The Common or Gray Potoo is a nocturnal bird related to the nightjars. However, it lacks the bristles around the mouth found in true nightjars. Its pale gray to brown coloration finely patterned with buff and black makes the Potoo blend in as an extension to the log on which it is perched. During the day, this allows the bird to be perfectly camouflaged. However, at night its large orange eyes, which reflect light from a spotlight, announce the bird's presence. The Potoo has a distinctive, haunting song. We were birding near the small pavillion located on the Poço Preto (Black Well) Trail in Iguaçu Falls National Park. Temperatures were in the 70's on this rainy, overcast morning.