The New Neotropical Companion

16- 82) reaches a length of 145 cm (57 in); it and its close

relative the Red Tegu (T. rufescens), are the two largest

lizard species of the Americas. The Common Tegu

(T. teguixin; plate 16- 83), which sometimes reaches

1 m (39 in) in length, is perhaps the most commonly

encountered species. Tegus live in forested areas and

forest borders, but may also frequent savannas and

even beaches. They feed on small animals, including

chickens and their eggs, and local farmers hunt them

as a protein source.

Gekkonidae, the geckos, is a major lizard family of

the world’s tropics. Geckos are usually pale colored

with dark splotches (plate 16- 84). With adhesive scales

on their feet, geckos cling comfortably to smooth walls.

They feed exclusively on arthropods and are nocturnal.

Some species inhabit dwellings, living in harmony

with humans. Geckos are considered valuable for their

ability to keep numbers of cockroaches and other

vermin within tolerable limits. The name gecko comes

from their loud calls, given only at night, often while

hanging on a wall rather near where you’re sleeping. It

takes some getting used to.

Many more species of snakes and lizards (plate 16-

85) inhabit the Neotropics, but the ones discussed and

shown here ought to give you the general idea of the

remarkable biodiversity and beauty.

Anurans: Tree Frogs, True Frogs, and Toads

Amphibians are vertebrates that do not lay eggs

in protective shells. Instead, they require water to

reproduce. Typically, gelatinous eggs are laid in ponds

or streams, either as floating masses or attached

to rocks or debris. Larval animals (referred to as a

tadpoles in frogs and toads) hatch and pass through

a developmental stage in water. During this aquatic

phase the animal breathes by external gill tufts, but

these are resorbed when the larva passes through

metamorphosis to adulthood. Adult amphibians

usually require moisture for their skins, though toads

are able to survive with dry skins.

Salamanders are not diverse in the tropics. They

represent an exception to the general tendency for

taxonomic groups to show high species richness in

the tropics. By far the most abundant, diverse, and

interesting amphibians are the anurans, the frogs, tree

frogs, and toads.

There are approximately 4,000 species of anurans

in the world, and some 1,600 occur in the Neotropics

Plate 16- 84. The Yellow- headed Gecko (Gonatodes albogularis)

is widely distributed and common in Central and South

American humid forests. Photo by Dennis Paulson.

Plate 16- 85. Berthold’s Bush Anole (Polychrus gutturosus), also

popularly called the Forest Iguana, occurs from Honduras

to Ecuador. It shows the remarkable beauty typical of many

snakes and lizards. Photo by Dennis Paulson.

chapter 16 from monkeys to tarantulas: endless eccentricities 355