The use of stone tool sites to estimate the home range of blonde capuchin monkeys in the Caatinga dry forest.

The home range represents the space in which individuals of a determined species carry out their essential activities and is influenced by ecological and behavioural factors. Accurate estimates of a given home range are essential for understanding the spatial requirements of a species and for developing effective conservation strategies. Therefore, this study aimed to estimate and characterise the minimum home range of a group of blonde capuchin monkeys (Sapajus flavius) in a Caatinga dry forest in northeastern Brazil, using tool-use sites as spatial indicators. Between November 2023 and December 2024, 370 stone tool sites with evidence of recurrent use (presence of food remains) were recorded and georeferenced using handheld GPS, posteriorly confirmed by camera traps. Based on these stone tool sites, the home range of the group was delineated using the minimum convex polygon method with 100% of the locations. The size of the minimum home range was 53.7 ha; the majority of the home range consisted of Savannah Formations (67.7%, 36.35 ha), followed by anthropogenic areas (27.6%, 14.9 ha). We conclude that lithic sites can serve as an alternative indicator for spatial estimates of blonde capuchin home ranges in contexts where direct observation is difficult. Furthermore, human-modified areas in the home range may reduce the availability of food resources and consequently, stone tool use sites. Our results provide the first home range estimate for blonde capuchins in the Caatinga dry forest and highlight the need to improve habitat quality.