pinecone/core-2020-05-10-deduplication huggingface dataset:
Testing for post-copulatory selection for major histocompatibility complex genotype in a semi-free-ranging primate population.

A large body of evidence suggests that major histocompatibility complex (MHC) genotype influences mate choice. However, few studies have investigated MHC-mediated post-copulatory mate choice under natural, or even semi-natural, conditions. We set out to explore this question in a large semi-free-ranging population of mandrills (Mandrillus sphinx) using MHC-DRB genotypes for 127 parent–offspring triads. First, we showed that offspring MHC heterozygosity correlates positively with parental MHC dissimilarity suggesting that mating among MHC dissimilar mates is efficient in increasing offspring MHC diversity. Second, we compared the haplotypes of the parental dyad with those of the offspring to test whether post-copulatory sexual selection favored offspring with two different MHC haplotypes, more diverse gamete combinations, or greater within-haplotype diversity. Limited statistical power meant that we could only detect medium or large effect sizes. Nevertheless, we found no evidence for selection for heterozygous offspring when parents share a haplotype (large effect size), genetic dissimilarity between parental haplotypes (we could detect an odds ratio of ≥1.86), or within-haplotype diversity (medium-large effect). These findings suggest that comparing parental and offspring haplotypes may be a useful approach to test for post-copulatory selection when matings cannot be observed, as is the case in many study systems. However, it will be extremely difficult to determine conclusively whether post-copulatory selection mechanisms for MHC genotype exist, particularly if the effect sizes are small, due to the difficulty in obtaining a sufficiently large sample
Change point analysis of travel routes reveals novel insights into foraging strategies and cognitive maps of wild baboons

Efficient space use is a critical challenge for animals relying on stationary resources. It is often difficult with purely observational methods to gain unambiguous insight into any ability of primates to manage and process spatial information. Investigating the visible signs of the decision processes underlying space use often leaves open important issues. We applied the change point test [Byrne et al. (2009). Anim Behav 77: 619–631], a statistical tool to objectively determine change points (CPs) in animal travel paths, to investigate to what degree directional changes in our study group's (Papio ursinus) dry season ranging were associated with important resources and prominent landmarks. One-third of directional changes were associated with fruit feeding, 1/3 with traveling, and 1/3 with dry matter feeding, travel feeding and with drinking. When directional changes were associated with traveling, the subsequent directional changes were likely to result in fruit feeding. Fruit feeding mostly occurred at the apex of the day journeys, while drinking, dry matter feeding, and travel feeding often occurred along straight travel segments. The majority of directional changes did not occur in clusters at distinctive locations, but at distances of more than 120 m apart from each other, many of them along prominent landmarks. We conclude that the CPs do not represent nodes or route bends of a network map. Rather, they represent (1) locations where the decision to turn back to their sleeping site was taken, and (2) locations next to important landmarks (changes of slope, car tracks) where slight adjustment of a movement direction was possible. We found no evidence for a Euclidean map and discuss our findings in the light of a network map representation of space.PostprintPeer reviewe
New density estimates of a threatened sifaka species (Propithecus coquereli) in Ankarafantsika National Park

Propithecus coquereli is one of the last sifaka species for which no reliable and extensive density estimates are yet available. Despite its endangered conservation status [IUCN, 2012] and recognition as a flagship species of the northwestern dry forests of Madagascar, its population in its last main refugium, the Ankarafantsika National Park (ANP), is still poorly known. Using line transect distance sampling surveys we estimated population density and abundance in the ANP. Furthermore, we investigated the effects of road, forest edge, river proximity and group size on sighting frequencies, and density estimates. We provide here the first population density estimates throughout the ANP. We found that density varied greatly among surveyed sites (from 5 to ∼100 ind/km2) which could result from significant (negative) effects of road, and forest edge, and/or a (positive) effect of river proximity. Our results also suggest that the population size may be ∼47,000 individuals in the ANP, hinting that the population likely underwent a strong decline in some parts of the Park in recent decades, possibly caused by habitat loss from fires and charcoal production and by poaching. We suggest community-based conservation actions for the largest remaining population of Coquerel's sifaka which will (i) maintain forest connectivity; (ii) implement alternatives to deforestation through charcoal production, logging, and grass fires; (iii) reduce poaching; and (iv) enable long-term monitoring of the population in collaboration with local authorities and researchers.Optimus!Alive- IGC fellowship, FCT fellowship: (SFRH/BD/64875/2009), University of Mahajanga, Groupement de Recherche International (GDRI), "Laboratoire d'Excellence" (LABEX) entitled TULIP (ANR-10-LABX-41), the Rufford Small Grant Foundation grant: (10941-1)
Ecosystem impacts of folivory and frugivory by Japanese macaques in two temperate forests in Yakushima.

