by Whit Gibbons

March 24, 2013

Is the GEICO gecko anatomically correct? Is it really speaking in an Australian accent? What kind of gecko is it modeled after? The answers to these questions and many others can be found in "Geckos: The Animal Answer Guide" by Aaron Bauer (Johns Hopkins University Press, 2013). This book is recommended if you are considering getting a gecko for a pet or if you just want to know more about the ecology and behavior of the 1,400 or so living species of these peculiar lizards.

Commonly asked questions are followed by answers from the author, who is an expert in the field, having traveled around the world in search of geckos. Geckos are found mostly in warm climates, with Australia being home to the most different species, about 175. Madagascar has more than 100, and many countries in Asia and Africa have more than 60 species. Contrast such diversity to the paucity of geckos found in the United States: a single native species (the Florida reef gecko) in the East and a handful known as the banded geckos in the Southwest. Of course, numerous species from other countries have now been introduced into Florida and taken up residence there and elsewhere in the United States.

Among the questions people often ask about various groups of animals, including geckos, are what is the largest and smallest species, how long do they live, and do they bite? Geckos are not that impressive in size, as most are less than 3 inches long. The biggest gecko in the world (the New Caledonia giant gecko) has a head and body length under a foot. The smallest ones are the dwarf geckos of the West Indies, with body lengths barely over half an inch. As adults, the dwarf geckos are the smallest among the reptiles, birds and mammals in the world.

Most geckos are too small to bite or, if they do bite, the consequences to humans are minimal. But a few large species deserve special mention. One of the most serious biters is the tokay gecko, which is commonly kept as a pet. The author recounts a bite from one that held on for 20 minutes. Some geckos live extraordinarily long lives, with two species documented to have lived more than 35 years. The western banded gecko of the U.S. Southwest, which is only an inch long at birth and reaches a maximum length of about 6 inches, has been known to live more than 34 years in captivity.

Each Animal Answer Guide book has black-and-white photographs appropriate for particular sections. In the chapter titled "Form and Function" is a photo of a Bibron's gecko, native to South Africa, showing how in some species the gecko can intentionally break off its tail to escape predators. Other illustrations show close-ups of the remarkable expanded pads under the toes that allow geckos to walk up vertical walls and adhere to almost any surface. In addition, 35 color photos show the startling array of body coloration and patterns as well as the striking morphology of this impressive group of lizards. The range of gecko colors, as seen in the photo galleries, includes green, yellow, orange and pink, plus numerous shades of brown and gray.

As for the GEICO gecko, it is anatomically incorrect for two reasons. First, it has eyelids. Most geckos do not have movable eyelids. Instead a clear scale called a "spectacle" covers and protects the eye. Second, its thumb is disproportionately large for a gecko. The accent is not Australian but the Cockney of East London. And as for which of the more than 1,000 geckos it might be modeled on, the best guess is one of the beautiful day geckos, perhaps the giant day gecko of Madagascar that has been introduced to and is now living happily in both Florida and Hawaii.

Other questions in the book are "why do geckos lick their eyes?" and "what are flying geckos?" You know where to find the answers.

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