Uso de ferramentas por macacos-prego associadas a clareiras em manguezal

Abstract

ABSTRACT: The use of tools is observed in several groups of animals, with primates being the most prominent group. Factors such as foraging skills, cognitive ability and social tolerance are likely to be the key to success in some primates. The need to break down encapsulated food due to the scarcity of food resources or the propensity to use it due to the abundance of encapsulated food and the availability of tools, are the two main hypotheses that try to explain the use of tools by primates. The use of tools by capuchin monkeys in nature has been widely studied, mainly in Northeast Brazil. Studies on dry land account for most of this research and more recently efforts have been expanded to mangrove areas. The distribution of breakage sites used by capuchin monkeys is of great relevance for understanding this behavior in primates. This work was developed with the objective of characterizing and estimating the density of anvils and breaking tools present in gaps used by capuchin monkeys in mangroves for crab consumption. Descriptively, we also estimated primate density. This research was carried out in a 33ha natural fragment of mangrove on the banks of the Rio Preguiças, Barreirinhas, State of Maranhão, Brazil. The gaps were located using aerial images obtained by an Unmanned Aerial Vehicle (drone) and confirmed in the field. The area of each clearing was calculated with the software QGis© version 13.10.8. All trunks and tools present were recorded, quantified and their densities calculated. The primate census was carried out on a trail of 868 meters, which was covered 16 times, totaling 13.8 km. An estimated 106 animals were found for the area. In 41 clearings, 192 trunks and 21 tools were recorded. The gaps ranged from 54 m² to 3307 m². Adding an average of 4.6 trunks and 0.51 tools per clearing and a density of 13.1 tools per ha. The study of the use of tools in mangroves can provide important information about the life history, ecology and adaptation of these animals to the different types of habitats where they are inserted.