Canadian winters are not for the faint of heart—but photographer Mark Williams braved the sub-zero temperatures in his quest for the perfect shot. Williams spent several days out in the cold observing this snowy owl, and eventually she seemed to accept his presence. "She was most active in the cold, as her hunger drove her to hunt," he says.
Williams snapped this photo just as the owl took off from a nearby fence post, which she often used as a vantage point while looking for prey. As she turned into the wind, she gave Williams a kind of "shoulder check," and the unusual pose was immortalized in his well-timed photo.