Relationship between body size and niche breadth in frogs of the family Leptodactylidae in two localities of the department of Casanare, Colombia

Abstract

This study evaluated the relationship between body size and niche breadth in three microhabitat resources (substrate, vertical position, and horizontal position) used by leptodactylids in two localities of Casanare, Colombia. Sampling was conducted in March 2021 through visual encounter surveys, with a total effort of 144 hours. For each individual, snout–vent length and the use of each resource state were recorded. The mean body size of each species and niche breadth were calculated using the standardized Levins index, and their association was tested through Pearson and Spearman correlation analyses. The highest proportion of individuals in both localities used the vertical position on the exposed surface of the substrate, horizontal position I, and the substrates bare soil and leaf litter. Leptodactylus latrans and Physalaemus fischeri showed the highest niche breadth values for vertical and horizontal position, respectively, whereas the other species exhibited reduced breadth. No relationship was found between body size and niche breadth in the three resources evaluated. These results suggest that microhabitat use patterns may be more related to factors such as seasonality, resource availability, and the specific physiological and reproductive requirements of each species, highlighting the need to increase sampling effort and to integrate additional factors to better understand the determinants of niche breadth in this family.