Why Do Herons Stand on One Leg?

Great blue Heron one leg -2©Kim Smith 2013Great Blue Heron at Good Harbor Beach ~ Click to view larger

There are several theories as to why birds, especially large wading birds such as herons and flamingoes, stand on one leg, or “unipedal resting” as scientist like to refer to the trait. The seemingly most convincing and best-proved theory is that birds stand on one leg to conserve body heat. It is shown that birds stand on one leg more often when wading, which again points to the thermoregulation hypothesis because water draws away more body  heat.

Great Blue Heon one leg Good Harbor beach ©Kim Smith 2013 copyGreat Blue Heron (Ardea herodias)

Standing on one leg is not necessarily a sleeping and resting habit. I have filmed Great Blue Herons and Snowy Egrets meticulously preening while standing on one leg. The characteristic is not limited to large wading birds; species with shorter legs, including ducks and swans, also stand on one leg. Another popular theory suggests that wading birds stand on one leg to look less suspicious to aquatic prey.

wp4768443cCenter of gravity and line of gravity

wp0e750516Goose standing on one leg

To read more about avian sensory physiology, visit the website of Professor Dr. Reinhold Necker. Additional images courtesy Professor Necker’s website.

11 comments

Leaving a comment rewards the author of this post- add to the discussion here-

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s