Energetic Payoff of Tool Use for Capuchin Monkeys in the Caatinga: Variation by Season and Habitat Type

Abstract

In this paper, we analyze predictions from the energetic bottleneck and opportunity models to explain the use of stones to crack open encased fruit by capuchins in dry environments. The energetic bottleneck model argues that tool use derives from the need to crack open hard-encased fruits which are key resources during periods of food scarcity. The opportunity model argues that tool use by capuchins derives from simultaneous access to stones and encased fruits. The study was conducted in the Caatinga biome, northeastern Brazil, at two areas where capuchin monkeys (Sapajus libidinosus and Sapajus spp.) regularly use stones to crack open encased fruit of Syagrus cearensis and Manihot dichotoma. Energetic gains were inferred based on the number of tool-use sites used and the mass of encased fruit consumed per month, and compared across seasons and areas occupied by the two groups. For the drier habitat, a significant increase in frequency of tool use (N(dry) = 329 vs. N(wet) = 59) and in the mean monthly mass of fruits consumed in the dry season (mean(dry) = 193g vs. mean(wet) = 13.5 g) offered support for the energetic bottleneck model. However, our inference of low energetic payoffs for tool using individuals (in the drier caatinga habitat from 13 to 193 cal·ind(-1) ·month(-1) and in the wetter caatinga habitat from 805 to 1150 cal·ind(-1) ·month(-1) ) offer support for the opportunity model. Finally, our analyses indicate that consumption of six S. cearensis fruits would equal the daily requirements of capuchins for β-carotene, and the consumption of 1.22 g·day(-1) of M. dichotoma encased fruit or 1.0 g·day(-1) of S. cearensis can supply capuchin's daily requirement of vitamin C. So, specific nutritional requirements may play a role in explaining the continuous consumption of encased fruit and customary use of stones to crack open encased fruit.

Stone Anvil Damage by Wild Bearded Capuchins (Sapajus libidinosus) during Pounding Tool Use: A Field Experiment

“…These data also do not apply to the formation of use-damage on wooden anvils, which require separate study. The main criterion used here to measure anvil damage, percussion pitting, will be less useful in areas with more resistant anvils [27], or in circumstances where particular environments alter anvil characteristics more readily (e.g., the inter-tidal zones exploited by tool-using long-tailed macaques in Thailand [8], [28]). …”

How Different Are Robust and Gracile Capuchin Monkeys? An Argument for the Use ofSapajusandCebus

“…We summarize here some areas where field studies indicate behavioral differences between Cebus and Sapajus , with the caveat that not all species of either of the two types have been well‐studied for any of these behaviors: Tool use:One striking, foraging‐related difference between Cebus and Sapajus is in stone tool use in the wild. It would appear to be ubiquitous across robust capuchin populations in dry habitats (i.e., S. flavius [see Emidio & Ferreira, ]; S. libidinosus [see Emidio & Ferreira, ; Fragaszy et al, ; Ottoni & Izar, ]; S. xanthosternos [see Canale et al, ]) and can occur even in forested areas ( Sapajus spp. [see Ottoni & Mannu, ]), but it has not been recorded in other long‐term studies of Sapajus in rainforest conditions ( S. nigritus in southeast Brazil [Izar et al, ] and Argentina [Di Bitetti, ]; S. apella in Suriname [Gunst et al, ,b], S. macrocephalus in Peru [Janson, ,b] and Colombia [Izawa, ]).…”

“…Our understanding of differences between the gracile and robust capuchin species is limited because the behavior of many capuchin species and subspecies has never been studied. Until now there have been relatively few systematic behavioral comparisons across multiple species, but these kinds of comparisons are included here, that is, C. nigritus versus C. libidinosus for socioecology [Izar et al, ]; gracile versus robust species for anointing behaviors [Lynch Alfaro et al, ]; C. nigritus and C. capucinus for tool use [Garber et al, ]; C. flavius and C. libidinosus for stone tool use [Emidio & Ferreira, ]; and gracile versus robust species for sexual behavior [Matthews, ]. Here we review morphological, biogeographic, ecological, and behavioral differences that distinguish the robust from the gracile capuchin monkeys.…”

Biological and behavioral aspects of Sapajus libidinosus: Review

“…Suas mãos são muito manipulativas e ágeis, sendo os únicos macacos do Novo Mundo capazes de utilizar ferramentas na natureza a fim de facilitar a exploração de recursos (Rocha et al, 1998, Fragaszy & Bard, 1997, Moura & Lee, 2004. Vários trabalhos vêm sendo realizados quanto a essa peculiaridade da espécie em estudo, expondo métodos de resolução de problemas (Silva, 2008, Cardoso, 2013, efeitos do uso de ferramentas no comportamento e bemestar desses animais (Camargo, 2012, Cutrim, 2013; otimização e observação de uso desses materiais em animais de cativeiro e vida livre (Emidio & Ferreira , 2012, Falótico et al, 2017Lessa et al, 2011), e utilização desses métodos de manipulação na brincadeira social dentro do grupo (Carvalho, 2013).…”