Summit County Citizens Voice

An Aegean wall lizard on a Greek Island. PHOTO BY JOHANNES FOUFOPOLOUS.

New study shows importance of preserving intact wildlife movement corridors

By Summit Voice

SUMMIT COUNTY — Scientists studying reptile extinctions on Greek islands say their work may help show how global warming will affect plants and animals in the coming centuries. The study also highlights the importance of preserving habitat corridors so plants and animals can migrate in response to climate change, thereby maximizing their chances of survival.

As the climate warmed at the tail end of the last ice age, sea levels rose and formed scores of Aegean islands that had formerly been part of the Greek mainland. At the same time, cool and moist forested areas dwindled as aridity spread through the region. In response to the combined effects of a shifting climate, vegetation changes and ever-decreasing island size, many reptile populations perished.

As researcher Johannes Foufopoulos and his colleagues calculated the population extinction rates of 35 reptile species—assorted lizards, snakes and turtles—from 87 Greek islands in the northeast Mediterranean Sea, they found some striking patterns. In most cases, reptile populations disappeared on the smallest islands first—the places where the habitat choices were most limited. Especially hard hit were “habitat specialist” reptiles that required a narrow range of environmental conditions to survive. In addition, northern-dwelling species that required cool, moist conditions showed some of the highest extinction rates.

The study results appear in the January edition of American Naturalist.

The researchers conclude that a similar pattern of extinctions will emerge at various spots across the globe as the climate warms in the coming decades and centuries. In addition to adapting to a changing climate, plants and animals will be forced to traverse an increasingly fragmented natural landscape.

In many places, small chunks of natural habitat are now surrounded by vast, inhospitable expanses of agricultural and urbanized land, just as those newly formed Aegean islands were surrounded by rising seas thousands of years ago.

“The widespread fragmentation of natural habitats greatly exacerbates the effects of climate change and undermines the ability of species to adapt to the new conditions,” said Foufopoulos, an associate professor at the U-M School of Natural Resources and Environment and the Department of Ecology and Evolutionary Biology.

In addition to Foufopoulos, the paper’s authors are Anthony Ives of the University of Wisconsin and A. Marm Kilpatrick of the University of California, Santa Cruz.

“The lessons learned from the wave of reptile extinctions suggest that if species are to survive the global climate shift already underway, not only do humans have to set significantly more land aside for conservation, but these protected areas will also need to be connected through a network of habitat corridors that allow species migration,” Foufopoulos said.

Over the last several decades, global warming has resulted in a poleward shift in the range of many birds, butterflies and other creatures. This shift to cooler climes—northward in the Northern Hemisphere and southward in the Southern Hemisphere—is expected to continue in the future as organisms seek out places where temperature and moisture levels permit their survival.

Funding for the project was provided through the University of Wisconsin’s Department of Zoology, the University of Michigan, the Princeton Environmental Institute, the Cleveland Dodge Foundation and the U.S. National Science Foundation.

Filed under: Environment, global warming, Summit County Colorado Tagged: | Aegean islands, climate change, global warming, Mediterranean Sea, National Science Foundation, reptile extinctions, Summit County News, University of Michigan