Print PageThe Honduran Paleate Spiny-tailed Iguana, Ctenosaura melanosterna, is a critically endangered endemic with two small, fragmented populations in Honduras; one on the mainland and the other on an archipelago off the northern coast, that face differing human pressures. We used a four-year capture-mark-recapture study, consisting of 1254 resights/ captures of 658 individually marked iguanas from 2007-2010 to understand the effects of these varying human pressures on the island population of Ctenosaura melanosterna. We chose four sites using variables of human density, human molestation, supplemental food/ water, and island size to detect differences in relative densities, morphometrics, and behavior of this lizard. Additionally, we conducted a series of trials on individual iguanas at each site to test for behavioral differences
Results/Conclusions
Our results showed differences in both individual and populations of iguanas for each site in response to the varying human pressures. Specifically, we found that areas of high human densities correlated with high iguana densities, as long as iguanas were left undisturbed. However, if iguanas were molested, sizes remained the same, regardless if there was supplemental feeding or not, and only behavior changed. Additionally, area only had an affect on iguanas with high human molestation, despite receiving supplemental food and water, resulting in shorter snout- vent lengths and lower masses. Our results show the single most important variable influencing iguana population densities, sizes, and behavior is the level of human molestation. It is important for wildlife managers to recognize that human density in of itself is not detrimental to C. melanosterna populations, but rather the key factor is that the reptiles are not molested. These data are critical for understanding how to best create management plans for this critically endangered species in a human inhabited archipelago setting.
