Cognition, Foraging, and Energetics in Extant and Extinct Primates

Editorial

11 April 2023

Editorial: Cognition, foraging, and energetics in extant and extinct primates

Cécile Garcia

Dora Biro

Karline Janmaat

and

Sandrine Prat

1,630 views

0 citations

Editors

Cécile GARCIA

UMR7206 Eco Anthropologie et Ethnobiologie (EAE)

Dora Biro

University of Oxford

Francine L Dolins

University of Michigan–Dearborn

Karline Janmaat

Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam

Sandrine PRAT

UMR7194 Histoire naturelle de l'Homme préhistorique (HNHP)

Impact

Original Research

08 February 2023

Development of embodied capital: Diet composition, foraging skills, and botanical knowledge of forager children in the Congo Basin

Jorin Veen

, 9 more and

Karline R. L. Janmaat

The embodied capital theory states that the extended juvenile period has enabled human foragers to acquire the complex foraging skills and knowledge needed to obtain food. Yet we lack detailed data on how forager children develop these skills and knowledge. Here, we examine the seasonal diet composition, foraging behavior, and botanical knowledge of Mbendjele BaYaka forager children in the Republic of the Congo. Our data, acquired through long-term observations involving full-day focal follows, show a high level of seasonal fluctuation in diet and foraging activities of BaYaka children, in response to the seasonal availability of their food sources. BaYaka children foraged more than half of the time independent from adults, predominantly collecting and eating fruits, tubers, and seeds. For these most-consumed food types, we found an early onset of specialization of foraging skills in children, similar to the gendered division in foraging in adults. Specifically, children were more likely to eat fruit and seed species when there were more boys and men in the group, and girls were more likely than boys to collect tuber species. In a botanical knowledge test, children were more accurate at identifying plant food species with increasing age, and they used fruits and trunks for species identification, more so than using leaves and barks. These results show how the foraging activities of BaYaka children may facilitate the acquisition of foraging skills and botanical knowledge and provide insights into the development of embodied capital. Additionally, BaYaka children consumed agricultural foods more than forest foods, probably reflecting BaYaka’s transition into a horticultural lifestyle. This change in diet composition may have significant consequences for the cognitive development of BaYaka children.

7,060 views

3 citations

Group size effects on performance across several human studies. The measures of problem-solving performance used across these studies differed. These were, latency to solution (Laughlin et al., 2006), effectiveness (Manners, 1975), accuracy of decisions (Holloman and Hendrick, 1971), and foraging efficiency (Oesch and Dunbar, 2018). In all cases performance increases as small groups increase in size. However, in larger groups performance either decreases above an optimal size, or plateaus, with the benefit of more participants stagnating after a certain group size.

Review

24 October 2022

The primate workplace: Cooperative decision-making in human and non-human primates

