Year: 2025
Type: article
Abstract: The adhesive toepads of frogs are a key morphological adaptation that enables them to exploit vertical and overhanging surfaces. In all extant frog species, toepads attach to the substrate via a mucus layer that increases surface area at the micro- and nanoscale and generates adhesive forces (Hanna & Barnes, 1991; Langowski et al., 2018). The effectiveness of this mechanism relies on maximizing the contact area between the toepads and the substrate. Paradoxically, we observed frogs of five species across five families and three continents exhibiting digital hyperextension—lifting their toepads away from the surface and effectively negating adhesion (Figure 1). Given the established importance of toepads for attachment, the simultaneous presence of digital hyperextension that lifts the toepads from the surface appears paradoxical, and so the functional significance of digital hyperextension warrants further investigation. Here, we briefly outline the mechanisms through which frogs achieve adhesion to their substrate, we document five instances of digital hyperextension in the field which effectively negate adhesion, show that this behavior is present in anurans across a broad phylogenetic and geographic range (Figure 1), and provide several hypotheses to explain this behavior and how best to test them.
Source: Ecology
DOI: 10.1002/ecy.70272
Institutions: The University of Adelaide, James Cook University
Language: English
Subfield: Global and Planetary Change
Field: Environmental Science
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W4417153600