Maps showing the potential distribution and abundance of <i>Gopherus flavomarginatus</i>.

<p>(A) Inferred abundance for the Bolson tortoise (burrows/Km²); red dots pinpoint the sites where the abundance data for the Bolson tortoises was recorded. (B) Standard deviation of abundance.</p

Geographic distribution of <i>Gopherus flavomarginatus</i>.

<p>The thick black line delineates the polygon of the Mapimí Biosphere Reserve, whereas the state borders are mark by the thin black lines. Red dots pinpoint the sites where the abundance data for the Bolson tortoises was recorded. The star indicates the location of the Mapimí field station.</p

Relationship between the observed abundance (burrows/Km²) of <i>Gopherus flavomarginatus</i> and the distance to the species´ ecological niche centroid.

<p>Relationship between the observed abundance (burrows/Km²) of <i>Gopherus flavomarginatus</i> and the distance to the species´ ecological niche centroid.</p

Validation for the Inverse Regression Model between Mahalanobis distance to the ENC and burrow abundance.

<p>Validation for the Inverse Regression Model between Mahalanobis distance to the ENC and burrow abundance.</p

Climate and topographic variables used for inferring the ecological niche and abundance models of the Bolson tortoise.

<p>Climate and topographic variables used for inferring the ecological niche and abundance models of the Bolson tortoise.</p

Recorded abundance of <i>Gopherus flavomarginatus</i> expressed as the number of burrows/Km².

<p>Roman numerals before the district name correspond to the designation assigned by Bury <i>et al</i>. [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0131452#pone.0131452.ref029" target="_blank">29</a>].</p><p>¹ MCR = Mapimí Central Region</p><p>^<b>2</b> District V was modified and we included the state of Chihuahua because several sites lie within this region.</p><p>Recorded abundance of <i>Gopherus flavomarginatus</i> expressed as the number of burrows/Km².</p

Goodness-of-fit of the regression models between Mahalanobis distance to the ENC and burrow abundance of <i>Gopherus flavomarginatus</i>.

<p>¹ Results inferred from Akaike Information Criterion (AIC)</p><p>Goodness-of-fit of the regression models between Mahalanobis distance to the ENC and burrow abundance of <i>Gopherus flavomarginatus</i>.</p

Proposed key sites (yellow polygons) for the conservation of the Bolson tortoise, <i>Gopherus flavomarginatus</i>.

<p>The red line delineates the current protected polygon of the Mapimí Biosphere Reserve. Sierra del Diablo (A) and Sierra Mojada (B) represent putative high abundance sites; nonetheless, these are low priority areas due to their natural isolation and low human population density.</p

Results of successful classification in morphological-space (males/females) and environmental-space (localities), with percentage in parentheses, assigned to each clade by discriminant analysis.

<p>The numbers in the cells indicate the number of individuals, followed by the percentage in parentheses. Overall percentages of successful classification are given in parentheses for males, females and localities.</p><p>Results of successful classification in morphological-space (males/females) and environmental-space (localities), with percentage in parentheses, assigned to each clade by discriminant analysis.</p

Niche overlap (Schoener's D index) and Identity Test for clades within <i>Pristimantis acuminatus</i> complex.

<p>D-values are compared to the null distributions for each pair of species (clades A–D); P-values are provided for each comparison.</p><p>Niche overlap (Schoener's D index) and Identity Test for clades within <i>Pristimantis acuminatus</i> complex.</p