Threats

The Sand Dune Lizard is highly adapted to life in the sand. Its sand-bury and sand-swimming abilities and cryptic coloration attest to the close evolutionary ties between this lizard and the coastal dunes. Its situation is even more critical given the severe alterations experienced by the coastal habitats in pampas region, because it cannot colonize and survive in other habitat types. Studies carried out in a dune sector called “Mar del Sur” have shown that this species is highly sensitive to habitat alteration; minor disturbances such as the establishment of a trail for 4 x 4 vehicles can seriously affect its natural populations, causing a critical drop in population density and eventually leading to localized extirpation (Vega et al. 2000). This situation is clearly evident in the dune sector situated between the towns of Villa Gesell and Cariló, where this lizard was abundant no more than 10 years ago; today it is practically impossible to find in that area.

Due to their restricted distribution, their apparently low abundance and the man-made disturbance on their habitat, the SDL has been categorized as vulnerable species (Lavilla et al. 2000). Currently there are only six remnants of natural dune areas in Buenos Aires Province that support populations of Sand dune lizards. Nevertheless, only one of these areas, namely Mar Chiquita Provincial Nature Reserve, efficiently protects one population of this lizard as a result of conservation actions (Kacoliris et al. 2006). Moreover, these areas had some natural and antropic barriers (rivers, hills and coastal towns and cities) that impede lizards interbreeding, reducing phenotypic plasticity.