14 DAY TRIAL // It's a widely known fact that penguins are among the most cooperative animals when it comes to rearing their young ones. The males and females both share the responsibilities that come with having an offspring, and for this they have been often praised. But now, a new study has shown that this commitment lasts only to a certain extent. When they crippled one member of over 40 penguin couples, by attaching a Plexiglas box on their backs, scientists noticed that the partner did not take on any extra responsibilities from the impaired one, and did not attempt to help the other in any way.
“In Adelie penguins, when one mate was handicapped, no compensatory care was observed from the partner. As a consequence, handicapped individuals and offspring both supported the whole additional breeding cost of the handicap,” wrote experts from the Institut Pluridisciplinaire Hubert Curien in a paper detailing their study, published in the Tuesday edition of the respected journal Animal Behavior. They also explained that the boxes they had attached to the small animals were not designed to impede any of their daily activities, but rather to increase their drag during hunting and diving, which is essentially the largest handicap a penguin can have.
“According to previous studies, we could guess what the potential effects of the dummy devices would be on handicapped penguins, but not on their partner or their chicks,” explained in an e-mail animal ecologist Michael Beaulieu, who was one of the new paper's co-authors, quoted by Wired. During the course of the experiments, the team noticed that, while the affected partner tended to spend a lot more time at sea, collecting food for the youngsters, the other partners couldn't care less about their mates' plight, and went about their business as usual, without making any effort to help.
Beaulieu also said that penguins did not invest too much effort in a single mating season because they were long-loved birds, and too much attachment wouldn't make sense. “Short-lived birds have only a few breeding attempts during their lifetime while long-lived birds have a lot. As a result, short-lived birds are expected to give the maximum during one breeding season to increase the probability of survival of their current chicks. Consequently, when the investment of the partner decreases, short-lived birds are expected to compensate while long-lived birds are expected to keep a fixed level of parental investment,” he said.