In an earlier post on the Crested Goshawk (Accipiter trivirgatus peninsulae) (left), we provided an image of the raptor standing on one leg. This raised questions on why birds stand on one leg and whether it is a common practice.
“Why do birds stand on one leg?” has been a recurring question among birdwatchers for a very long time.
According to Evans & Heiser (2004), birds tuck one foot close to their bellies to keep warm on a chilly day. After all, the legs of most birds are not covered with feathers and they have been shown to be important sites of heat exchange (Steen & Steen, 1965). Other ways of conserving heat include tucking the bill into the feathers of the shoulder, fluffing their feathers to increase the air space and roosting close together.
However, the fact that birds also stand on one leg under warm conditions means that thermoregulation is not the only function.
And while standing on one leg, these birds continue to rest, preen or sleep.
Check out our earlier post on the Hooded Pitta (Pitta sordida) standing on one leg HERE.
References:
1. Evans, H. E. & J. B. Heiser, 2004. What’s inside: Anatomy and physiology. In: Podulka, S., R. W. Rohrbaugh Jr & R. Bonney (eds.), Handbook of bird biology. The Cornell Lab of Ornithology, Ithaca, NY. Pp. 4.1-4.162.
2. Steen I & J. B. Steen, 1965. The importance of the legs in the thermoregulation of birds. Acta physiol. scand. 63: 285-291.
8 responses
This may be of interest:
http://news.bbc.co.uk/earth/hi/earth_news/newsid_8197000/8197932.stm
Thanks Aydin.
agreed that sometimes it seemed warm but the birds still stand with one leg, for example, the male Crested Goshawk in my garden is usually seen resting on one leg only, and at many occasion, its quite a hot day….
I’d like to know why my birds do this even in the summer months, when it’s extremely warm out. We don’t’ even have a/c!
We know something about this phenomenon, or we think we know. But we do not know everything.
I think they raise one leg because if they raised both legs, they’d fall flat on their bellies 🙂
I’ve observed Mr robin on one leg most of the day between catching insects and taking them to its young, it’s been a warm day and reading this article I’ve come to the conclusion he must be exhausted and simply resting when he can, he really has been busy. Wonderful to watch.