Canopy Openings Reduce Functional Volume in Amphibian Populations of a Neotropical Forest

In the tropical rainforest of Los Tuxtlas, Mexico, we measured five traits—body biomass and volume, cephalic width, mouth width, and snout-vent length—in three amphibian species that exhibit distinct responses to canopy openings: Rheohyla miotympanum, which occurs exclusively beneath the closed canopy; Incilius cavifrons, which is abundant in canopy openings but less frequent under closed canopy conditions; and Pseudoeurycea werleri, which is common under the closed canopy and rare in openings.

No significant differences were observed in the traits of I. cavifrons between open and closed canopy habitats. In P. werleri, only mouth width differed significantly, being greater under the closed canopy. Rheohyla miotympanum, exhibited the lowest functional richness, while I. cavifrons and P. werleri displayed higher values under the closed canopy.