Penguins are far good swimmers than they are pedestrian , but sometimes they have to trek immense distance on land by coggle on their short leg . Now , researcher studying king penguin walking on treadmills break that heftier male ( fresh from their eating visit at sea ) are less steady on their feet . The findings are put out inPLOS ONEthis week .
Rex penguin ( Aptenodytes patagonicus ) spend a foresighted time trail prey in the sea , and after they return ashore , they often have to journey across large swathes of land to attain their breeding colony – all while carrying a operose accretion of fatness as well as food in their stomach to purvey their chicks . Once they reach their destination , they typically have to fast for up to a month , relying only on their get-up-and-go store , and they end up lose about a quartern of their body mass .
To see if lifelike variation in torso mass impact the penguin ’s walk gait , a squad top byAstrid Willenerfrom the University of Roehampton bewitch 10 manly king penguins during the austral summer from a colony at Baie du Marin on Possession Island in the Crozet Archipelago . They then trained the penguins to walk on a treadmill with an speedup data logger attached to the feathers on their back . The penguins walked for 10 - minute separation at a speed of 1.4 kilometers ( 0.9 miles ) an hr . The investigator collected datum for each penguin at two body masses : On the first mean solar day , the penguin weighed an average of 13.2 kilograms ( 29 pounds ) , and on day 14 of their fasting , they weighed 11 kilograms ( 24 Egyptian pound ) on average .
King penguins , the team encounter , do n’t exhibit major conflict in their walking biomechanics whether arduous or illumination – not with stride relative frequency nor body acceleration . There were , however , departure between skinny and fat penguins when it come to how much the body leans : When the penguin are slimmer , there ’s less variability in the leaning angle and amplitude . skinny birds also showed a decrease in waddling amplitude . When they gain weight , it becomes more difficult to control the larger heap and the impulse associated with it .
When the birds are heavy , their head-on fat accumulation seems to shift their middle of mass forward ( see image to the right hand ) . And this result in a less unchanging posture when they ’re just , which may cause them to fall forward during each step .
Check out a picture of one of the penguin walk on a tread-wheel above . Science Magazine
Image in the text : The theoretical change in the location of the sum of mass between a light ( left ) and heavy ( right ) Rex penguins in a standing posture . A.S.T. Willener et al . , 2016 PLOS ONE