Leoma Williams

, 1 more and

Keith Jensen

4,755 views

2 citations

Perspective

03 June 2022

Life in 2.5D: Animal Movement in the Trees

Roi Harel

, 13 more and

Margaret C. Crofoot

A virtual window into a 2.5D world. (A) Integrating three-dimensional animal movement tracks with the mapping of these complex three-dimensional habitats, will enable us to study how animals navigate the branching structures of their arboreal environments. (B) Vertical movement track over time of an arboreal kinkajou (Potos flavus) in reference to ground (brown solid line) tracked on Barro Colorado Island, Panama, and canopy height (green dashed line). GPS data were sampled at 1 Hz and dots represent 1-min median values. The solid black line represents a running median of the height measurements over a 15-min interval. (C) Based on the animal’s horizontal movements we can extract where in the canopy animals move over the course of the day. Spider monkeys (Ateles geoffroyi, red) tend to stay in higher canopy areas, while coatis (Nasua narica, blue), capuchins (Cebus capucinus, purple), and kinkajous (yellow) move through areas with lower canopy heights. The averages (and 95% CI shading) over the active period for four arboreal mammals species: coati (blue, N = 17 individuals), kinkajou (purple, N = 13 individuals), capuchin (yellow, N = 8 individuals), and spider monkey (red, N = 8 individuals) are presented. Each line represents the cumulative average values smoothed over 15-min of the individuals of a single species during the activity time of the individuals. Sources of DEM (digital elevation model) and canopy height data (Havmøller et al., 2021). Coatis sleep high in trees and descend to the ground in the mornings, forage on the ground during the day to return up into the trees at night (Kaufmann, 1962). Kinkajous and capuchins stay within the canopy and are known to only rarely come to the ground. Spider monkeys spend the majority of their day high in the canopy and have the least overall variation in vertical positioning. (D) Sensei-Panama visualization in CAVE2, visualizes animal movement trajectories within a virtual tropical environment, reconstructed from sensor and image data. Animal movements are shown with points connected by lines.

The complex, interconnected, and non-contiguous nature of canopy environments present unique cognitive, locomotor, and sensory challenges to their animal inhabitants. Animal movement through forest canopies is constrained; unlike most aquatic or aerial habitats, the three-dimensional space of a forest canopy is not fully realized or available to the animals within it. Determining how the unique constraints of arboreal habitats shape the ecology and evolution of canopy-dwelling animals is key to fully understanding forest ecosystems. With emerging technologies, there is now the opportunity to quantify and map tree connectivity, and to embed the fine-scale horizontal and vertical position of moving animals into these networks of branching pathways. Integrating detailed multi-dimensional habitat structure and animal movement data will enable us to see the world from the perspective of an arboreal animal. This synthesis will shed light on fundamental aspects of arboreal animals’ cognition and ecology, including how they navigate landscapes of risk and reward and weigh energetic trade-offs, as well as how their environment shapes their spatial cognition and their social dynamics.

5,060 views

7 citations

Results from model M4. Interactions of sex, rank and session number with food type (familiar or novel). Lines represent estimated latency times as a function of session number for novel (red) and familiar (blue) foods and different ranks, indicated by numbers on the right (for novel) or left (for familiar) of each line. The plot on the left concerns females, while the plot on the right concerns males. All other predictors were kept at their sample mean. Line width is proportional to the number of observations for each combination of food type, rank and sex. Lines extend from the minimum to the maximum session number for each combination of food type, rank and sex. Font size of numbers indicating rank is proportional to the number of subjects in each rank in the study sample. Latency time is generally shorter for low-ranking individuals and latency time for novel food decreases markedly from early to late sessions.

Original Research

28 April 2022

Individual Variation in Response to Novel Food in Captive Capuchin Monkeys (Sapajus spp.)

Marialba Ventricelli

, 5 more and

Giulia Sirianni

2,031 views

2 citations

Original Research

22 April 2022

Think Fast!: Vervet Monkeys Assess the Risk of Being Displaced by a Dominant Competitor When Making Foraging Decisions

T. Jean M. Arseneau-Robar

, 3 more and

Julie A. Teichroeb

Within this multi-destination foraging experiment, vervet monkeys at Nabugabo, Uganda needed to make two decisions: which platform to visit first [Decision 1: (A,B,G,H), and which to visit second, Decision 2: (D,E,I,J)]. Decision 1 was a choice between rushing for the platform with the banana (A,G), a strategy which prioritized the preferred-food platform, or (B,H) to start at the nearest corn platform. We attempted to bait platforms such that the preferred food (banana) was not the nearest platform; trials in which the banana was on the nearest platform were censored from the analysis because these trials did not require the monkey to choose between minimizing travel distance and prioritizing preferred food (C). Individuals who chose to visit their nearest corn platform first could then decide if they wanted to (D,I) proceed immediately afterward to the preferred-food platform, or (E,J) travel around the pentagon array in a trajectory that would minimize travel distance, getting the preferred-food when they came to it. Trials in which the platforms were baited such that the preferred-food platform was the second platform encountered when taking the path that minimized travel distance (F) were censored from the analyses because monkeys in these trials did not have to choose between the platform with their preferred food and minimizing travel distance. Note: in box (J) we use the dashed arrow to show the route that a monkey foraging efficiently was expected to take, however, they may not have obtained the rewards on all five platforms if in competition.

