JUST HOW FASCINATING CAN A FROG BE?

by Whit Gibbons

February 5, 2006

Do you think of frogs and toads as no more than fat, hopping, croaking blobs? Do you think they are only good for threatening preteen girls (assuming you’re a preteen boy)? Do you think frogs have drab personalities with coloring to match and are about as interesting biologically as slugs? If you do, there’s a new book that will change your mind. And if you’re already convinced that frogs are fascinating, you’ll get further confirmation from this book.

Frogs: Inside Their Remarkable World (2005; Firefly Books, Toronto) by Ellin Beltz is a 176-page book with 125 stunning color photographs. The hardcover book is $34.95, an amazing bargain. The more than 4,000 species of frogs offer an array of diversity in behavior, ecology, and appearance. Frogs (which in the broadest sense also include the toads) live on virtually every large island and continent in the world except Antarctica. One, however, does live north of the Arctic Circle, surviving winter hibernation by converting its body fluids into a form of antifreeze, and another is found in the Himalayas at elevations of 17,000 feet.

As its title implies, the frog book unveils a remarkable amphibian world that will be appreciated by anyone exposed to it. The world's largest frog, the goliath frog of the Cameroons in West Africa, can weigh up to eight pounds and is almost a yard in length when its legs are extended. By comparison, the American bullfrog can weigh around four pounds and is about a foot in length. The largest toad is the marine toad or cane toad native to the American tropics that can be almost two feet long and weigh up to six pounds. Imagine a six-pound toad! In contrast, adults of the world's smallest frogs are only 3/8 of an inch long, smaller than any other land-dwelling vertebrates. For perspective, two of these frogs could sit end-to-end on a nickel without touching the edges. One is the Brazilian gold frog, and the other, discovered in Cuba in 1996, has no common name. Actually, I guess we could name it here as "the Cuban mini-frog."

One point that cannot be overstated about this book is that the photography is superb. The pictures bring out the endless spectrum of lively colors, and many also capture the array of bizarre behaviors displayed by frogs. As far as color, the Oriental fire-bellied toad, green above and red below, is hard to beat, until you see the blue color phase of the Australian green treefrog. The blue color is highly unusual among frogs and has only recently been verified as existing in the Australian species. Other oddities include a pileup of two dozen African gray treefrogs kicking their legs to create a foamy froth to lay their eggs in, and the broadly webbed front and back feet of Reinwardt's flying frog, a yellow and green Malaysian species that glides from the tops of tall trees.

Some of the interesting facts that accompany the author's well-written text and the assortment of color photos, maps, and charts, include ones that sound like something from a frog and toad high school annual. The award for "most prolific" goes to the marine toad, which has been known to lay more than 35,000 eggs. Do not ask who counted them. The award for the biggest mouth (for which most of us could recall a sure winner in our high school), belongs to algae-eating tadpoles. They are able to open their mouths 180 degrees, which means straight up and down. Although almost all frogs and toads are confined to terrestrial or freshwater habitats, the Southeast Asian crab-eating frogs live in brackish mangrove swamps by changing their body chemistry.

Frogs: Inside Their Remarkable World will convince you that frogs are amazing, but do not get the idea that all the exciting ones are only in the tropics or other faraway lands. Right now, several winter-breeding frogs, including the aptly named ornate chorus frog, are calling and breeding in protected wetlands of the Southeast. Frogs have much to tell us about the mysteries of nature, and we need to keep listening for them wherever they are.



If you have an environmental question or comment, email