Preventing Tortoise Extinction in the Face of Climate Change
(15.06.2016) As climate change advances, tortoises limited mobility impedes their ability to reach more suitable habitats. A critical conservation task is identifying habitats that will remain suitable given the projected warming and drying at the end of the 21st century.
Researchers in a recent study used a fine-scale approach to address the issue of migration of the federally threatened Agassiz desert tortoise, Gopherus agassizii, in Twentynine Palms, California.
By modeling climate change projected for the end of this century with a three-degree increase in summer temperatures, the authors of an article in the recent issue of Chelonian Conservation and Biology predicted the mobility of the tortoise group, which is slow to find new habitats in the face of depleted resources.
The article shows a means to project future suitable habitats and how to maximize tortoise survivorship in the face of environmental shifts.
In the article, the researchers project that maximum end-of-century summer temperatures could reduce tortoise habitat area by 55 percent in parts of the Mojave Desert. Thankfully, the authors found that a substantial portion of the climate-shifted area would overlap with current tortoise habitat. This overlap would serve as climate refugia, or sanctuary, to provide a future safe haven for these threatened animals.
These climate refugia offer tortoises the best opportunity to survive into the future, and so represent our highest conservation priorities, said lead author Dr. Cameron Barrows. Given the importance of these areas for the species, the researchers noted that efforts should be made to limit human expansion into these habitats.
Since climate change affects humans and turtles alike, the situation of Agassiz desert tortoise provides a compelling example of how current species management practices are being developed. Considering the challenges of maintaining biodiversity as climate change progresses, the approach outlined in the study is one that perhaps can help stave off species extinctions on large and small scales.
Full text of the article, Identifying Climate Refugia: A Framework to Inform Conservation Strategies for Agassizs Desert Tortoise in a Warmer Future, Chelonian Conservation and Biology, Vol. 15, No. 1, 2016, is available at: http://www.chelonianjournals.org/doi/full/10.2744/CCB-1157.1.