The socio-spatial ecology of giant anteaters in the Brazilian Cerrado

Abstract

Movement is a key component of an animals life history. While there are numerous factors that influence movement, there is an inherent link between a species social ecology and its movement ecology. Despite this inherent relationship, the socio-spatial ecology of many species remains unknown, hampering ecological theory and conservation alike. Here, we use fine-scale GPS location data and continuous-time stochastic processes to study the socio-spatial ecology of 23 giant anteaters (Myrmecophaga tridactyla) in the Brazilian Cerrado. We found that individuals occupied stable home ranges with a mean area of 5.45 km2 with males having significantly larger home ranges than females. The average amount of home-range overlap was low (0.20, n = 121 dyads), with no evidence that giant anteater home ranges were structured based on territorial, mate guarding, nor other social behaviour. We also identified a total of 2774 encounter events. Interestingly, both female-male and male-male dyads had significantly more encounters than female-female dyads, with two pronounced seasonal peaks in female-male encounters. Though encounters occurred frequently, associations between dyads were generally weak and there was little evidence of any correlated movement (mean amount of total correlation = 0.01). Collectively, these findings suggest giant anteaters are a solitary and largely asocial species that readily share space with conspecifics. Despite their present capacity to share space, the combined pressures of being condensed into smaller areas and decreased food availability due to increased pesticide use may see behavioural changes radiating throughout the population. Our study provides insight into heretofore unknown aspects of the socio-spatial ecology of this iconic, but understudied species, as well as crucial information for proactive area-based management. Ultimately, these findings contribute towards sustainable development while potentially maintaining the ecological integrity of giant anteaters and their habitats.