The main reasons for the disappearance of the Saint Croix ground lizard on Saint Croix Island are habitat loss and the introduction of a mammalian predator, the Indian mongoose (Herpestes auropunctatus), both of which continue to threaten the future of the species in its remaining range (2). There is evidence that the decline on Saint Croix Island correlates with the introduction of the Indian mongoose in 1884 (2). The accidental introduction of the mongoose onto Green, Protestant or Ruth Cay could be catastrophic, most likely resulting in the extinction of the species (7).
Extensive development of coastal areas probably also contributed to the disappearance of this lizard on Saint Croix (2), and poses a significant threat to remaining populations. Suitable habitat is rapidly diminishing on Protestant Cay due to landscaping practices by hotel management, including activities such as raking, removal of leaf litter and undergrowth, and planting of exotic vegetation (8). A second concern is the vulnerability of the Saint Croix ground lizard to natural disasters such as hurricanes that strike the islands of both Green and Protestant Cay (2).
With such small, isolated populations, the Saint Croix ground lizard now faces the additional threat of reduced genetic variation through inbreeding, which would make it more vulnerable to natural disasters or disease as well as having a negative impact on fertility (7).