Some lizards can go to 5.5° C, 4 degrees colder than thought, before they can’t move any more
After the coldest night in south Florida in a decade, lizards were dropping out of palm trees, landing legs up. The scientists who raced to investigate the fallen reptiles have now found that, despite such graceless falls, some of these tropical, cold-blooded creatures are actually more resilient to cold than previously thought.Although climate change is expected to include gradual warming globally, scientists think that extreme events such as heat waves, cold snaps, droughts and torrential downpours could also grow in number and strength over time.
The idea for the new study was born after evolutionary ecologist James Stroud received a photo of a roughly 60-centimeter-long iguana on its back on a sidewalk from a friend in Key Biscayne, an island town south of Miami. The previous night, temperatures dropped to just under 4.4° Celsius (40° Fahrenheit).
“When air temperatures drop below a critical limit, lizards lose the ability to move,” says Stroud, of Washington University in St. Louis. Lizards that sleep in trees “may lose their grip.” Stunned lizards on the ground are likely easy prey for predators, he notes.
