Researchers from the US have uncovered that the iconic bird has a unique mechanism in their legs that fixes together when straight meaning they don’t have to expend any muscular energy.
Dr Lena H Ting of Emory University, Atlanta and Professor Young-Hui Chang of Georgia Institute of Technology confirmed the theory when dissecting flamingo corpses donated from Birmingham Zoo. During the first dissection, they found no trace of locking joints, the discovery of the mechanism came after Chang picked the bird up by its leg and the body remained upright, Chang explains:
Image: Greater Flamingo, Phoenicopterus rube, shutterstock
We demonstrated that flamingo cadavers could passively support body weight on one leg without any muscle activity while adopting a stable, unchanging, joint posture resembling that seen in live flamingos.
Surprisingly, they could not stand deceased flamingo upright on two legs, indicating that the flamingo must use more muscles to stand on two legs than one. Chang and Ting explained the new evidence:
By contrast, the cadaveric flamingo could not be stably held in a two-legged pose, suggesting a greater necessity for active muscle force to stabilise two-legged versus one-legged postures.
They tested this theory on live flamingos using something called a force-plate. The researchers discovered that when flamingos are less active or asleep they will sway less on one leg than two. Seemingly indicating that flamingos rely on a passive mechanism for support, not a muscular or active joint. The bird’s weight forces the joint to lock. This can only be achieved when the standing leg is placed directly underneath the flamingo's body. The bird can effectively support itself without any conscious effort. This is the first discovery of such a mechanism.
Our results suggest that flamingos engage a passively engaged gravitational stay apparatus (proximally located) for weight support during one-legged standing
More research will need to be conducted to better understand the mechanism and how the flamingo uses it. Further studies could also shed light on birds such as the heron and the stork who use their legs in a similar fashion.