Why can birds sleep standing up?



Birds are bipedal creatures like humans, but unlike humans, birds have the ability to 'sleep standing up in a stable position.' A research team from the French National Center for Scientific Research analyzed the body structure of birds and found that the body of birds forms a 'tensegrity structure,' allowing them to maintain a stable position without using energy.

An upright life, the postural stability of birds: a tensegrity system | Journal of The Royal Society Interface

https://royalsocietypublishing.org/doi/full/10.1098/rsif.2023.0433

Why birds do not fall while sleeping | CNRS News
https://news.cnrs.fr/articles/why-birds-do-not-fall-while-sleeping

Birds and humans are bipedal creatures, but the difference is that birds stand in a bent position while humans stand upright. When birds stand, they are standing on their tiptoes like a human, which is an unstable and energy-intensive position, but birds can stand for long periods of time in the wind and rain, and can even sleep in that position.



The research team used a simplified model of the body structure of birds to analyze why they can maintain a stable posture. As a result, it was found that birds' bones, muscles, and ligaments form a 'tensegrity structure.' A tensegrity structure is a 'stable structure that appears unstable' formed by a combination of 'hard materials' and 'pulling materials.' The following video makes it easy to understand what a tensegrity structure is.

[Crafts] Is this floating in the air?! [How to make a tensegrity structure] How to make a tensegrity structure - YouTube


Below is a model of the body structure of birds. The tensegrity structure is formed by the tendons that run behind the knees and the ligaments around the knees. The tensegrity structure makes it possible to maintain a stable posture without losing physical strength even when wind or shaking at the feet occurs. In addition, since you can maintain your posture without thinking, you can sleep while standing.



According to the research team, the tensegrity structures of birds could potentially be used in robotics.

in Science,   Creature,   Video, Posted by log1o_hf