Dataset Information

Wild capuchin monkeys adjust stone tools according to changing nut properties.

ABSTRACT: Animals foraging in their natural environments need to be proficient at recognizing and responding to changes in food targets that affect accessibility or pose a risk. Wild bearded capuchin monkeys (Sapajus libidinosus) use stone tools to access a variety of nut species, including otherwise inaccessible foods. This study tests whether wild capuchins from Serra da Capivara National Park in Brazil adjust their tool selection when processing cashew (Anacardium spp.) nuts. During the ripening process of cashew nuts, the amount of caustic defensive substance in the nut mesocarp decreases. We conducted field experiments to test whether capuchins adapt their stone hammer selection to changing properties of the target nut, using stones of different weights and two maturation stages of cashew nuts. The results show that although fresh nuts are easier to crack, capuchin monkeys used larger stone tools to open them, which may help the monkeys avoid contact with the caustic hazard in fresh nuts. We demonstrate that capuchin monkeys are actively able to distinguish between the maturation stages within one nut species, and to adapt their foraging behaviour accordingly.

SUBMITTER: Luncz LV

PROVIDER: S-EPMC5021971 | biostudies-literature | 2016 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Wild capuchin monkeys adjust stone tools according to changing nut properties.

Luncz Lydia V LV Falótico Tiago T Pascual-Garrido Alejandra A Corat Clara C Mosley Hannah H Haslam Michael M

Scientific reports 20160914

Animals foraging in their natural environments need to be proficient at recognizing and responding to changes in food targets that affect accessibility or pose a risk. Wild bearded capuchin monkeys (Sapajus libidinosus) use stone tools to access a variety of nut species, including otherwise inaccessible foods. This study tests whether wild capuchins from Serra da Capivara National Park in Brazil adjust their tool selection when processing cashew (Anacardium spp.) nuts. During the ripening proces ...[more]

PMID: 27624672

Similar Datasets

Project description:ObjectivesA hallmark of hominin evolution is the advent and diversification of stone tool use, and biological anthropologists have a particular interest in characterizing tool use behaviors in different hominin species. Robust capuchins, the genus Sapajus, are an excellent convergent model system for understanding tool use evolution, principally in the context of foraging, in terms of how they use stones to process hard fruits. However, most published studies of capuchin tool use in the wild focus on the species Sapajus libidinosus. In order to strengthen comparative analyses, it is important to do research across robust capuchin species to understand tool use capacities and variation across the genus. The first indirect evidence that reported tool use in wild S. xanthosternos was in 2009, but since that time no additional publications have described this behavior for this species. In this study we provide the first complete characterization of tool use in wild S. xanthosternos for two areas within Montes Claros, Minas Gerais state, Brazil: Santa Rosa de Lima district, and Lapa Grande State Park. We compare our findings to the stone tool use characteristics reported in wild Sapajus libidinosus and other capuchin monkey species.Materials and methodsIn monthly surveys from January to September 2018, we walked trails through the two study areas and categorized tool use site characteristics, including anvil area, height, and perimeter; hammer stone weight; and species of fruit utilized. Additionally, we utilized camera traps at high-use sites.ResultsWe describe the tools used by S. xanthosternos at 169 sites clustered in seven Nutcracking Areas, for processing three different species of encased fruit: Macaúba (Acrocomia aculeata), Cansaçao (Cnidoscolus pubescens), and Guariroba (Syagrus oleracea). With camera traps, we directly observed tool use behavior for the first time in this species.DiscussionSapajus xanthosternos displayed tool use patterns very similar to those of S. libidinosus. The main difference was in regards to physical force; in our study, the mean weight of stones used by S. xanthosternos was higher than the mean reported for S. libidinosus at most field sites; however, there was no difference in hammer weight between S. libidinosus and S. xanthosternos when hammering Macaúba. We also registered the heaviest hammer stone for tool use (7.675 kg) known for the robust capuchin genus. It is clear from our study that tool use capacity and characteristics are conserved across the radiation of extant Sapajus, suggesting a possible stone tool use cognitive capacity spanning up to 3.3 million years of diversification within this genus. Unlike stone tool use occurring throughout the year for S. libidinosus, at our study sites S. xanthosternos used nutcracking tools only during the dry season.

Project description:Understanding diet selectivity is a longstanding goal in primate ecology. Deciphering when and why primates consume different resources can provide insights into their nutritional ecology as well as adaptations to food scarcity. Plant pith, the spongy interior of plant stems, is occasionally eaten by primates, but the context is poorly understood. We examine the ecological, mechanical, chemical, and nutritional basis of plant pith selection by a wild, frugivorous-omnivorous primate (Cebus imitator). We test the hypothesis that pith is a fallback food, that is, consumed when fruit is less abundant, and test for differences between plant species from which pith is eaten versus avoided. We collected 3.5 years of capuchin pith consumption data to document dietary species and analyzed "pith patch visits" in relation to fruit availability, visits to fruit patches, and climatic seasonality. We analyzed dietary and non-dietary species for relative pith quantity, mechanical hardness, odor composition, and macronutrient concentrations. Capuchins ate pith from 11 of ~300 plant species common in the dry forest, most commonly Bursera simaruba. We find that pith consumption is not directly related to fruit availability or fruit foraging but occurs most frequently (84% of patch visits) during the months of seasonal transition. Relative to common non-dietary species, dietary pith species have relatively higher pith quantity, have softer outer branches and pith, and contain more terpenoids, a class of bioactive compounds notable for their widespread medicinal properties. Our results suggest that greater pith quantity, lower hardness, and a more complex, terpenoid-rich odor profile contribute to species selectivity; further, as pith is likely to be consistently available throughout the year, the seasonality of pith foraging may point to zoopharmacognosy, as seasonal transitions typically introduce new parasites or pathogens. Our study furthers our understanding of how climatic seasonality impacts primate behavior and sheds new light on food choice by an omnivorous primate.

Dataset Information

Wild capuchin monkeys adjust stone tools according to changing nut properties.

Publications

Wild capuchin monkeys adjust stone tools according to changing nut properties.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets