Ant diversity in the diet of giant anteaters, myrmecophaga tridactyla (Pilosa: Myrmecophagidae), in the iberÁ nature reserve, Argentina

Abstract

The giant anteater, Myrmecophaga tridactyla, globally categorized as a vulnerable species, has disappeared in several regions of its original distribution in Argentina. A program to reintroduce the species has been conducted in the Iberá Nature Reserve in Corrientes province since 2006. The diet of released giant anteaters was studied to determine the identity of their prey, and establish whether they have preference for ants or termites or, rather, prefer certain feeding habitats (e. g., open or closed). Twenty two fecal samples were randomly collected during 2008-2013, and heads and mesosomes were recovered. We identified 12 taxa of ants and only one taxon of termites. Observed taxa represent around 80% of the taxa expected to be eaten by anteaters. Camponotus was the most common ant genus, and Acromyrmex and Solenopsis were the numerically most abundant genera. The ant taxa ingested by M. tridactyla were reflective of their natural availablility in the area, suggesting that giant anteaters had no preference for any particular prey. They mainly consumed ant species of the genera Solenopsis, Camponotus and Acromyrmex with conspicuous nests that occur mostly in open habitats of the reserve and not in the most preferred habitat (forest). One possible explanation is that anteaters reduce their foraging search time, and consequently the time they are out in open habitat, so avoiding predation risk and thermal injuries. Thus, conservation of both open and closed habitats would be essential for maintaining the reintroduced populations of giant anteaters.