Flamingos are well-known for standing on one leg - but, until now, no-one has been entirely sure why they do it.

One theory was that they did it to help regulate their temperature, as putting both down when stood in water would draw away more body heat.

However, researchers now believe they have found an alternative answer. According to a new study published in the Royal Society journal Biology Letters, it actually requires less effort for a flamingo to stand on one leg than it does on two.

Professor Young-Hui Chang from the Georgia Institute of Technology and Lena H Ting of Emory University conducted a series of experiments using the bodies of dead flamingos - and found it was easier to stand them up on one leg rather than two.