scholarly journals Food hardness and stone tool weight in wild primate nut-cracking

2018 ◽  
Author(s):  
Michael Haslam
Keyword(s):  
Pan Troglodytes ◽  
Macaca Fascicularis ◽  
Primate Species ◽  
Stone Tool ◽  
Pan Troglodytes Verus ◽  
Crack Open ◽  
Hardness Curve ◽  
Species Overlap ◽  
In The Wild ◽  
Nut Cracking

AbstractThis study presents data on average stone tool weights and the hardness of foods processed by the three known stone-tool-using primate species: Burmese long-tailed macaques (Macaca fascicularis aurea), bearded capuchins (Sapajus libidinosus) and Western chimpanzees (Pan troglodytes verus). Each of these primates uses stone hammers to crack open nuts in the wild, making them suitable for inter-species behavioural comparison. This work draws on published results to identify a distinct difference in the tool weight/food hardness curve between chimpanzees and the two monkey taxa, with the latter reaching an asymptote in mean tool weight of just over 1 kg regardless of increasing food hardness. In contrast, chimpanzees rapidly increase their tool weight in response to increasing hardness, selecting average masses over 5 kg to process the hardest nuts. Species overlap in their preference for tools of 0.8-1 kg for opening foods of hardness 2-3 kN, suggesting that this conjunction may represent a primate stone-tool-use optimum.

scholarly journals Naïve orangutans (Pongo abelii & Pongo pygmaeus) individually acquire nut-cracking using hammer tools

2020 ◽  
Author(s):  
Elisa Bandini ◽  
Johannes Grossmann ◽  
Martina Funk ◽  
Anna Albiach Serrano ◽  
Claudio Tennie
Keyword(s):  
Social Learning ◽  
Tool Use ◽  
Pongo Pygmaeus ◽  
Primate Species ◽  
Learning Mechanisms ◽  
Pongo Abelii ◽  
Unique Nature ◽  
In The Wild ◽  
Nut Cracking ◽  
Age Range

AbstractNut-cracking using hammer tools has been argued to be one of the most complex tool-use behaviours observed in non-human animals (henceforth: animals). Recently, even the United Nations Convention on the Conservation of Migratory Species (CMS) recognised the unique nature of chimpanzee nut-cracking by making it the first animal behaviour to be awarded UN-protected status (Picheta, 2020). So far, only chimpanzees, capuchins and macaques have been observed using tools to crack nuts in the wild (Boesch & Boesch, 1990; Gumert, Kluck, & Malaivijitnond, 2009; Ottoni & Mannu, 2001). However, the learning mechanisms behind this behaviour, and the extent of nut-cracking in other primate species are still unknown. The aim of this study was two-fold. First, we aimed to examine whether other great ape species would develop nut-cracking when provided with all the tools and motivation to do so. Second, we wanted to examine the mechanisms behind the emergence of nut-cracking in a naïve sample. Orangutans (Pongo abelii; pygmaeus) have not been observed cracking nuts in the wild, despite having the second most extensive tool-use repertoire of the great apes (after chimpanzees), having the materials for the behaviour in the wild (albeit rarely) and possessing flexible problem-solving capacities. Therefore, orangutans are a valid candidate species for the investigation of the development of nut-cracking. Four nut-cracking-naïve orangutans at Leipzig zoo (Pongo abelii; Mage=16; age range=10-19; 4F; at time of testing) were provided with nuts and hammers but were not demonstrated the nut-cracking behavioural form, in order to control for the role of copying social learning in the acquisition of this behaviour. Additionally, we report data from a previously unpublished study by one of the authors (MF) with eight orangutans housed at Zürich zoo (10 Pongo abelii and two Pongo pygmaeus; Mage=14; age range =2-30; 5F; at time of testing) that followed a similar testing paradigm. Out of the twelve orangutans across both testing institutions, at least four individuals, one from Leipzig (Pongo abelii) and three from Zürich (Pongo abelii; pygmaeus), spontaneously expressed nut-cracking with a wooden hammer. These results suggest that the behavioural form of nut-cracking using hammer tools can emerge in orangutans when required through individual learning combined, in some cases, with non-copying social learning mechanisms.

scholarly journals TT viruses (TTV) of non-human primates and their relationship to the human TTV genotypes

1999 ◽  
Vol 80 (9) ◽  
pp. 2491-2499 ◽  
Author(s):  
Ernst J. Verschoor ◽  
Susan Langenhuijzen ◽  
Jonathan L. Heeney
Keyword(s):  
Pan Troglodytes ◽  
Primate Species ◽  
Pan Troglodytes Schweinfurthii ◽  
Pan Troglodytes Verus ◽  
Tt Virus ◽  
High Incidence ◽  
The Common ◽  
Common Chimpanzee ◽  
Very High ◽  
Human Primate

