Lizard extinctions blamed on global warming
In a study to be published Friday in the journal Science, an international team of biologists reports that in more than one-tenth of the places in Mexico where lizards flourished in 1975 the reptiles now cannot be found. The researchers predict that by 2080 about 40 percent of local lizard populations worldwide will have died off, and 20 percent of lizard species will be extinct.
The reason for the huge die-off appears to be rising temperatures. But it isn't heat that is killing the lizards directly.
Instead, global warming appears to be lengthening the period of the day when lizards must seek shelter or run the risk of heat stroke. In the breeding season, that sheltering period is now so long that females of many species are unable to eat enough food to produce eggs and offspring.
Springs that start earlier and are warmer than they once were have been noted in many regions of the world in the past three decades. The new study suggests that phenomenon may be far more important for the survival of some animals than peak summer temperatures, which have risen only slightly, said Barry Sinervo, an evolutionary biologist at the University of California in Santa Cruz who headed the 26-person research team.