Hang on to that tree! Lizards that survived hurricane Maria showed increases in grip strength

Dufour CMS, Donihue CM, Losos JB, Herrel A (2019) Parallel increases in grip strength in two species of Anolis lizards after a major hurricane on Dominica. J Zool jzo.12685. doi: 10.1111/jzo.12685

Header image: Dominican anole, photo by Postdf, Wikimedia Commons

Category 5 hurricanes are real and climate change has led to more frequent and stronger hurricanes

The frequency and intensity of hurricanes  is being affected by rising sea level temperatures. Severe storms of this nature cause catastrophic structural damage, potential loss of human life, and can also significantly affect the structure of natural ecosystems. While past studies have shown that hurricanes are an important source of ecosystem turn-over, scientists worry that changes to the intensity and frequency might lead to widespread extinctions. Because of this, we’re seeing many more studies whose goal is to gather data to evaluate if new hurricane patterns will affect species.   

Hang on to that tree!

In 2017, Hurricane Maria blew through the Carribean, leaving chaos and destruction in its path. Scientists in Dominica, were already studying lizard communities, because of this they had the data to contrast lizards before the hurricane to the survivors after the storm. The research team hypothesized lizards that survived the hurricane would be stronger grippers, meaning that they would be able to resist being blown away from their trees more effectively. Lizards can adhere to surfaces through intermolecular forces created by structures on their feet. Feet with more scales on their toepads (lamellae) and overall larger toepads have greater clinging strength (Figure 1). Before the hurricane, the team measured clinging force by placing a single lizard foot on an acetate sheet and pulling using a force meter. They also measured the lizards body sizes, toepad size, and number of lamellae scales (row of scales on the end of the digit, Figure 1).

Footloose clinging?

The scientists found that contrary to what they expected, lizards that survived the hurricane did not have larger toepads or more lamellae scales (Figure 1). However, lizard clinging strength was twice as much as that of lizards before the hurricane. The scientists were puzzled by these findings. They suggested that perhaps there were changes at the microscopic level which they were not able to measure. In fact, intermolecular forces are produced by microscopic structures inside the lamellea. But, to measure changes in these structures you need an electron microscope which they did not have access to in the field.   

The study of hurricanes

As we prepare for destructive hurricane seasons, studies like these are important to understand if hurricanes can elicit strong evolutionary patterns and how species in general might change as a consequence of the storms. This study shows that being able to resist from getting blown away was an important trait for survivors. The more natural history data we collect of species in the Atlantic the better able we’ll be able to contrast the effect of these storms as they continue to form. This study also connects to humans on a direct level. Small Caribbean islands are likely to face major challenges as the hurricane seasons become more destructive due to climate change. You can help by contacting your representatives and communicating your concerns on climate change and your interest in transitioning towards greener sources of energy. Also consider donating to organizations that provide aid after these types of disasters if you can. 



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Kevin Aviles Rodriguez

I am in the process of completing my PhD in Ecology and Evolutionary Biology at the University of Massachusetts in Boston. I am interested in human environmental changes as natural experiments to test hypothesis about the evolution of animals. Specifically, I study small lizards known as anoles and how living near human households impacts their ecology and behavior. I love fieldwork because often it takes me away from the cold and towards the sunny beachy islands that I love the most.

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