Trophic structure of native fauna species assemblages in monocultures of a native tree: frogs in avocado orchards in Mexico

The inclusion of monocultures in natural landscapes affects the structure of native species assemblages and modifies biotic interactions, leading to changes in ecosystem dynamics and functioning. In Latin America, avocado crops have been expanding in recent decades but, despite their widespread geographic presence and the crop’s profitability, little is known about the native fauna associated with avocado crops or the biological interactions that occur therein. In Mexico, avocado is a native crop, but its impact on biodiversity is not yet known. We evaluated the trophic structure of the assemblage of anurans in avocado orchards and its relationship to the frogs’ morphological traits and daily activity patterns. Between June and October 2020, we captured frogs in avocado orchards in central-western Mexico and analyzed their stomach contents. The local anuran assemblage has six species, belonging to four different families. Together, they consumed 412 dietary components belonging to 86 families of invertebrates. We detected differences among species regarding the volume of prey consumed, trophic niche breadth, a high degree of diet overlap (60%) and variation in the most important prey items for each frog species. The trophic structure of the frog assemblage was related to the frogs’ size–weight and their daily activity patterns. Our results suggest that avocado crops can host native frog species assemblages, which are made up of habitat–generalist species that, in simplified environments, tend to segregate in their use of trophic resources to reduce interspecific competition and allow for the coexistence of species. This differentiation in the use of trophic resources seems to be facilitated by variations in size–weight and in the daily activity patterns among frog species.