ones Fall Over More Often Than Slim Ones
Penguins On A Treadmill: Analyse Depicts Fat Ones Fall Over More Often Than Slim Ones