GIS-based distribution, population estimation, and morphological variation of Brown sand boa (Eryx johnii Russell, 1801) from Cholistan desert, Pakistan

Abstract

Pakistan has a rich diversity of herpetofauna. While numerous diversity studies on snakes have been carried out in Sindh and Baluchistan regions, none exists on the Cholistan desert landscape. Therefore, we aimed to conduct a one-year study on the different microhabitats of the Cholistan desert, to estimate the distribution and density of Brown sand boa (Eryx johnii). The sampling techniques include hand-picking, pitfall traps, and opportunistic visual encounters by amateur trackers. During the present study, 36 specimens of E. johnii were recorded for the assessment of the GIS-based distribution of species from the study area. E. johnii was recorded from 20 localities in the Cholistan desert. Further, we identified five different microhabitats have been identified from the study area for population estimation and morphological variation of E. johnii. The relative abundance of males, females, and juveniles was 0.5, 0.33, and 0.6, respectively. Morphologically, the males are significantly larger and heavier than females. We recorded two types of coloration, i.e., yellowish and reddish morphs, from various habitats of the Cholistan desert. This study provides important information on the distribution and density of the Brown sand boa in the understudied Cholistan desert landscape. The current study evaluates the distribution ranges of Brown sand boa to estimate the population density for their conservation in current localities. More investigation is required to evaluate the diversity and distribution of other species in the area because the one-year study timeframe and use of amateur trackers may have produced bias in data collecting.

Keywords

• Cholistan desert
• Eryx johnii
• morphological character
• population estimation