Social tolerance and large group feeding behaviours in response to anthropogenic resource provision in reportedly solitary Neotropical foxes

The Pampas fox (Lycalopex gymnocercus) and South American grey fox (Lycalopex griseus) are both considered solitary species, forming pair bonds and small familial units during the breeding season. In the Argentinian Espinal ecosystem, which forms a large part of the species’ range, extensive agriculture and hunting ranches dominate the landscape. In both settings, carrion is routinely deposited at specified sites for consumption by wildlife, creating microenvironments of high and relatively consistent anthropogenic resource availability. We use continual video monitoring at a carcass disposal site on a hunting ranch in the Argentinian Espinal, and computer vision for automatic animal detection and counting. We show two instances of unusually large groupings and social tolerance by foxes in the genus Lycalopex immediately following carcass deposition. Group behaviour of this kind has implications for mammalian and avian scavenger biodiversity and disease transmission risk in anthropogenically modified ecosystems such as the Espinal and neighbouring Pampas grasslands. Future research is required to investigate the nature of such social grouping, and whether they involve a level of sociality not typically seen in South American canids.