© AMNH / Denis Finnin
Though some in its huge family prefer the daylight, nighttime is the right time for this large gecko.
Spines may help protect the eyes when these nocturnal geckos burrow in soil or hide in leaf litter during the day. For the past century, the Crested Gecko has played hide-and-seek with humans. Because no one saw a specimen for a century after its discovery in New Caledonia in 1866, scientists assumed it was extinct. Then, after a tropical storm in 1994, a single animal turned up. We now know it is widespread in the islands of New Caledonia, 1,600 km (1,000 miles) east of Australia.
The large holes behind its mouth are this gecko's ears. Like many animals active at night--when vision is limited--they have a highly developed sense of hearing.
Vertical pupils help block light from this gecko's sensitive eyes. At night, the pupils open wide.
When disturbed during the day, the Crested Gecko raises up on four legs to look bigger, opens its mouth wide . . . and hisses loudly.
These swellings on either side of the tail are the site of the male gecko's paired reproductive organs. All male squamates--and no other vertebrates--have these paired structures, called hemipenes.
NAME: Crested Gecko; Rhacodactylus ciliatus
SIZE: 18 to 20 centimeters (7 to 8 inches)
RANGE: New Caledonia
© John Cancalosi / naturepl.com
New Zealand common green gecko (Naultinus elegans)
Meet the Family
The gecko family--Gekkonidae--is huge. It includes about 1,000 species, or well over 10 percent of all squamate species on Earth. And like any big family, it displays a lot of variety-in size, in shape, in lifestyle. Some family members are active at night, and some during the day; some have eyelids, and some don't; some don't even have legs.
New Zealand Common Green Gecko Naultinus elegans
Most geckos lay eggs, but this is one of the few species that bears live young. It lives only in New Zealand.
© Thierry Montford / BIOS / Peter Arnold, Inc.
Leopard Gecko Eublepharis macularius
While walking, this animal holds its body up off the ground and sometimes curls its tail in a posture like that of a scorpion. It lives in southwestern Asia and western India.
© Michael & Patricia Fogden / Minden Pictures
Namibian Barking Gecko (Ptenopus garrulus), Male
Namibian Barking Gecko Ptenopus garrulus
Every day, these southwest African animals announce their presence by "barking" as they emerge from their burrows at sunset to begin a night of activity.