…stand on one leg. Every yoga class that I have attended has always included the dreaded (for me) balance poses, which the willet seems able to maintain for hours. But why? No warrior or downward dog for the willet, just this, well, bird posture. Sometimes when one leg is drawn up so far as to disappear, I have thought this poor one-legged willet must have lost a leg to a predator or an accident until the missing leg emerges and joins its partner on the sand. But, there’s a reason for most everything in nature, why the one-legged stance?

As I am sure you have already guessed, it relates to the “rete mirabile” in the legs and feet of many birds, especially those with longer, unfeathered legs subject to heat loss to the environment. Rete mirabile, coined by the Roman physician and philosopher, Galen, means “wonderful net” in Latin and refers to physiologic arrangements in many creatures in which vessels carrying blood in opposing directions exchange something - gases (fish gills), ions (mammalian kidneys), or, in the case of willets, heat. Warm outgoing arterial blood runs very close to cooler returning venous blood. For the willet, this brings the temperature of the legs closer to the ambient external temperature reducing heat loss from the bird’s warmer body. And, pulling one leg up close to that warmer body further cuts the heat loss from the exposed legs in half. Somehow this has never worked to my advantage in yoga class maybe due to the heat lost through embarrassment.

Willets are among the largest of the North American sandpipers. The eastern version breeds in the summer in coastal areas from the Canadian maritimes to the southern tip of Florida and along the Gulf Coast to Mexico. In winter the most northern flocks join their non-migratory brethren south of Virginia or on the islands of the Caribbean. Western willets breed on in-land marshes and wetlands across the Great Plains then winter on both the west and east coasts. Willets tend not to socially distance, and their congregations are sometimes called “contradictions” or “binds” or “flings.” (Though I have come to believe all of the far-fetched names for groups of birds to be suspect products of idle minds.)

Willets are fairly nondescript birds. But, you can recognize them by their size, by the striking white stripe across their wings when they take flight, and by their distinctive “pill-will-willet” song.