Newly hatched Emperor penguins suffer under the conditions of bullying and harassment. A detailed study has recently revealed this.
The mature Emperor penguins are very aggressive, forcing the chicks to huddle tightly together in groups to survive. The study, published in the journal Animal Behavior, found that the unfortunate chicks on the edges of these crowded groups are easily bullied or even eaten, to the extent that they can never truly sleep.
“Penguins sleep by intermittently closing their eyes for short periods, like a kind of “peeking” during their vigilant sleep“, explained Michel Gauthier-Clerc, one of the study’s authors. “Despite this drowsy state, they still manage to be aware of their surroundings“.
Gauthier-Clerc, from the Tour du Valat Biological Station in Arles, France, and his colleagues studied over 16,000 Emperor penguins Aptenodytes patagonicus living on Possession Island, Antarctica. Chicks abandoned by one or both parents are often attacked or kicked by other adult penguins. They frequently run towards other chicks until they form a tightly packed group.
The chicks strive to secure a position at the center of this dense group. The smaller, weaker ones are pushed to the edges, where they are often attacked and preyed upon by brown skuas and kelp gulls. While the lucky ones in the warm and secure center sleep soundly, those on the periphery can only rest briefly during their highly vigilant sleep cycles.
Gauthier-Clerc explained that sleeping is an energy-saving process essential for all vertebrates, including humans. Although taking a short nap is better than not sleeping at all, the bullied chicks on the edges still suffer more.
“We believe that chicks on the periphery save less energy due to the cold and lack of sleep. They are not sheltered from the cold wind, are more vulnerable to predators, and sleep less“. He also pointed out that chicks must endure this situation, with no food, throughout the winter until their parents return at the end of the season with supplies.
T.An (according to Discovery)
