Iguana_11.1_bw_text House Geckos in the genus Hemidactylus are widely distrib- uted throughout the tropics and subtropics of the Eastern Hemisphere. As the common name implies, they often function as human commensals. Consequently, these lizards are particularly prone to “hitch-hiking,” and several species have become estab- lished in the Americas. At least three forms, H. haitianus in the Greater Antilles, H. leightoni in Colombia, and H. palaichthus in northeastern South America, have diverged sufficiently from their ancestors to be considered endemic Neotropical species. Hemidactylus turcicus, native to the Mediterranean region, is common in the southeastern United States. It has expanded its range considerably after presumably arriving originally in Florida. At least one individual found its way to Missouri in a travel trailer purchased in Florida. Hemidactylus garnotii, of the South Pacific, is firmly entrenched in Florida and has established satellite popu- lations throughout the New World. Hemidactylus mabouia, orig- inally from sub-Saharan Africa, is widely distributed in eastern and northern South America and much of the Caribbean area. It has recently become increasingly common in southern Florida and apparently is displacing H. turcicus in most of the southern peninsula. Its passage across the Atlantic from Africa may have predated human traffic. The most recently established newcomer is the Asian House Gecko, H. frenatus. All of these species are effective colonizers that either have or are currently expanding their ranges, “leap-frogging” from port to port or city to city in baggage or freight or as eggs in plants and shipments of lumber. The site of the first established population of H. frenatus in the Western Hemisphere is unknown, but the species has quickly become abundant throughout much of the Neotropics, in some areas apparently displacing related species that had become estab- lished years earlier. As recently as the mid-1980s, this species was unknown in Costa Rica. By the early 1990s, it had become ubiq- uitous in towns and resorts of the Pacific Lowlands and is now found in Caribbean ports and several inland localities, suggesting that range expansion is ongoing. Although individuals occasionally are found in natural habi- tats, House Geckos usually associate closely with humans. They are abundant in almost any type of structure, gathering in large numbers to feed on insects attracted to neon lights of business establishments or emerging at night from light fixtures and from behind picture frames to forage on walls and ceilings. References Lever, C. 2003. Naturalized Reptiles and Amphibians of the World. Oxford Univ. Press Inc., New York. Savage, J.M. 2002. The Amphibians and Reptiles of Costa Rica: A Herpetofauna Between Two Continents, Between Two Seas. University of Chicago Press, Chicago, Illinois. 20 IGUANA • VOLUME 11, NUMBER 1 • MARCH 2004 S P E C I E S P R O F I L E Asian House Gecko (Hemidactylus frenatus) Robert Powell Avila University, Kansas City, Missouri An adult Hemidactylus frenatus on a television screen in Jaco, on the Pacific Coast. POWELL