This is an almost unedited press release from PhysOrg.com.
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A sample group of Aegean wall lizards
was
captured during field work on one
of the Greek study islands.
Credit: Johannes
Foufopoulos
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A wave of reptile extinctions on
the Greek islands over the past 15,000 years may offer a preview of the way
plants and animals will respond as the world rapidly warms due to human-caused
climate change, according to a University of Michigan ecologist and his
colleagues.
The Greek island extinctions also highlight the critical importance of
preserving habitat corridors that will enable plants and animals to 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.
To gain a clearer understanding of the past consequences of climate change,
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. The calculated extinction
rates were based on the modern-day presence or absence of each species on
islands that were connected to the mainland during the last ice age.
Foufopoulos and his colleagues found a striking pattern to the island
extinctions. 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.
Citation
Foufopoulos,
J., A. Marm Kilpatrick, and A. R. Ives. 2011. Climate
Change and Elevated Extinction Rates of Reptiles from Mediterranean Islands. The American Naturalist 177:19-129.
Labels: climate change, lizards, Pliestocene