SNPL

Snowy Plovers in winter prefer the perceived safety and warmer micro-climate of shallow depressions when flocking together on the beach. The color of their backs is strongly matched with the substrate, so that when they sink their snowy white bellies down below the surface of the beach, they are quite hard to pick out--for us surveyors and predators alike. Additionally studies have been done to prove that the temperature in depressions averages higher than on the beach surface, due to protection from wind, so a bird that consistently utilizes depressions in the cold winter months has a higher chance of survival. Footprints (human or horse), in a twist of fate, actually enhance the habitat, providing a tight network of plover-sized depressions that allow them to both keep warm and stay together. As one who surveys them, this behavior makes them both easier and more difficult to study. Hiding in a footprint makes your legs, and consequently your unique leg band combos, pretty much impossible to see--but at least you know where to look for the birds.