Graduation Year


Document Type




Degree Name

Doctor of Philosophy (Ph.D.)

Degree Granting Department

Biology (Integrative Biology)

Major Professor

Stephen M. Deban, Ph.D.

Committee Member

Philip J. Motta, Ph.D.

Committee Member

Bradford J. Gemmell, Ph.D.

Committee Member

David W. Murphy, Ph.D.


adhesion, wetness, mucus, performance, roughness


The ability to cling to and climb on inclined, vertical, and inverted surfaces gives animals access to additional shelter and food and may provide refuge from unsuitable temperature and moisture conditions or escape from ground-dwelling predators. Salamanders have been shown to cling to surfaces and engage in climbing behavior, but their maximum clinging capability and mechanisms of attachment are not well understood. While some arboreal salamanders possess prehensile tails, salamanders lack many morphological adaptations for attachment, such as claws, toe pads, and fibrillar adhesive pads. Maximum cling performance and surface area of attachment were measured, and the adhesive capability of salamander mucus was quantified to investigate how behavior and morphology interact with surface properties to determine cling performance. This study found that many species of salamanders are capable of clinging fully inverted on smooth, challenging surfaces using the viscous and adhesive properties of their mucus. Body size and surface area of attachment impact cling performance, in conjunction with behavior and surface properties such as surface roughness, wetness, and porosity. Variation in area of attachment and characteristic clinging posture have significant effects on maximum cling performance. Surface porosity has no effect on maximum cling angle, demonstrating that suction does not contribute to salamander cling performance. On roughened surfaces, salamanders can engage in gripping behavior which improves attachment performance. Wetted surfaces can enhance cling performance through improved contact surface at the substrate-mucus-skin interface. Salamander cling performance is complex, resulting from the interaction of physical properties of the substrate and mucus layer as well as animal morphology and behavior.

Included in

Biomechanics Commons