Avery Michael L, Tillman Eric A, Spurfeld Conny, Engeman Richard M, Maciejewski Kelin P, Brown Jessica D, Fetzer Emily A
United States Department of Agriculture, Wildlife Services (USDA-WS), National Wildlife Research Center, Florida Field Station, Gainesville, Florida, USA.
Integr Zool. 2014 Nov;9(5):590-7. doi: 10.1111/1749-4877.12085.
The native range of Ctenosaura similis extends from southern Mexico through Panama. From an initial introduction of 3 animals in 1979, the species now numbers in the thousands on Gasparilla Island in southwest Florida. In response to complaints of property damage from residents and threats to native species, local officials and the US Department of Agriculture Wildlife Services began a removal program in 2008. Through 2011, trappers removed 9467 ctenosaurs. The number removed declined from 32 iguanas/day in 2008 to 1.9 iguanas/day in 2011 despite no easing of the control effort. We necropsied 2757 ctenosaurs to document aspects of their natural history. Females outnumbered males overall, although the largest size class (>300 mm snout-vent length) included 32 males and just 2 females. Reproduction was seasonal. We found oviducal eggs in females from early Apr to early Jun, approximately 2 months later than C. similis in its native range. We trapped hatchlings from late Jul to early Oct coincident with the summer rainy season. Clutch size increased with female body size, with 62 being the largest clutch size recorded. In general, the biology of the invasive population on Gasparilla Island resembles native C. similis populations in Central America, except for the lack of large individuals. We suggest that shorter day length and colder temperatures create environmental conditions that are suboptimal for individual growth compared to those in the native range.
刺尾鬣蜥的原生范围从墨西哥南部延伸至巴拿马。自1979年最初引入3只动物以来，该物种如今在佛罗里达州西南部的加斯帕里拉岛上数量达数千只。针对居民关于财产损失的投诉以及对本地物种的威胁，当地官员和美国农业部野生动物服务局于2008年启动了一项清除计划。到2011年，诱捕者共捕获了9467只刺尾鬣蜥。尽管控制力度并未放松，但捕获数量从2008年的每天32只鬣蜥降至2011年的每天1.9只鬣蜥。我们对2757只刺尾鬣蜥进行了尸检，以记录它们自然史的各个方面。总体而言，雌性数量多于雄性，不过最大体型组（吻肛长度>300毫米）中有32只雄性，仅有2只雌性。繁殖具有季节性。我们在4月初至6月初的雌性体内发现了输卵管卵，比其原生范围内的刺尾鬣蜥大约晚2个月。我们在7月下旬至10月初捕获了幼蜥，这与夏季雨季相吻合。窝卵数随雌性体型增大而增加，记录到的最大窝卵数为62枚。一般来说，加斯帕里拉岛上入侵种群的生物学特征与中美洲原生的刺尾鬣蜥种群相似，只是缺少大型个体。我们认为，与原生范围内相比，较短的日照时长和较低的温度创造了对个体生长并非最适宜的环境条件。
