Ecomorphology of Anurans: The Challenge of Ecological Categories and Locomotor Modes

Ecomorphology examines how species' morphology adapt to their environments, providing insights into biodiversity and evolution. This field relies on three main components: a morphological matrix, an ecological matrix, and phylogeny. A major challenge in contemporary anuran ecomorphology is constructing the ecological matrix, as categorizing species' ecological roles lacks a standardized methodology, leading to inconsistencies across studies and complicating comparisons. In this study, we discuss the challenges of systematizing criteria for constructing the ecological matrix in anurans. To this end, we conducted a literature search, focusing on studies that consider microhabitats as ecological categories and locomotor abilities, using relevant keywords to the topic. A total of 31 studies from the last 46 years were selected for analysis, and information was extracted on the following aspects: analyzed species; microhabitat and locomotor mode categories; and whether or not own criteria for assigning ecological categories (i.e., microhabitat and locomotor modes) were specified. The analyzed studies reveal a high degree of consistency in the assignment of ecological categories for microhabitat classification but not for locomotor modes designation. The main discrepancies occur in the burrowing and/or fossorial categories, as well as climbing. Interestingly, these categories appear both as microhabitats and as locomotor modes. Key criteria include direct field observations and assignments based on primary literature sources. The variability in category assignments and data collection criteria underscores the need to develop more standardized protocols for ecological categorization to improve the accuracy and reproducibility of ecomorphological studies.