Sera from eight different non-human primate species, in total 216 samples, were analysed for the presence of TT virus (TTV) sequences. A very high incidence of TTV infection was found in sera from both common chimpanzees and pygmy chimpanzees, 48·8% and 66·7%, respectively. Sequence analysis of PCR fragments from two pygmy chimpanzees and seven common chimpanzees resulted in a total of 14 different TTV sequences. Phylogenetic analysis, including human TTV of all known genotypes, revealed that: (i) TTV from pygmy chimpanzees are closely related to viruses from human genotypes 2 and 3; (ii) TTV sequences obtained from common chimpanzees cluster together with human TTV genotypes 5 and 6, the latter only at the protein level; (iii) TTV from the common chimpanzee subspecies Pan troglodytes verus and Pan troglodytes schweinfurthii cluster together, suggesting an ancient host–pathogen relationship before subspeciation 1·6 million years ago; and (iv) TTV of common and pygmy chimpanzees may have been acquired by these animals in different zoonotic events not longer than 2·5 million years ago.

scholarly journals Landscaping the behavioural ecology of primate stone tool use

2021 ◽  
Author(s):  
Katarina Almeida-Warren ◽  
Tetsuro Matsuzawa ◽  
Susana Carvalho
Keyword(s):  
Tool Use ◽  
Raw Materials ◽  
Stone Tool ◽  
Site Formation ◽  
Behavioural Ecology ◽  
Wild Chimpanzee ◽  
Pan Troglodytes Verus ◽  
Nest Sites ◽  
Frequency Of Use ◽  
Nut Cracking

AbstractEcology is fundamental to the development, transmission, and perpetuity of primate technology. Previous studies on tool site selection have addressed the relevance of targeted resources and raw materials for tools, but few have considered the broader foraging landscape. In this first landscape-scale study of the ecological contexts of wild chimpanzee (Pan troglodytes verus) tool-use, we investigate the conditions required for nut-cracking to occur and persist over time at discrete locations in Bossou (Guinea). We examine this at three levels: selection, frequency of use, and inactivity. We find that, further to the presence of a nut tree and availability of raw materials, abundance of food-providing trees as well as proximity to nest sites were significant predictors of nut-cracking occurrence. This suggests that the spatial distribution of nut-cracking sites is mediated by the broader behavioural landscape and is influenced by non-extractive foraging of predictable resources, as well as non-foraging activities. Additionally, tool availability was greater at sites with higher frequency of nut-cracking and was negatively correlated with site inactivity. Our findings indicate that the technological landscape of the Bossou chimpanzees shares affinities with the ‘favoured places’ model of hominin site formation and provides new insights for reconstructing ancient patterns of landscape use.

scholarly journals Analysis of wild macaque stone tools used to crack oil palm nuts

2018 ◽  
Vol 5 (3) ◽  
pp. 171904 ◽  
Author(s):  
T. Proffitt ◽  
V. L. Luncz ◽  
S. Malaivijitnond ◽  
M. Gumert ◽  
M. S. Svensson ◽  
...  
Keyword(s):  
Oil Palm ◽  
Elaeis Guineensis ◽  
Modern Human ◽  
Primate Species ◽  
Human Populations ◽  
Crack Open ◽  
Number Of Factors ◽  
Use Wear ◽  
Nut Cracking ◽  
Initial Description

The discovery of oil palm ( Elaeis guineensis ) nut-cracking by wild long-tailed macaques ( Macaca fascicularis ) is significant for the study of non-human primate and hominin percussive behaviour. Up until now, only West African chimpanzees ( Pan troglodytes verus ) and modern human populations were known to use stone hammers to crack open this particular hard-shelled palm nut. The addition of non-habituated, wild macaques increases our comparative dataset of primate lithic percussive behaviour focused on this one plant species. Here, we present an initial description of hammerstones used by macaques to crack oil palm nuts, recovered from active nut-cracking locations on Yao Noi Island, Ao Phang Nga National Park, Thailand. We combine a techno-typological approach with microscopic and macroscopic use-wear analysis of percussive damage to characterize the percussive signature of macaque palm oil nut-cracking tools. These artefacts are characterized by a high degree of battering and crushing on most surfaces, which is visible at both macro and microscopic levels. The degree and extent of this damage is a consequence of a dynamic interplay between a number of factors, including anvil morphology and macaque percussive techniques. Beyond the behavioural importance of these artefacts, macaque nut-cracking represents a new target for primate archaeological investigations, and opens new opportunities for comparisons between tool using primate species and with early hominin percussive behaviour, for which nut-cracking has been frequently inferred.

Feeding in fear? How adult male western chimpanzees (Pan troglodytes verus) adjust to predation and savanna habitat pressures

2017 ◽  
Vol 163 (3) ◽  
pp. 480-496 ◽  
Author(s):  
Stacy Lindshield ◽  
Brent J. Danielson ◽  
Jessica M. Rothman ◽  
Jill D. Pruetz
Keyword(s):  
Adult Male ◽  
Pan Troglodytes ◽  
Pan Troglodytes Verus
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