Study: Penguins take up to 10,000 short naps a day
The almost eight million breeding pairs of the penguin with the scientific name Pygoscelis antarctica live in the Antarctic and on some islands in the South Atlantic. When breeding, the female and male take turns. Alone on the nest, they must constantly protect their eggs from birds of prey, the brown skuas. In addition, the parent birds have to defend their nests against other penguins trying to steal nest material.
This constant tension is the reason for the unusual sleeping behavior of the chinstrap penguin: during breeding, the parent birds accumulate large amounts of sleep through thousands of microsleep phases, as the researchers have discovered. They usually do not nod off for more than four seconds at a time, but still get up to twelve hours of sleep through over 600 sleep phases per hour - a total of over 10,000 per day.
In December 2019, the research team led by Paul-Antoine Libourel from the Neuroscience Research Center in Lyon recorded the behaviour and brain activity of wild chinstrap penguins breeding in a colony on King George Island in the Antarctic. To measure their brain activity, they equipped 14 birds with specially designed data loggers. This was supplemented by video recordings and direct observations.
These activities of the birds were recorded for eleven days on land and at sea, where the penguins dived to a depth of 200 meters. The researchers then investigated how nesting at the edge of the colony, where the penguins are exposed to birds of prey, affects penguin sleep compared to the center of the colony.
The surprising result: the birds at the edge of the colony sleep ten percent more and one second longer than the birds in the center of the colony. Disturbances and aggression from other penguins within the colony therefore have a greater influence on sleep than the danger from predators.
The researchers also showed in the study that penguins can also sleep swimming at sea. Overall, they slept significantly shorter at sea than on land. After returning to land, some of the missed sleep was made up for, albeit only in phases lasting an average of four seconds.
Lesen Sie auch:
- Despite the threats from birds of prey and other penguins, the chinstrap penguins, a species numbering almost eight million breeding pairs, manage to take up to 10,000 short naps a day in the Antarctic and some South Atlantic islands.
- This unusual sleeping pattern is a result of the constant tension during breeding, where parent penguins can accumulate large amounts of sleep through thousands of microsleep phases.
- A study led by Paul-Antoine Libourel from the Neuroscience Research Center in Lyon observed and recorded the behavior and brain activity of wild chinstrap penguins in Antarctica, equipping 14 birds with data loggers to measure their brain activity.
- The birds at the edge of the colony, exposed to predators and aggression from other penguins, slept ten percent more and one second longer than those in the center, suggesting that in-colony disturbances have a greater impact on penguin sleep.
- Remarkably, the study also showed that penguins could sleep while swimming at sea, although they slept significantly less there compared to land.
- The Max Planck Institute for Ornithology in Germany and the French National Centre for Scientific Research also participated in this groundbreaking study, which was published in the scientific journal Current Biology.
- Surprisingly, this study's findings contradict previous beliefs that marine birds, including penguins, only sleep on land or while swimming at a depth, suggesting new insights into the physiology of bird sleep.
- As the researchers continue their study in South Korea, they hope to uncover more about the fascinating topic of penguin sleep and the role it plays in their survival in the harsh environments of Antarctica and the South Atlantic.
Source: www.stern.de
