Flamingos live on every continent except Australia and Antarctica, and are a wonderful sighting, flocking together in groups with their bright pink feathers, elongated necks and unique upside-down eating style. There’s one particular question about flamingo’s behaviour that has stumped scientists for some time, namely, why do flamingos stand on one leg?
When resting, flamingos are often – but not always – seen standing on just one leg, with the other raised up into its feathers. Most large wading birds are able to stand on one leg, and flamingos are one of the largest wading birds around. Given their size it’s an impressive ability, particularly considering flamingos’ weight is oriented horizontally rather than vertically, and their legs are longer than their bodies.
Scientists haven’t found a gene for standing on one leg, but believe it’s a learned behavior. passed down from a mother to her offspring.
A flamingo chick practices standing on one leg.
Before we get started on the why flamingos stand on one leg, let’s look at the how:
Standing on one leg is a challenging yoga posture for humans – to maintain our balance we need to continually use our muscles to make adjustments to our posture.
Flamingo legs are built very differently from human legs, however, and when flamingos raise one leg two things happen:
- Their ankle joint snaps shut to lock the foot-to-leg joint in place.
- Their standing leg inclines so that the foot moves from being directly under their hip to being directly under the center of the body.
- The center of mass moves to just in front of the flamingo’s (hidden) knee, so its body weight naturally pulls the hip and knee forward.
These things, combined with gravity’s pull and the shape of flamingo’s leg bones, keeps all the joints in place and allows them to stand on one leg for hours on end with no need for any muscular activity.
Flamingos can happily sleep standing on one leg, and, incredibly, they can even stay balanced on one leg when they’re dead. It’s possible to pose a flamingo cadaver on one leg, and leave it there, still standing!
Understanding how flamingos stand on one leg doesn’t tell us why flamingos stand on one leg. Let’s look at those theories now:
8 theories for why flamingos stand on one leg
There’s no universally accepted reason why flamingos stand on one leg. Rather, there are a number of different theories, some more likely to be correct than others. Let’s look through the theories, the reasoning behind each theory, and the likelihood of each theory being correct:
It’s a way to conserve heat
Legs and feet are a significant source of heat loss in birds, so holding one leg closer to the body could help them conserve heat.
The idea that birds living in tropical habitats need to conserve body heat may seem counter-intuitive, but flamingos spend most of their time in the water, which can lower the temperature of warm-blooded animals fairly quickly. One estimate puts the heat loss of a flamingo standing on two legs rather than one leg at between 140% and 170% more.
This theory was put to the test in a 2009 study at the Philadelphia Zoo, where the team tracked the temperature and weather conditions when the flamingos were resting. They found that when the weather was warmer, more birds would stand on two feet, while in cooler weather, more birds stood on one leg.
These results suggest that thermoregulation is a key reason behind the classic one-legged flamingo stance, though doesn’t rule out other theories also having some benefit.
Likelihood of being correct 8/10
It’s a natural reflex to stop them from falling over when sleeping
This theory suggests that flamingos share a behaviour seen in ducks, whales, and dolphins, and are able to shut down half their brain when they sleep.
As flamingos go into this half-awake state, a natural reflex kicks in, and the leg controlled by the side of the brain that’s awake stays on the ground to maintain balance. The other leg gets pulled up to rest – lifted towards the body as if it were gently lowering the body onto the ground.
Standing on one leg would keep the flamingo from falling over – and potentially drowning – because, as we’ve seen, flamingos have a build that actually gives them better balance when using one leg rather than two.
Likelihood of being correct 8/10
It’s more comfortable/reduces muscle fatigue
When standing on two legs, both legs are perfectly vertical. Because of the way a flamingo’s legs are built their leg joints are more unstable when both feet are flat on the ground.
Counter-intuitively, flamingos are actually more stable on one leg than on two. The act of balancing on one leg requires less muscular effort and allows the birds to sway less, according to a Royal Society report. It’s not a giant leap to consider that a flamingo would therefore be more comfortable standing for long periods – and sleeping – on one leg rather than two.
Given that flamingo cadavers can remain upright on one leg, but not two, there could well be something in this theory.
Likelihood of being correct 8/10
It helps keep their feet dry
Perhaps flamingos stand on one leg to dry their other foot off. As flamingos alternate which foot they’re standing on, this theory does seem possible, but it doesn’t seem too likely that a wading bird doesn’t like getting its feet wet.
Likelihood of being correct 3/10
It’s a way to better camouflage themselves
The water habitats where flamingos feed have plenty of long, thin objects in them – like reeds and small trees. A flamingo on one leg could some sort of thin plant life leading to a larger top when seen from the water, where a flamingo’s prey lives.
It’s certainly a possibility, but unlikely given flamingo’s prey – algae, shrimp, molluscs, and aquatic plants are not particularly sight-driven, on the lookout for hungry birds. (See some other – better – animal camouflage examples.
Likelihood of being correct 3/10
It saves energy
Could it be true that a one-legged posture helps flamingos to conserve energy?
If saving energy was the main benefit of their one-legged stance we would reasonably expect flamingos to use this resting position constantly. Research has shown that flamingos are more likely to do so on cooler days, however, or while in the water, seemingly ruling out this theory.
Likelihood of being correct 2/10
It minimizes contact with parasites
Flamingos hang out in some pretty harsh water conditions, with plenty of parasites and fungi. Standing on only one leg would allow them to minimize the amount of contact they have with any parasites and fungi present in the water they’re wading in.
This theory would have weight if flamingos spent all of their time in the water on one leg. As it is, their stance on one leg vs two seems to be driven by the weather rather than the type of quality of water.
Likelihood of being correct 2/10
It helps flamingos flee predators more quickly
Researchers have put this theory to the test by timing how long it takes flamingos to start moving from both one-footed and two-footed resting positions. If this theory was correct, you would expect the birds to take their first steps faster when starting on one leg., but the research team found that the birds made a faster start when they had been standing on both legs, clearly ruling out this theory.
Likelihood of being correct 0/10
So which theory is correct?
At the moment we simply don’t know for sure, but the heat conservation theory seems to be at least part of the answer. Likely the true reason is a combination of more than one of the above theories. We’ll keep this post updated as the science progresses, so be sure to check back! In the meantime, here are a couple of funnies relating to ‘why do flamingos stand on one leg’:
Watch a fun alternative take on why flamingos stand on one leg
One legged flamingo jokes
Q: Why do flamingos stand on one leg?
A: If they lifted the other leg they’d fall over.
Q:Why did the young flamingos get in trouble?
A: Their father finally put his foot down.
And that’s the lot for this examination of why flamingos stand on one leg. What do you think is the most likely theory? Or do you have any other theories of your own? We’d love to hear from you in the comments section below!
