In the fall of 2017, Hurricane Maria ripped across the island of Puerto Rico leaving devastation and destruction in its wake. This caused major changes in the structural environment of forests with unknown consequences for the animals living in them. Kevin Aviles-Rodriguez, a PhD candidate at UMass Boston, wanted to know how the hurricane impacted Anolis cristatellus island wide. Specifically, Kevin was interested in knowing if lizard morphology was altered by the hurricane and how morphological changes differed in urban environments and as time passed post-hurricane.

Here on Anole Annals, we have talked a lot about hurricanes and anoles, most recently related to morphological shifts in Anolis scriptus following hurricane Irma in which Colin Donihue and colleagues observed morphological shifts in limb length and toepad size. Kevin wondered if the same shifts had occurred in A. cristatellus following hurricane Maria, but taking things one step further reasoned that since urban and forest environments differ in structural habitat, that morphological shifts following the hurricane might differ as well.

Hurricane Maria

Hurricane Maria made landfall in the southeast of Puerto Rico and then traversed the island diagonally, causing widespread and lasting destruction.

Kevin resampled the same populations (which I had previously sampled in my own research) at 4 and 11 months post-hurricane. He found that immediately following the hurricane lizards in both urban and forest populations had relatively shorter forelimbs, relatively smaller toepads, and smaller body sizes compared to before the hurricane, and that this effect did not differ between urban and forest populations. These results were contrary to what Kevin expected  since recent research by Donihue et al. found that following hurricane Irma, A. scriptus had relatively longer forelimbs and larger toepads – traits that would increase gripping ability during high winds. Similar to Donihue, however, Kevin also found that the lizards had relatively shorter hindlimbs. As Donihue and colleagues  elegantly demonstrated with their leaf-blower experiments, longer hindlimbs are disadvantageous during hurricanes because they increase the surface area exposed to the wind and act as sails, blowing the lizard more easily off the perch. Interestingly, within 1 year of the hurricane when Kevin again resampled these populations he found that all trait values had increased again to their pre-hurricane values in both urban and forest populations.

Kevin emphasized that the shift in trait means at each time point was small but significant. Importantly, the lack of difference between how forest and urban populations responded (both experienced decreases in mean trait values) suggests that despite structural habitat differences the hurricane imposed similar selective pressures in both habitat types. Kevin continues to dig into morphological variation of urban and forest populations post-hurricane and I look forward to seeing the published results!

Kristin Winchell
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