Comparing animal consumption to plant primary production provides a means of assessing an animal's impact on the ecosystem and an evaluation of resource limitation. Here, we compared annual fruit and leaf consumption by Japanese macaques (Macaca fuscata) relative to the annual production of these foods in the lowlands and highlands of Yakushima Island, Japan. We estimated consumption by macaques by the direct observation of macaque groups for 1 year in each habitat. We estimated leaf production as the sum of leaf litter fall (corrected for the effect of translocated organic and inorganic matter) and folivory by insects (assumed to be 10%) and by macaques. We estimated fruit production as the sum of fruit litter fall and consumption by birds (estimated by the seed fall) and macaques. The impact of macaque folivory at the community level was negligible relative to production (∼0.04%) compared with folivory by insects (assumed to be 10%); however, for some species, macaque folivory reached up to 10.1% of production. Tree species on which macaques fed did not decline in abundance over 13 years, suggesting that their folivory did not influence tree species dynamics. For the three major fleshy-fruited species in the highland site, macaques consumed a considerable portion of total fruit production (6-40%), rivaling the consumption by birds (32-75%). We conclude that at the community level, macaque folivory was negligible compared with the leaf production, but frugivory was not
Effect of Habitat Quality on Diet Flexibility in Barbary Macaques

International audienceBarbary macaques live in extreme temperate environments characterized by strongly seasonal resource availability. They are mainly terrestrial while foraging, harvesting food from the herbaceous layer. These monkeys are threatened mainly because of anthropogenic habitat degradation. We studied the adaptive capacities of wild groups of Barbary macaques that lived in different cedar forests undergoing varying extents of grazing pressure from domestic livestock. In all three sites, diet varied seasonally. Heavy grazing led to a significant decrease in herbaceous production and species richness. As a consequence, the monkeys' diet in this poor habitat showed a decreased plant species richness. Moreover, it incorporated fewer above‐ground herbaceous resources, and a greater proportion of subterranean resources (especially hypogeous fungi and subterranean invertebrates such as earthworms, eggs and adults of earwigs, and ant's larvae) than the diet of monkeys inhabiting ungrazed forest. Cedar bark, cedar strobiles, earthworms, and earwigs were part of the monkeys' diet only in grazed forest. Monkeys in heavily grazed forest compensated for a lack of herbaceous foods by eating subterranean foods preferentially to tree and shrub products. The foods they consumed take longer to harvest and process than the seeds or leaves consumed by Barbary macaques in less heavily grazed forest habitats. Our results suggest that monkeys do differ in their diets according to the degree of habitat change induced by human activities. They also highlight the dietary flexibility of Barbary macaques as a key element that allows them to cope with degraded habitats. We later compare the dietary adjustments of Barbary macaques facing environmental change to dietary strategies of other macaques and temperate‐zone primates
How the physical properties of food influence its selection by infant Japanese macaques inhabiting a snow-covered area.

Dietary differences exist between infant and adult female non-human primates. These differences are considered to be related to the low ability of infants to bite, handle, and obtain food items. This study aimed to provide a comprehensive examination of how the physical properties of food items (fracture toughness, size, processing, and height) influence food selection by infant primates. In this study, four mother-infant Japanese macaque (Macaca fuscata) pairs were investigated in a snow-covered area during winter. The feeding behavior of both mothers and infants was recorded. The size, need for processing, and height of food items were recorded by direct observation, while the fracture toughness of food items (evaluating the required bite force by incisors) was measured using a rheometer. On average, infants spent 14% less time feeding than their mothers, and there were dietary differences between mothers and infants. Compared to their mothers, infants fed relatively more frequently on food items that were small, at a low position, or that could be consumed without processing. In addition, infants spent less time feeding on food items that were tougher than 2, 000 J/m(2) . Thus, infants fed relatively more frequently on food items that are easy to obtain. This food selection by infants reduced the costs of feeding and allowed them to avoid falling from high trees
Chimpanzees prey on army ants at Seringbara, Nimba Mountains, Guinea: Predation patterns and tool use characteristics

