Flamingos are found on all the world's continents, except Australia. The unique species of wading bird has long being a source of fascination to humans, with their pink colored feathers and ability to stand on one leg.

In fact, it is this ability to stand and even sleep on only one leg that has long puzzled scientists for years. Guesses behind why they can sleep on one leg have ranged from reducing muscle fatigue to managing body temperature. Now, a pair of Atlanta-based biologists have found out how and published their study in the scientific journal 'Biology Letters.'

Finding a way to study the Flamingo

Biologists Lena Ting from Emory University and Young Hui-Chang from Georgia Tech started their study at the Atlanta Zoo in Georgia but were denied access to study their flamingos.

They then put out a call to nearby zoos, and the Birmingham Zoo in Alabama responded to their request.

The zoo had just euthanized two flamingos, so they sent them to the researchers to use in their study. When the pair of biologists started to examine the flamingos, Chang held one of them up by its leg. The leg immediately snapped into place, and the bird was able to stand up perfectly fine on a table, just like it would if it were asleep. Even more interesting was that the flamingo corpse could not stand up on two legs, only on one.

How flamingos can stand on one leg

It turns out that flamingos do not use active muscle force to balance on one leg as a human would do. Instead, the unique skeletal and muscular systems of the bird allow gravity to do all the work in keeping the bird steadied on one leg.

Just like humans, flamingos have a knee and ankle. Their ankle is in the bent backward in the middle of their feet, while the knee is hidden under the bird's feathers in the fatter part of its body.

When the bird is ready to go to sleep, it lifts up one leg and naturally moves its body, so its single foot is not on its hip.

Pulling that other leg up, which the flamingo rests on, forces the bird's knee to bend. After this, all the bird's joints are snapped into place, and it can just stay balanced, go to sleep and let gravity take care of the rest.

Why this study has answered why flamingos stand on one leg, it still leaves biologists wondering why they do. There still need to be an in-depth examination as to when and where the birds stand on one leg. The study is still a significant step forward in understanding more about this unique birds.