A number of North American turtle species have been forced to seek new habitats as a result of climate change, according to a study which looked at data from over 300 published studies on 59 turtle species.
The study, published in PLoS ONE, found that just one degree of either warming or cooling leads turtles to shift their geographic ranges an average of 45 miles. These shifts have resulted in some turtle species finding appropriate new habitats, while others have been pushed into unsuitable areas.
“By studying how turtles responded to these climate cycles, we can learn about regional differences of the impact of climate change, how climate change differently impacts species, and how climate has influenced evolution,” said Michelle Lawing, a postdoctoral fellow at the National Institute for Mathematical and Biological Synthesis and co-lead author of the study.
The PLoS ONE study is the first to “comprehensively [integrate] all available information for the majority of all North American turtle species,” said study co-lead author Dennis Rödder, curator for herpetology at the Leibniz-Institute for Terrestrial Biodiversity Research at the Zoologisches Forschungsmuseum Alexander Koenig in Germany. The 300-plus published studies integrated into this new study cover turtle physiology, genetics and fossils. Researchers created models incorporating 320,000 years of climate change cycles, a time period during which the planet went through great temperature variations and three glacial-interglacial cycles.
The turtles species hit the hardest by climate change were found to be those in the deserts, lakes and temperate forests and grasslands in the Central and Eastern United States. Turtle species along the Pacific Coast were more resilient to climate change, as were turtles in the tropics, Mexico and the Western United States.
While turtles have been coping with climate change for hundreds of thousands of years, study co-author David Polly of Indiana University said that it isn’t as easy for today’s turtles to just pick up and go somewhere else.
“In the past, turtles have coped with climate change by shifting their geographic ranges to areas with more compatible climates,” said Polly. “However, it is more difficult for modern turtles to do that with today’s managed waterways and agricultural and urban landscapes.”
Anders Rhodin, chair of the Tortoise and Freshwater Turtle Specialist Group at the International Union for Conservation of Nature, said in 2011 that half of turtle species worldwide are threatened with extinction.
Source: Josh Lieberman | International Science Times