Lizards adapt to invasive fire ants, reversing geographical patterns of lizard traits

Date:  November 29, 2018

Source:  Penn State

Some lizards in the eastern U.S. have adapted to invasive fire ants -- which can bite, sting, and kill lizards -- reversing geographical trends in behavioral and physical traits used to avoid predators. A new study describing this reversal appears online on November 29, 2018, in the journal Global Change Biology and reveals that new environmental challenges can override the historical influences that originally determined geographical trends in traits.

"Rapid environmental change, be it from changing climate or the introduction of invasive species, is putting a lot of pressure on native species," said Christopher Thawley, graduate student at Penn State at the time of the study and first author of the paper. "Usually when researchers look at how native species might respond to these kinds of threats, they might measure one characteristic of the animal and at one or a few sites. In this study, we looked at three separate characteristics of eastern fence lizards from thirteen sites spanning a thousand miles and found that these lizards are capable of adapting in a concerted way to meet the threat of invasive fire ants, and in a relatively short time frame."

Some behavioral and physical characteristics within a species change gradually across geographical space, for example animals at one end of the range may have relatively short limbs that, as you move across the range, are longer. These geographical "clines" may be related to changes in temperature, precipitation, or other environmental factors that also change across the geographical range, often with latitude.

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