Birds will tuck a leg up under their fluffed plumes to conserve energy while at rest. I've overheard many bird watchers point out a one-legged bird, only to be surprised when the second leg miraculously appeared. Sunday night we walked on Fort Myers Beach and watched a Willet dart back and forth with the inhalation and exhalation of sea foam. Clearly this one has both legs.
Further down the beach we spotted another Willet behaving rather strangely.
It had only one leg. The other leg could have been bitten off. Maybe it was tangled in monofilament fishing line, restricting blood flow and causing it to fall off. Maybe it was born without it. It did have a small stump which was noticeable as it hopped around.
The bird did not feel sorry for itself. It asked for no favors. It simply hopped about in the surf in a very un-Willet like gait, feeding on invertebrates and such. We watched it feed for several minutes, impressed by its determination, balance and grace. It occurs to me that you can do anything when you must. Survival is harsh and beautiful all at once.