human cultures throughout this species distribution, the clades are being evaluated for their impact from humans. For example, these iguanas are not eaten in their northern ranges by humans as they are in the southern ranges, but the hatchlings in the southern ranges have a better survival rate due to better environmental conditions. Description C. pectinata has distinctive keeled scales on its long tail, to which its common name refers. It is one of the larger members of the genus Ctenosaura, capable of growing to 1.3 m (4.3 feet) in total length (including tail), with females being slightly smaller than males at . It is usually brown or grey-brown in coloration dorsally, with a yellowish ventral surface. It has a crest of long spines which extend down the center of its back. Hatchlings are often a bright green color with no body pattern, and darken as they age. Ctenosaura pectinata often (but not always) has an irregular piebald pattern on the head or dorsal areas. Although the tail may be banded with light and dark crossbands, C. pectinata typically lacks a clear or well developed crossband pattern on the body, which is often present in the similar appearing and closely related species Ctenosaura similis and Ctenosaura acanthura.Ctenosaura pectinata varies from gray to a brownish-black, with some males exhibiting yellowish colors, and females orange color, on the lateral sides of the body. The young are bright green and unmarked except for black tail bands, present also on adults. Distribution C. pectinata is native to Western Mexico from Sinaloa to Oaxaca. This iguana has been introduced to Brownsville, Texas and South Florida and reproduces in the wild in several feral populations. On the south-eastern Florida coast, these iguanas have been found on Key Biscayne, Hialeah, and in Broward County. On the south-western Florida coast, it has been reported on Gasparilla Island. It is currently estimated as of December 2007 that there are 12,000 iguanas on this island, descended from a trio of pet lizards released by a resident in the 1970s. They are regarded as a "nuisance animal" on Gasparilla island because the iguanas eat ornamental flowers and shrubs and prey on nesting birds and sea turtle eggs. They have been known to chew through electrical and telephone cables. They may also carry salmonella and their appearance has been known to scare timid residents. As the iguanas like to burrow in the