Foraging animals need to quickly assess the costs and benefits of different foraging decisions, including resource quantity, quality, preference, ease of access, dispersion, distance, and predation risk. Social animals also need to take social context into account and adapt foraging strategies that maximize net resource intake and minimize contest competition with conspecifics. We used an experimental approach to investigate how social context impacts wild vervet monkey (Chlorocebus pygerythrus) foraging decisions in a multi-destination pentagon array. We baited four platforms with less-preferred corn and one platform with a larger, preferred resource (half banana) that required handling time. We ran over 1,000 trials and found that when monkeys foraged alone, they usually took the path that minimized travel distance but prioritized the preferred-food platform when in competition. However, the foraging strategy chosen by low-ranking individuals depended on the handling skill of the decision maker (i.e., time it would take them to retrieve the banana), the relative rank of their audience members (i.e., who has priority-of-access to resources), and the distance audience members were from the experiment site (i.e., their travel time). When the risk of being displaced by a dominant competitor was low (because they were far away and/or because the decision-maker was skilled in retrieving the banana), low-ranking individuals chose a route that minimized travel costs. Conversely, when the risk of losing food to a dominant competitor was high, decision-makers rushed for the preferred-food platform at the onset of the trial. When the risk of displacement was moderate because a dominant audience member was at least 50 m away, low-ranking individuals partly prioritized the preferred-food platform but took the time to stop for one platform of corn on the way. This strategy increased the total amount of food obtained during the trial. These findings suggest that lower-ranking individuals, who experienced high contest competition at the foraging experiment, calculated the risk of being displaced by a dominant competitor when making foraging decisions. This experiment demonstrates that vervets go through a complex decision-making process that simultaneously considers the profitability of different foraging decisions and their social context.

10,599 views

11 citations

Review

14 March 2022

What Are the “Costs and Benefits” of Meat-Eating in Human Evolution? The Challenging Contribution of Behavioral Ecology to Archeology

Camille Daujeard

and

Sandrine Prat

Despite the omnivorous diet of most human populations, meat foraging gradually increased during the Paleolithic, in parallel with the development of hunting capacities. There is evidence of regular meat consumption by extinct hominins from 2 Ma onward, with the first occurrence prior to 3 Ma in Eastern Africa. The number of sites with cut-marked animal remains and stone tools increased after 2 Ma. In addition, toolkits became increasingly complex, and various, facilitating carcass defleshing and marrow recovery, the removal of quarters of meat to avoid carnivore competition, and allowing the emergence of cooperative (i.e., social) hunting of large herbivores. How can we assess the energy costs and benefits of meat and fat acquisition and consumption for hunter-gatherers in the past, and is it possible to accurately evaluate them? Answering this question would provide a better understanding of extinct hominin land use, food resource management, foraging strategies, and cognitive abilities related to meat and fat acquisition, processing, and consumption. According to the Optimal Foraging Theory (OFT), resources may be chosen primarily on the basis of their efficiency rank in term of calories. But, could other factors, and not only calorific return, prevail in the choice of prey, such as the acquisition of non-food products, like pelts, bone tools or ornaments, or symbolic or traditional uses? Our main goal here is to question the direct application of behavioral ecology data to archeology. For this purpose, we focus on the issue of animal meat and fat consumption in human evolution. We propose a short review of available data from energetics and ethnographic records, and provide examples of several various-sized extant animals, such as elephants, reindeer, or lagomorphs, which were some of the most common preys of Paleolithic hominins.

7,792 views

4 citations