Conservation Status and Human Impacts on Two Endangered Subspecies in the Pinacate Biosphere Reserve in Sonora, Mexico: The Sonoran Pronghorn (Antilocapra Americana Sonoriensis) and the Sonoyta Mud Turtle (Kinosternon Sonoriense Longifemorale).

Abstract

El Pinacate Biosphere Reserve, a protected area in the Sonoran Desert and the borderlands between Arizona and Sonora, was created to protect the unique and fragile biodiversity found in this place including two endangered endemic subspecies: the Sonoran pronghorn (Antilocapra americana sonoriensis) and the Sonoyta mud turtle (Kinosternon sonoriense longifemorale). These two vertebrates face numerous threats due to human development, habitat alteration, and climate change. In four different chapters we analyze and discuss some of the main issues affecting their populations. Thus, we investigated the impact of human development on Sonoran pronghorn population and its habitat with data obtained from camera traps and environmental information. We used modeling techniques to assess occupancy, habitat suitability and connectivity in the landscape. We observed adverse effects of paved highways on pronghorn occupancy mainly during the dry season. Conversely, natural features such as hillslopes and chain-fruit cholla cactus positively influenced their occupancy. We found how variables at broader scales are better predictors for pronghorn habitat suitability models. Also, we identified areas of highly suitable habitat, including potential corridors and barriers. Our findings emphasize the importance of maintaining connectivity within the entire pronghorn range. Subsequently, we provided conservation strategies for the Pinacate and surrounding areas. The Sonoyta mud turtle, facing habitat loss due to groundwater overuse and diminishing river flow, has been decreasing the population size and number of sites within their range. We evaluated the presence of the turtle in historical sites in the Rio Sonoyta and used mark-recapture technique during six years to estimate population size in the Papalote reach, one of the most important sites for this subspecies in Mexico. Additionally, we used telemetry techniques to track specific individuals. Our movement study found differences between intermittent and perennial river reaches. Also, turtles in perennial reaches exhibited large areas of use and longer movements, highlighting the impact of flow regime on their behavior. Our findings highlight the need for sustainable water management practices to ensure the survival of the Sonoyta mud turtle and their habitat.