Legless shorebirds?

Well, not really. At Nickerson Beach yesterday, I noticed a lot of sanderlings and some semipalmated plovers hopping around one one leg. I found it rather disturbing until I spoke with a fellow birder later that day who told me that they do that because they get lazy and just stand and hop on one leg. I am new to observing shorebirds closely this year but I don't know how I missed seeing this on other trips to the beach! In any case, is there a scientific reason as to why they do this or are they simply lazy or giving their legs a break? I'm posting an image of a semipalmated plover getting ready to hop away from me in my car (this was taken in the parking lot at Nickerson where a lot of these and the sanderlings were roosting).

Nice observation Beth. I've seen this a lot but do not know if it is fully established why shorebirds/waders do this.

Image is Lesser Yellowlegs sandwiched between two Greater Yellowlegs cousins.

Theories anyone?

I have no idea but would guess it saves energy.

Perhaps. I could really see something similar being true in the winter when it's so cold the bird wants to save body heat by tucking one leg up into its body. I would think hopping around on one leg would use more energy than just walking from point A to B. They must have excellent balance because I expend a lot of energy when I try to stand on one leg for an extended amount of time. :D

Thanks for asking the question, Beth. I've wondered the same thing and I agree, hopping around on one leg is definitely more energy intensive for me!

Hello Beth.

I don't get much opportunity to contribute here as my wife has asserted that if she catches me spending anymore time at the computer than I already do, then she is going to with hold my pleasures! I don't understand what she means by this....I can only surmise that she plans to hide my copy of ABP II.

Anyhow, I am a consultant ornithologist based in northern Australia. Most of my career I have concentrated on bird behaviour, especially migratory shorebirds, having worked for The Great Barrier Reef Marine Park Authority, amongst other agencies. Thus I have a sliver of insight into these things.

It is true that by standing on one leg, the birds will reduce energy loss in the form of heat by both radiation & convection.
However they do this across a spectrum of climatic conditions.

Migratory shorebirds especially, concern themselves with maintaining their plumage in as perfect condition as possible, their lives depend on it. I could go into tomes of esoteric ramblings covering their dynamics so lets just leave it at that.

You may notice that they engage in such behaviour when they are usually in a dozy state. On face value, if the nod off & the wind changes, misdirectional pressures could damage their plumage.

However, you will notice that when on one leg they are able to pivot into optimal positions to prevent this occuring, akin to a windsock at an airstrip. They are even able to do this when asleep!

It is unsure what the mechanism for this is but the wind direction possibly stimulates the nerve endings surrounding the base of their filoplumes (those wispy plumes most easily seen on plucked poultry). Thus they can change direction by relex action. Filoplumes are also believed to transmit data re barometric pressure to their brains (possibly to an area called the hyperstriatum though this is currently conjecture) prior to migratory take off & during flight, so it would make sense.

Here in the South East Asian flyway we often also see birds standing on one legs, usually Lathams's Snipe, Whimbrel & Eastern Curlew that have had legs amputated by snares set for them by protein hungry Asian folk. Always a sad sight to behold.

Hope this has been of help mates....Oh God...here comes the wife!!!
Regards & keep safe,
Frank

Welcome Frank. Please come back any time you like, of course with the permission of She Who Must Be Obeyed!

I like the explanation that they stand on one leg to essentially turn in the wind. If they tend to turn such that they face the wind while sleeping on one leg, another hypothesis is that this gives them the ability to take off quickly in case a peregrine or other predator is coming down on them. What do you think about this anti-predator hypothesis?

Ahoy John
She is just pegging out the washing. So, quickly....

It is an interesting hypothesis & may hold some merit but I cant see it at face value.

I know we don't have wings but imagine yourself in some strange culture. You have been naughty & sentenced to have a tiger have at you, released from a cage right behind you. Would you rather have both pins on the ground & crouched like a sprinter or be teetering on one leg?
Even with wings you would have more thrust at take off by pushing down on two legs.

Incidentally, As a true kindred spirit You are always welcome at our home in Far North Queensland (where the birds are so plentiful, that they drip off the trees!). Plus will also notice that I am one of the rarest species on Earth, a scientist with a sense of humour.....Oh, there goes the back door!.........
Cheers chums
Frank

Hi Frank, thanks for that very interesting information. I still wonder, though, about them hopping around on one foot. It wouldn't affect their feathers but it must expend energy.

Not sure about the stuff with your wife but it sounds like she's got you behaving as best she can. :D

Avast Frank. Reasoning is as follows: shorebirds on migration have to rest so that they optimise their fat gain. If you have to rest, then at least face into the wind to reduce the chances of being caught by surprise and eaten. Roosting Semipalmated Sandpipers here definitely face into the wind when they are roosting. Question is, does the one-legged stance help in this regard?

My life's dream is to visit Australia. As a kid in UK I did a huge project on the country and even wrote Robert Menzies and received a nice letter back from his private secretary-- I still have it, and a signed autograph. I was smitten! I've been to South America many times but never to your great country. Cheers for the invite mate. I may just make it one day!

G'day again John.

I knew it, I thought you may be a pommie ex pat, ah the British, the most bird caring folk on the planet.
And at least you have experienced, albeit remotely, the great Aussie friendliness that we so proudly espouse.

Hi Beth.
The hopping is not a strategy but incidental to the one legged stance.
If you watch them closely, shorebirds will only employ X number of hops before finally putting the other leg down.

The energy difference (ie muscular, heating, electrical & plumbing) expended between a few hops & that required for replacing the 2 legged stance, readjusting position & balance before re adjusting again is initially more efficient albeit still requiring some energy loss. You might say that it is the lesser of two weevils.

To confirm this however would require cutting edge, high tech equipment plus the kind of protracted & tedious research that I eschewed long ago.
Notwithstanding, I'm sure there is some bright young thing out there that will one day provide the definitive proof.

Cheers chaps
Frank

Actually Frank, I'm Canuck, but grew up in Blighty until 14 yo. Can't underestimate the effect of this though. I blame bluebells and cuckoos in the spring.