Small lizards more likely to survive hurricanes

Anthony Herrel (UAntwerp) studied population before and after hurricane passage

Hurricanes typically leave death and destruction in their wake. However, research by UAntwerp and other institutes now shows that animals with specific morphological traits are more likely to survive the storm. "We focused on lizards in the Lesser Antilles," says Anthony Herrel. "The animals that survived were smaller and had longer front legs and shorter hind legs."

small lizards more likely to survive hurricanes
Photo: Colin Donihue

A hurricane often has catastrophic consequences for both inhabitants and ecosystems in the local area. Scientists have known for some time that hurricanes lead to increased mortality in animals, but it remained unclear whether this weather phenomenon exerts selection pressure on populations. In other words: do animals survive at random, or are there certain morphological factors at play?

In 2017, a team of scientists including Anthony Herrel – who is affiliated with the CNRS and the National Museum of Natural History in France (Paris) and with the University of Antwerp’s Functional Morphology research group – set out to study Anolis scriptus. This small, tree-dwelling lizard lives on the Turks and Caicos Islands, part of the Northern Lesser Antilles. The researchers mapped out the population’s morphological characteristics.

Larger toepads

"We had only just finished our study when the islands were struck by Hurricane Irma," Herrel remembers. "And two weeks later, Hurricane Maria showed up. My colleagues and I decided to return to the archipelago to see how our research population had weathered both storms. This was a serendipitous but unique opportunity to carry out this kind of study."

The biologists found that, on average, the lizards that had survived were smaller, had longer front legs and shorter hind legs, and also had larger toepads on all four feet. The reptiles use these toepads to cling to trees.

Photo: Colin Donihue

More extreme weather phenomena

Herrel: "It’s the first time that scientists have been able to demonstrate such a direct effect of a hurricane on the morphology of animals. Our research demonstrates that extreme weather conditions, such as hurricanes, can indeed exert direct selection pressure on populations, and in doing so, they can play an important role in biological evolution. This finding is not inconsequential, because extreme weather phenomena will become more frequent in the future as a result of global warming.”

A paper on this research is to be published in the renowned scientific journal Nature.