Buchtel College of Arts and Sciences (BCAS)

Date of Last Revision

2021-09-13 14:48:05



Honors Course


Number of Credits


Degree Name

Bachelor of Science

Date of Expected Graduation

Spring 2020


The digits of anoles and geckos have been extensively investigated for their adhesive pads, which allow them to adhere effectively to smooth surfaces. Many pad-bearing lizards also possess claws, which have been posited as the principal contributor to clinging on rough surfaces. Previous studies have found correlations between habitat use and claw morphology, but whether variation in claw morphology impacts function or not has remained relatively understudied. In addition, it is reasonable to suggest that abrasive wear of the claws may impact clinging ability. I examined both natural and induced variation in the claw morphology of Cuban knight anoles (Anolis equestris) to examine the effects of form and wear on clinging performance on several surfaces of various roughness profiles. I removed the claws of preserved specimens and modified claw morphology using a rotary tool. Claw morphology was quantified via univariate measures typically used in previous work as well as multivariate geometric morphometrics. Results show no effect of claw morphology on clinging on the two smoothest surfaces. However, on the two rougher surfaces, relatively more hooked and long claws induced the highest clinging forces. Additionally, claw wear did not affect induced maximum clinging force. These results suggest that the significance of claw morphology to the clinging ability of lizards may vary with substrate and habitat use. The relative insignificance of claw morphology to clinging on smooth surfaces supports the hypothesis that clinging in lizards with adhesive toe pads is achieved synergistically by both the claw and toe pad across substrates.

Research Sponsor

Peter H. Niewiarowski

First Reader

Ali Dhinojwala

Second Reader

Anthony P. Russell

Honors Faculty Advisor

Brian Bagatto



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