Lauren Chan

Conservation and landscape genetics of the

Dunes Sagebrush Lizard, Sceloporus arenicolus


Above: Shinnery-Oak and sand dune blowouts.

The Dunes Sagebrush Lizard is tied to the shinnery oak dominated sand dune landscape of SE New Mexico and adjacent Texas. They rely on this mosaic of sand dune blowouts (sandy depressions clear of vegetations) and shinnery oak (Quercus havardii) expanses for reproduction and survival.

Herbicide treatment and oil and gas mining have altered the landscape considerably. The former converts shinnery oak habitat to grass and mesquite dominated habitat that generally lacks the vegetative cover and microhabitat structure important to S. arenicolus persistence. The wellpad and road construction associated with oil and gas mining destroys and fragments habitat. Below are aerial photographs from Google Earth of (a) intact habitat, (b) habitat once treated with herbicided (light colored patch), and (c) wellpads and roads in suitable S. arenicolus habitat.

Above are aerial photographs from Google Earth. In all photos, the cresent shaped patches are sand dune blowouts that are potential S. arenicolus habitat. From left to right the images are (A) intact habitat, (B) habitat with a patch previously treated with herbicide (the light colored patch), and (C) wellpads and roads in suitable S. arenicolus habitat.

I am collaborating with colleagues at Texas A&M to better understand the influence landscape features on the population ecology and persistence of this species of conservation concern. Specifically, I am using genetic markers (e.g. DNA sequence data, microsatellite genotypes, and genomic data) to address how natural and anthropogenically related aspects of the landscape influence population genetic diversity and population connectivity at multiple spatial scales. We are looking at range-wide patterns of differentiation across evolutionary time scales as well as at contemporary patterns in genetic diversity and connectivity fine spatial scales across 27 experimental mark-recapture plots.

Above: Sceloporus arenicolus in the Mescalero Sands.

Some questions we're addressing are:

  1. What is the evolutionary history of S. arenicolus throughout their range and how does this inform broad scale management of the habitat and species?
  2. How do habitat modifications associated with oil and gas development influence the likely persistence of local populations?
  3. Can landscape genetic models identify features important to population connectivity and, in turn, predict howfuture landuse practices might impact extant populations?
  4. And finally, how do other co-occuring species with differing ecologies utilize these unique habitats? Are barriers to S. arenicolus movement also barriers to connectivity in whiptail and side-blotched lizards and what are the implications for their persistence?