Northern Curlytail Lizards

The northern curlytail lizard (Leiocephalus carinatus armouri) is endemic to the islands of the Little Bahama Bank, with other subspecies found in the Great Bahama Bank, Cayman Islands, and Cuba (Schwartz and Thomas 1975, Schwartz and Henderson 1991). A small colony established in Palm Beach County through the intentional release of 20 pairs in the 1940s has spread widely (Duellman and Schwartz 1958). Prior to 1968, the range for this population had been expanding north and south along the Atlantic coast at an average rate of 0.98 km/yr, but from 1968 to 2002 it expanded at a much greater average rate of 2.4 km/yr (Smith et al. 2004; Smith and Engeman 2004), and is continuing to expand. Moreover, curlytail lizards are also found in disparate parts of south Florida through human translocations (e.g., Meshaka et al. 2005).

The primary concern with this species' (rapid) range expansion is its depredations on other (small) lizards (Meshaka et al. 2005). Saurophagy is a component of the northern curlytail's ecology (e.g., Smith and Engeman 2004, Dean et al. 2005), and the widely-distributed, also exotic, brown anole (Anolis segrei) is a known prey species that could provide expanding populations with a nutritious prey base and a simultaneous reduction in competitors (Meshaka et al. 2005). The northern curlytail is aggressive towards fauna in its size class and was even observed to attack a juvenile northern mockingbird (Mimus polyglottos) (Smith and Engeman 2007), the adults of which prey on northern curlytails (Smith et al. 2006). This potential displacer/replacer for the brown anole likely will put the native lizard fauna with which the northern curlytail exists at risk, including state-listed species (Meshaka et al. 2005). The negative impacts would be especially critical in human-disturbed habitat where the northern curlytail lizard is expanding its range and native lizards might already be marginalized.

Although the northern curlytail is unlikely to receive much attention outside herpetological circles, it was described in one newspaper article as "the T-rex of ground critters" (Fleshler 2006). Nevertheless, the northern curlytail lizard, like many of Florida's small-to-medium sized invasive lizards, is unlikely to be targeted for control or eradication.

Its ubiquity within its extended range, small size, and the difficulty in isolating it for control in the presence of native lizard species would make control or eradication difficult, prohibitively expensive, and without the high profile that would engender public support.

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