Penguin Pomp Birds of a Feather

A flock of gentoo penguins at the Tennessee Aquarium in Chattanooga puts on a show. At heights of almost 3 feet (1 meter), gentoos are the third largest penguin species in the world. Gentoos build nests out of round, smooth stones, which are highly prized by females. To curry favor with a potential mate, male gentoos sometimes present gifts of these coveted rocks.