Stepping stones facilitate river crossings by Myrmecophaga tridactyla in the north-eastern Brazilian Amazon

The ability of giant anteaters (Myrmecophaga tridactyla) to swim has been documented in the literature, but observations in the wild are scarce. Here, we document an observation recorded on 26 September 2017 when an adult M. tridactyla was seen crossing a 150 m wide river in the north-eastern Amazon, Brazil. The individual successfully crossed the river using a combination of swimming and walking over large rocks that were exposed during the dry season. It appears likely that the individual chose the river section with large rocks to help it to cross the river. We discuss that rocks may play a role in the facilitation of river crossings by giant anteaters and other mammals, especially during the dry season when the river level is lower, thus creating more rapids and more exposed rocks that can be utilized.