Anolis stratulus, one of the species studied. Photo by Jerry Husak.

Anolis stratulus, one of the species studied. Photo by Jerry Husak.

Anoles are no strangers to urban environments. In fact, many anole species seem to do just fine in cities. However, they do face a number of different challenges not present in their native environments. One example is the perches on which anoles move. Andrew Battles, a graduate student in Jason Kolbe’s lab at the University of Rhode island, was interested in exploring how the perch use of two anole species differed between natural populations and urban populations, and what that habitat use might do to their running performance. Andrew studied Anolis cristatellus and A. stratulus on Guana Island in the British Virgin Islands to measure perch smoothness/roughness, perch use, and sprinting performance on various perch types.

Lizards were found most often on artificial perches, instead of natural perches, in urban environments. This is interesting, because such artificial substrates tend to be vertically oriented and significantly smoother compared to natural perches like tree branches and trunks. As predicted, lizards ran more slowly on substrates that are smooth and more vertical, and this was most pronounced in the larger male A. cristatellus compared to the smaller female A. cristatellus and both sexes of A. stratulus. Thus, while optimal substrate use might be inclined, rough, natural perches, these anoles are using smoother, more vertical, artificial perches in urban environments. This fits into a theme present at this year’s SICB meeting that animals often move in ways that seem counter-intuitive at first. How such perch decisions might influence fitness remains an open question. Future work will investigate how availability of perches and alternative escape strategies influence perch selection.

Jerry Husak
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