What is this Tricolored Heron (Egretta tricolor) doing as it raises its wings and dances in circles in the coastal bay marsh on Assateague Island? It’s called shadow fishing or canopy fishing and apparently it’s a behavior that’s not well understood.
Some speculate that by casting a shadow with its wings a Tricolored Heron can improve its view of underwater prey. Others suggest that the shadow lures out tasty fish, amphibians and crustaceans that equate a shadow with cover. Shadow feeding is just one of several foraging behaviors employed by Tricolored Herons. They also stalk and wait; lope and chase; lunge; scrape the bottom; even grasp a small fish out of the air. All in all, they are an entertaining wader to watch.
Maryland is at the northern edge of the Tricolored Heron’s range, so it is a treat to see this handsome bird in action.