Chimpanzees are renowned for their use of foraging tools in harvesting social insects and some populations use tools to prey on aggressive army ants (Dorylus spp.). Tool use in army ant predation varies across chimpanzee study sites with differences in tool length, harvesting technique, and army ant species targeted. However, surprisingly little is known about the detailed ecology of army ant predation. We studied army ant predation by chimpanzees (Pan troglodytes verus) at the Seringbara study site in the Nimba Mountains, Guinea (West Africa), over 10 years (2003-2013). We investigated chimpanzee selectivity with regards to army ant prey species. We assessed the temporal variation in army ant-feeding and examined whether army ant predation was related to rainfall or ripe fruit availability. Moreover, we examined whether chimpanzees showed selectivity regarding plant species used for tool manufacture, as well as the relationship between tool species preference and tool collection distance. Lastly, we measured tool properties and investigated the use of tool sets and composite tools in army ant predation. Seringbara chimpanzees preyed on one army ant species (D. nigricans) more often than expected based on encounter rates, which may be explained by the overlap in altitudinal distribution between chimpanzees and D. nigricans. Army ant predation was not related to rainfall or fruit availability. Chimpanzees were selective in their choice of tool materials and collected their preferred tool species (Alchornea hirtella) from greater distances than they did other species. Lastly, Seringbara chimpanzees used both tool sets and composite tools (tree perch) in army ant predation. Tool types (dig vs. dip) differed in width and strength, but not length. Tool composites were found at 40% of ant-feeding sites. Our study sheds new light on the ecology of army ant predation and provides novel insights into chimpanzee selection of army ant prey and tool species
Gorillas with white sclera : a naturally occurring variation in a morphological trait linked to social cognitive functions

Funding: Self-funded PhDHuman eye morphology is considered unique among the primates in that humans possess larger width/height ratios (WHR), expose a greater amount of visible sclera (SSI; width of exposed eyeball/width of visible iris), and critically, have a white sclera due to a lack of pigmentation. White sclera in humans amplifies gaze direction, whereas the all-dark eyes of apes are hypothesized to conceal gaze from others. This study examines WHR and SSI in humans (N = 13) and gorillas (N = 85) engaged in direct and averted gazes and introduces a qualitative assessment of sclera color to evaluate variations in sclera pigmentation. The results confirm previous findings that humans possess a larger WHR than gorillas but indicate that humans and gorillas display similar amounts of visible sclera. Additionally, 72% (N = 124) of gorilla eyes in this sample deviated from the assumed all-dark eye condition. This questions whether gaze-camouflage is the primary function of darkened sclera in non-human primates or whether other functional roles can be ascribed to the sclera, light or dark. We argue that white sclera evolved to amplify direct gazes in humans, which would have played a significant role in the development of ostensive communication, which is communication that both shows something and shows the intention to show something. We conclude that the horizontal elongation of the human eye, rather than sclera color, more reliably distinguishes human from great ape eyes, represented here by gorillas.PostprintPeer reviewe
Comparison of feeding behavior between two different-sized groups of Japanese macaques (Macaca fuscata yakui).

Article first published online: 13 MAY 2015Group-living animals face intragroup scramble and intergroup contest competitions. Many studies have shown that larger groups bear the costs of intragroup scramble competition, which negatively affects the reproductive success of females. Unlike most primate species, Japanese macaques in the Yakushima coastal forest show increased reproductive success with group size. However, it remains unclear how group size affects the behavior of macaques. The present study examined the effects of group size on the feeding behavior of Japanese macaques in the Yakushima coastal forest. We investigated 9-13 adult females from two different-sized groups via focal animal sampling during October 2012-August 2013. We compared the feeding behavior, including patch use, between the two groups. The larger group had a larger home range and spent more time feeding, especially on mature leaves. This suggests that intragroup feeding competition should be more intense in the larger group than in the smaller group. The feeding of mature leaves might enable the larger group to increase the number of co-feeding individuals. Contrary to the predictions that the larger group travels longer distances and spends more time moving, the smaller group traveled longer distances, and spent more time moving, although the number of visited patches did not differ between the two groups. The immediate consequences of the loss of inter-group encounters could accumulate as daily travel costs, considering that group size is associated with inter-group dominance and that intergroup aggressive encounters occur frequently in the Yakushima coastal forest. This suggests that the smaller group has increased travel costs as a result of intergroup contest competition, which leads to decline in reproductive success
The functions of non-reproductive mounts among male Barbary macaques (Macaca sylvanus)

Same-sex, non-reproductive mounts have been observed in a number of primate species and in various social contexts. However, the function of non-reproductive mounts is still largely unknown. We aimed to test whether non-reproductive mounts function to assert dominance and as appeasement behavior in male Barbary macaques. We analyzed post-mount behavior in fifty-four macaques belonging to two captive groups at Trentham Monkey Forest in Staffordshire, using 10-minute post-mount/matched-control focal sessions collected either on the mounter or the mountee. In support of the dominance assertion hypothesis, the higher-ranking male within a mounting pair was more likely to be the mounter than the mountee, and to mock bite the lower-ranking male. In support of the appeasement hypothesis, the former mounting partners were more likely to exchange grooming and to have a lower frequency of self-scratching (a measure of social tension) after a non-reproductive mount than in control sessions. Our study indicates that non-reproductive mounts have different and not mutually exclusive functions and can modulate the quality of social interactions among group members. We discuss the possible factors that can affect the occurrence of non-reproductive mounts within and between species
First-time rhesus monkey mothers, and mothers of sons, preferentially engage in face-to-face interactions with infants

