‘Knocking’ on armadillo's door: Uncovering the use of an ecosystem engineer's burrow by the lesser anteater

Armadillos are considered important ecosystem engineers as their burrows can benefit many species. Monitoring burrows with camera traps allows us to obtain relevant biological data on the species that utilize this resource. Our goal in this study was to examine the lesser anteater's (Tamandua tetradactyla) use of giant armadillo (Priodontes maximus) burrows as a first attempt to assess how user species benefit from them. We took camera trap data from a long-term monitoring study (2011–2020) in the Brazilian Pantanal wetland. We then evaluated and classified the frequency and way in which the burrows were used by the individual lesser anteaters. We also assessed the time of entrance and exit from the burrows related to sleep, the period of activity and activity pattern. This species used most monitored burrows, and these were used more than once by the same individuals or by more than one individual at different times. We described four types of uses: inspection of the burrow entrance, inspection of the interior of the burrow, exploratory/resting and sleeping. The lesser anteater was active on average 7 h 42 m per day with a primarily nocturnal activity pattern, which started in the early evening and ended at dawn. This is the first study to evaluate a focal species' use of giant armadillo burrows. Our data suggest that burrows are a valuable resource for the lesser anteater as shelter. Burrow monitoring proved to be effective in obtaining records and key information on the ecology and behaviour of the lesser anteater. New studies may explore this approach to acquire data on other species who frequently use these burrows, including agoutis, tayras, ocelots and coatis.