Distribution and Abundance of the Central American River Turtle, Dermatemys Mawii, in Southern Quintana Roo, Mexico: Implications for a Regional Conservation Strategy

Abstract

We estimated the distribution and abundance of the Central American River Turtle, Dermatemys mawii, in four aquatic systems in southern Quintana Roo, Mexico. Using nets and free diving we captured 52 individuals D. mawii among the winter, dry and rainy seasons. We recorded 12 variables to characterize the habitat and correlated these with the abundance of D. mawii. Using catching per unit effort, we evaluated the species' relative abundance for each aquatic system. Using Maxent, we modeled the potential distribution of D. mawii using historical and present locality data. We recorded 81 D. mawii individuals using systematic sampling and casual observations. La Union was the site with the highest relative abundance (~4 ind.-net). We found a negative correlation between D. mawii abundance and salinity. The model of potential distribution identified sites with ecological conditions suitable for the species where it is undocumented. Information about the ecology of this species remains scarce, but we propose that identifying management units could improve conservation of the species at local and regional levels.

Genetic Relationship Between Founders of a Threatened Freshwater Turtle in a Mexican Wildlife Management Unit. A Conservation Strategy

“…These results suggest that the wild founding population was probably small which is to be expected considering that D. mawii is almost extirpated in Mexico and is exceedingly rare and difficult to capture (Vogt & Flores-Villela, 1992). For example, in the Rio Escondido catchment basin, southern Quintana Roo, Calderón-Mandujano et al (2017) captured 52 D. mawii individuals (a mean of 1.74 turtles caught per net) from February 2009 to August 2010 and recorded a low recapture rate during their field samplings (three individuals). In the northeastern part of the Pantanos de Centla Biosphere Reserve (RBPC, Tabasco), (eight nets and 384 hours of catches per net) very few turtles were captured; a mean of 0.312 and 0.041 turtles caught per net for the Tabasquillo and the Grijalva Rivers respectively during the dry season, and a mean of 0.500, 0.083, and 0.041 turtles caught per net in the Tabasquillo, the Grijalva, and the Usumacinta Rivers respectively during the rainy season (Zenteno-Ruiz et al, 2010).…”

“…The Central American river turtle, D. mawii , is an important species for conservation; it is the last representative species of the Dermatemydidae family and is endemic to Mesoamerica with a distribution from the southeast of Mexico to Belize and Guatemala (Vogth et al, 2011). Wild populations of D. mawii have been hunted and illegally trafficked, and their habitat has become so fragmented that the population of this species has suffered a significant decrease in population over the last few decades (SEMARNAT, 2014; Calderón-Mandunajo et al, 2017; Jennings et al, 2020). Therefore, this turtle species is considered among the 25 most threatened species of turtles in the world (Turtle Conservation Coalition, 2018).…”