Predator-prey interactions in anurans of the tropical dry forests of the Colombian Caribbean: a functional approach

Anuran–prey selection might be mediated by traits, either by mismatches in
predator and prey traits (preventing interactions) or by predator
selection of prey traits (encouraging interactions). These effect traits
could be summarized in two contrasting foraging strategies: “active” and
“sit‐and‐wait” foragers. We evaluated whether anurans could be classified
into groups of species sharing traits associated with their diet, and what
is the relation between particular effect traits of anurans and their
prey. We collected anurans and identified their stomach contents once
during dry, minor, and major rain seasons in six dry forest sites in the
Colombian Caribbean. For each of the 19 anuran species and 436 prey items,
we registered six effect traits. We applied RLQ and fourth‐corner
methodologies to relate predator and prey traits through their interaction
matrix. Predators were assigned to five groups according to their
differences in locomotion, body shape, proportion of the jaw width, mode
of tongue protrusion, and strata preferred. Regarding preys, species were
assigned to four groups according to their gregariousness, body shape and
hardness, defensive traits, and mobility. Body size of both, predators and
prey, had a minor contribution in the group assignment. We found that
predators using active search target low‐mobility preys, whereas species
using sit‐and‐wait strategy target highly nutritive prey that are
difficult to manipulate. By linking amphibian diet with foraging
strategies, we hope to contribute to the understanding of mechanisms
behind anuran–prey food web patterns and to build more realistic models of
functional response to changing environments.