2008 has been designated as the Year of the Frog, hosted by the Association of Zoos and Aquariums in America, and is recognized in countries all over the world. Why a "Year of the Frog"? Because one-third to half of all frog species are threatened with extinction, and around 120 species have gone extinct in recent years. This is the biggest potential mass extinction of one group of creatures since dinosaurs, and the Year of the Frog calls attention to the alarming decline of frogs globally.
No one knows the exact cause of this problem, but some lead factors include global warming (wetlands drying up, less humidity, frogs waking up too early from hibernation); pollution (air and water pollution kills frogs); habitat destruction (draining of wetlands and cutting forests for development); invasive species (eastern bullfrogs introduced in the west have decimated local native frogs); pet trade (over-collection of some species and release of exotic or disease-carrying pets into the wild); and chytrid fungus (fungus killing frogs worldwide with no cure, and made worse by all of the above environmental issues).
Many people have misconceptions about frogs. Although you may think you can get warts from frogs, it's simply not true. Warts are really parotid glands that produce toxins that make toads taste bad to predators, and are not contagious. Frogs also do not always make a "ribbit" sound -- they actually make a wide range of noises. They do not, however, make a good pet for kids. Because of their sensitive skin, frogs should not be handled regularly, and require a lot of special care.
All frogs are carnivorous and feed voraciously on insects and other small animals, a task that is important for agriculture, gardening, and control of insect-borne diseases. Liquids and gasses are absorbed through their sensitive skin -- frogs are much like "canaries in the coal mine" because they are very susceptible to environmental pollution and change. In fact, the skin secretions of frogs are being studied for human medical benefits.
The only frog species that lives north of the Arctic Circle, wood frogs have antifreeze-like properties in their body fluids that allow them to freeze solid without dying. They breed in vernal pools -- small ponds that fill up in spring and dry up in summer and don't contain fish, which would eat the eggs and tadpoles. They lives in woodlands, are perfectly camouflaged to look like dead leaves, and emit a breeding call that sounds like ducks quacking.
Often mistaken for a bullfrog, the green frog lives across the eastern United States in ponds, slow streams, and lakes. With a distinctive bright green "moustache," they emit a breeding call that sounds like the pluck of a banjo string.
Found in wet woodlands and fields, pickerel frogs have rows of square brown spots on a tan or olive background. They produce toxins in the skin that make them unpalatable to predators, and emit a breeding call that sounds like a long snore.
With short stocky legs adapted for walking and short hopping rather than leaping and swimming, the American toad lives in wooded areas and fields, only visiting water for breeding in the spring. With brown, gray, and tan coloration that helps camouflage them on rocky terrain or dead leaves, American toads have no webbing between their toes and emit a long, trilling "brrrlll" sounds when breeding.
Special thanks to Savio Engineering and Freedom Islandscapes for constructing the pond on our set; to Connecticut's Beardsley Zoo for providing these wonderful creatures; to David Mizejewski for sharing this information; and to the National Wildlife Federation and Creative Homeowner for giving a copy of David's book, "Attracting Birds, Butterflies, and Other Backyard Wildlife," to everyone in our studio audience.