Dietary habits of the giant armadillo (Priodontes maximus) in the Brazilian wetlands

Abstract

Trophic ecology has major implications for understanding species’ natural history and functional role in ecosystems. This type of information is key to define resource requirements and constraints for conservation planning, especially for threatened specialist species. Here we describe the items that compose the diet of giant armadillos (Priodontes maximus) in the Brazilian wetlands, characterizing their functional role and evaluating if they are true myrmecophages. We sorted 113 fecal samples collected throughout 10 years of monitoring of 29 individuals to identify prey items to the finest possible taxonomic level. Then we estimated the Relative Frequency of Occurrence of each item. The sampling effort was shown to closely represent the expected local prey diversity. Giant armadillos preyed on a diverse array of invertebrates and plants: 23 morphotypes of Isoptera, 50 morphotypes of Hymenoptera, 14 types of seeds, one vertebrate (bone), unidentifiable fragments of Arthropoda, Scarabaeidae fragments, invertebrate eggs, and Acari. All individuals consumed termites (Cornitermes sp. and Nasutermitinae) and plant fragments. There was a high variation on the occurrence of ant morphotypes among samples, most being consumed by few individuals. The most consumed ants were Carebara coeca and Atta vollenweideri, considered crop pests, highlighting armadillo’s importance to society through pest control. Fruits were consumed opportunistically by multiple individuals, likely not incidentally as previously hypothesized, and the role of this large mammal as a seed disperser should be further explored. Although giant armadillo’s diet is more diverse than expected, the high prevalence of termites and ants confirms its myrmecophagous specialization, making them the largest Neotropical specialist insectivore.