CAPE CANAVERAL, Fla. - A great blue heron stands tall in the water, perhaps looking for food, on grounds of NASA's Kennedy Space Center in Florida. More gray than blue, with a yellowish bill and black legs, it has a brownish-buff colored neck with a black border and white in front of its neck with a vertical black streak. The bird's head is white with a black stripe above its eye. They range throughout the U.S., inhabiting lakes, ponds, rivers and marshes. Their principal food is fish or frogs but may feed on small mammals, reptiles and occasionally birds. Kennedy shares a boundary with the Merritt Island National Wildlife Refuge, which is a habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles.