October 9, 2013
Turtles On The Run As Habitats Shift And Shrink
[ Watch the Video: North American Turtles Face Shrinking Habitats ]
Brett Smith for redOrbit.com - Your Universe Online
As climate change progresses, it threatens to push species out of their current habitats and into unfamiliar territories. According to a new research review in the journal PLOS ONE, turtle populations face an uncertain future and could be stressed or severely threatened by climate change-induced displacement.
In the study, researchers looked at 59 species of North American turtles using data from over 300 published studies on turtle physiology and genetics, fossils, and models showing the reptiles’ response to climate change over the last 320 thousand years. During the time period covered by the review, the planet passed through three significant climate-change cycles.
The research team discovered that the centers of the turtles' ranges moved an average of 45 miles for each degree of temperature change. While some species were able to locate a wide-ranging suitable habitat, other species’ ranges shrunk considerably.
"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 study author Michelle Lawing, a postdoctoral fellow at the National Institute for Mathematical and Biological Synthesis.
[ Watch The Video: Hot Turtle Homes ]
The team’s findings are important for estimating future extinction risks that could be caused by climate change, according to study author Dennis Rödder, a curator for herpetology at the Leibniz-Institute for Terrestrial Biodiversity Research in Bonn, Germany.
"This study, which for the first time comprehensively integrates all available information for the majority of all North American turtle species, provides profound evidence of how global warming will affect the genetic architecture of the turtles," Rödder said.
The research review indicated that the rate of modern climate change is much faster than turtles' ability to adapt and evolve with the changes. The scientists said they expect the reptiles will have to change their geographic ranges to keep up with the shifting climate. However, habitable regions for the turtles are at a premium.
"In the past, turtles have coped with climate change by shifting their geographic ranges to areas with more compatible climates. However, it is more difficult for modern turtles to do that with today's managed waterways and agricultural and urban landscapes," said co-author David Polly, professor of geological sciences at Indiana University.
Over half of Earth’s approximately 330 turtle and tortoise species are in danger of extinction due to illegal trade and habitat loss, according to the International Union for Conservation of Nature (IUCN). The reptiles are at a much higher extinction risk than numerous other vertebrates, rivaled only by primates. Many of the most threatened turtles and tortoises are found in Asia.
While people may be tempted to take turtles as pets, conservation groups advice against it. Many turtles are stressed by over-handling and require more care than people may think. Some box turtles will wander fruitlessly in search of their original home until they die if removed from their habitat.
If people do want a pet box turtle, experts recommend getting a captive-bred turtle from a reputable dealer.