Lizards can become extinct by Climate Change
Dear All,
I came across this interesting piece in The Telegraph. It talks about the impact of climate change on lizards. Some of the species of lizards in the western ghats can become extinct due to increase in temperatures. Sharing it below.
Sabyasachi
Lizards throw up first proof of climate cost
- Global-scale extinction alert
G.S. MUDUR
New Delhi, May 13: The world’s lizards appear doomed to extinction, scientists announced today, unveiling the first evidence of a global-scale extinction process linked to rising temperatures from climate change.
An international research team has discovered that many lizard populations have already vanished in Africa, North and South Americas, Australia and Europe, and India falls in a zone with a super-high risk of extinction.
Scientists believe the disappearance of lizards might have a cascading effect up and down the food chain. Lizards prey on disease-carrying mosquitoes and other insects, and themselves are prey for birds and snakes.
The study has suggested that four per cent of lizard species have gone extinct worldwide since 1975, and 20 per cent of all lizard species will be extinct by 2080. The scientists combined temperature trends and local extinction to catalogue lizards already lost and predict accelerated extinction in the years ahead. These findings will appear in the journal Science on Friday.
While lizards normally bask in the sun, temperatures exceeding their physiological limits could make them retreat into shade rather than risk death from overheating. This could restrict their activity and prevent them from foraging for food.
“We run the risk of losing species even before they are known to science,” said Aaron Bauer, a team member at the Villanova University in the US.
Bauer, who has earlier worked in India’s Western Ghats and the Thar desert, said several lizards in India appear to be at risk, but there were not enough herpetologists in India to study the country’s rich lizard fauna and document the extinction.
“Lizards at higher elevations, including the Western Ghats and the Himalayas, are likely to have (increased) risks of extinction because they will be species that have adapted to cooler temperatures,” Bauer told The Telegraph.
The loss of lizards could lead to a collapse of other species at the upper end of the food chain and an explosion of insect populations, said Barry Sinervo, a professor of ecology at the University of California, Santa Cruz, and lead author of the study. Team member Fausto Mendez de la Cruz in Mexico and his colleagues compared surveys for lizard species at 200 sites in Mexico in 2008 with historical surveys in the 1970s and found that 12 per cent of local populations have gone extinct.
The extinction occurred at sites where temperatures have changed rapidly. The researchers also developed a mathematical model to predict extinction that had already been observed in South America, Europe, Australia as well as Africa.
“None of these are due to habitat loss. These sites are not disturbed in any way, and most of them are in protected areas,” said Sinervo. “We thought we’d see evolution in response to climate change, instead we’re seeing extinction.”
“The preferred body temperature in lizards is highly species-specific — it doesn’t evolve very rapidly,” said Elizabeth Bastiaans, a researcher at the University of California, Santa Cruz, and a co-author of the study. “That’s why we predict that lizards won’t be able to evolve new (temperature) preferences quickly enough to keep up with climate change,” Bastiaans told The Telegraph.
Although scientists have been investigating the potential effects of climate change on plants and animals for years, evidence to support actual extinction on a local or global level has been lacking.
“This is the first research work to offer a model of extinction risk due to global warming, validated with actual extinction events and a physiological model to explain them,” said Martha Calderon-Espinosa, a team member in Columbia.
Although scientists have not yet documented lizard extinction in India, lizards belonging to the family of gekkos which occur in India are expected to experience about 24 per cent extinction by 2050. According to the projections, wall lizards, which also occur in India, are predicted to suffer 46 per cent local extinction of populations by 2080.
Researchers say some of the predicted extinctions may not be preventable.
“Even if we were to stop emitting all carbon dioxide tomorrow, the planet would continue to warm for a while. That makes it unlikely that the extinction that our model predicts can be avoided at this point,” Bastiaans said.
The team that surveyed the lizard extinction in five continents and developed the extinction model for predictions also included researchers from Brazil, Chile, France, South Africa and Australia.
The link to the original article can be found here:
http://www.telegraphindia.com/110051...y_12448299.jsp