Face-to-face interactions between mothers and infants occur in both human and non-human primates, but there is large variability in the occurrence of these behaviors and the reason for this variability remains largely unexplored. Other types of maternal investment have been shown to be dependent on infant sex (e.g. milk production and maternal responsiveness) and maternal experience (e.g. symmetrical communication). Thus, we sought to determine whether variability in face-to-face interactions, that is, mutual gazing (MG), which are hypothesized to be important for later socio-cognitive development, could be explained by these variables. We studied 28 semi-free ranging rhesus monkey (Macaca mulatta) mother-infant dyads (6 primiparous; 12 male infants) born and reared at the Laboratory of Comparative Ethology field station at the NIH Animal Center in Poolesville, MD, across the first 90 postnatal days. Infant sex (i.e. male) was a significant predictor of maternal grooming (β ± SE = 0.359 ± 0.164, Z = 2.19, P = 0.029) whereas both parity (i.e. first time mothers) and infant sex (i.e. male) significantly predicted MG (parity: β ± SE = -0.735 ± 0.223, Z = -3.30, P < 0.001; infant sex: β ± SE = 0.436 ± 0.201, Z = 2.17, P = 0.029). Separation from the mother (outside of arm's reach) was not influenced by parity or infant sex. Together with existing literature, these findings point toward differential maternal investment for sons versus daughters. Mothers may be investing differentially in sons, behaviorally, to ensure their future social competence and thus later reproductive success. Collectively, our findings add to the literature that is beginning to identify early life experiences that may lead to sex differences in neurological and behavioral development.Division of Intramural Research, National Institute of Child Health and Human Developmen
Phylogeny, phylogenetic inference, and cranial evolution in pitheciids and Aotus.

Pitheciids, one of the major radiations of New World monkeys endemic to South and Central America, are distributed in the Amazon and Orinoco basins, and include Callicebus, Cacajao, Chiropotes, and Pithecia. Molecular phylogenetics strongly support pitheciid monophyly, whereas morphological analyses infer a range of phylogenies including a sister relationship between Aotus and Callicebus. We collected geometric morphometric cranial data from pitheciids and Aotus, and used cranial data for distance-based phylogenetic analysis and tests of phylogenetic signal. Phylogenetic analyses of pitheciids were repeated with Lagothrix, Callimico, and Saimiri outgroups for Procrustes shape with and without Aotus based on the whole cranium and six anatomical regions. All phylogenetic signal tests were significant, and tree lengths were shortest and had the least morphological change over the phylogeny for Procrustes residuals from the cranial base and palate. The majority of phylogenetic analyses of Procrustes shape for pitheciids without Aotus supported the molecular phylogeny, and with Aotus included the majority inferred an Aotus–Callicebus clade, although three analyses with Callimico as outgroup supported the molecular phylogeny. The morphological similarity of Aotus and Callicebus is likely a mix of plesiomorphy, allometry, and homoplasy, and future phylogenetic inference of living and extinct platyrrhine taxa should consider the impact of these factors alongside outgroup selection and cranial region
Chimpanzee uses manipulative gaze cues to conceal and reveal information to foraging competitor

This project was funded by the National Institutes of Health's Office of Research Infrastructure Programs base grant to the Yerkes National Primate Research Center—P51OD011132. Financial support for KH was provided by Janet T. Anderson Trust, Scottish Overseas Research Student Award Scheme, and a University of St Andrews School of Psychology studentship. MWC was supported by the FIRST program (NIH/NIGMS (USA) IRACDA grant number K12 GM000680).Tactical deception has been widely reported in primates on a functional basis, but details of behavioral mechanisms are usually unspecified. We tested a pair of chimpanzees (Pan troglodytes) in the informed forager paradigm, in which the subordinate saw the location of hidden food and the dominant did not. We employed cross-correlations to examine temporal contingencies between chimpanzees’ behavior: specifically how the direction of the subordinate’s gaze and movement functioned to manipulate the dominant’s searching behavior through two tactics, withholding and misleading information. In Experiment 1, not only did the informed subordinate tend to stop walking towards a single high value food, but she also refrained from gazing towards it, thus withholding potentially revealing cues from her searching competitor. In a second experiment, in which a moderate value food was hidden in addition to the high value food, whenever the subordinate alternated her gaze between the dominant and the moderate value food, she often paused walking for 5 seconds; this frequently recruited the dominant to the inferior food, functioning as a "decoy". The subordinate flexibly concealed and revealed gaze towards a goal, which suggests that not only can chimpanzees use visual cues to make predictions about behavior, but also that chimpanzees may understand that other individuals can exploit their gaze direction. These results substantiate descriptive reports of how chimpanzees use gaze to manipulate others, and to our knowledge are the first quantitative data to identify behavioral mechanisms of tactical deception.PostprintPeer reviewe