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Oelze VM, O'Neal I, Wittig RM, Kupczik K, Schulz-Kornas E, Hohmann G. A skew in poo: Biases in primate fecal isotope analysis and recommendations for standardized sample preparation. Am J Primatol 2023; 85:e23436. [PMID: 36239010 DOI: 10.1002/ajp.23436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 08/29/2022] [Accepted: 09/05/2022] [Indexed: 01/05/2023]
Abstract
Feces are a treasure trove in the study of animal behavior and ecology. Stable carbon and nitrogen isotope analysis allows to assess the dietary niches of elusive primate species and primate breastfeeding behavior. However, some fecal isotope data may unwillingly be biased toward the isotope ratios of undigested plant matter, requiring more consistent sample preparation protocols. We assess the impact of this potential data skew in 114 fecal samples of wild bonobos (Pan paniscus) by measuring the isotope differences (Δ13 C, Δ15 N) between bulk fecal samples containing larger particles (>1 mm) and filtered samples containing only small particles (<1 mm). We assess the influence of fecal carbon and nitrogen content (ΔC:N) and sample donor age (subadult, adult) on the resulting Δ13 C, Δ15 N values (n = 228). Additionally, we measure the isotope ratios in three systematically sieved fecal samples of chimpanzees (Pan troglodytes verus), with particle sizes ranging from 20 μm to 8 mm (n = 30). We found differences in fecal carbon and nitrogen content, with the smaller fecal fraction containing more nitrogen on average. While the Δ13 C values were small and not affected by age or ΔC:N, the Δ15 N values were significantly influenced by fecal ΔC:N, possibly resulting from the differing proportions of undigested plant macroparticles. Significant relationships between carbon stable isotope ratios (δ13 C) values and %C in large fecal fractions of both age groups corroborated this assessment. Δ15 N values were significantly larger in adults than subadults, which should be of concern in isotope studies comparing adult females with infants to assess breastfeeding. We found a random variation of up to 3.0‰ in δ13 C and 2.0‰ in nitrogen stable isotope ratios within the chimpanzee fecal samples separated by particle sizes. We show that particle size influences isotope ratios and propose a simple, cost-effective filtration method for primate feces to exclude larger undigested food particles from the analysis, which can easily be adopted by labs worldwide.
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Affiliation(s)
- Vicky M Oelze
- Anthropology Department, University of California, Santa Cruz, Santa Cruz, California, USA
| | - Isabella O'Neal
- Anthropology Department, University of California, Santa Cruz, Santa Cruz, California, USA
| | - Roman M Wittig
- Department of Human Behavior, Max Planck Institute for Evolutionary Anthropology, Ecology and Culture, Leipzig, Germany.,Institute for Cognitive Sciences, CNRS UMR5229 University Claude Bernard Lyon 1, Bron, France
| | - Kornelius Kupczik
- Department of Anthropology, Faculty of Social Sciences, University of Chile, Ñuñoa, Santiago de Chile, Chile.,Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Ellen Schulz-Kornas
- Department of Cariology, Endodontology and Periodontology, University of Leipzig, Leipzig, Germany
| | - Gottfried Hohmann
- Department of Human Behavior, Max Planck Institute for Evolutionary Anthropology, Ecology and Culture, Leipzig, Germany.,Max-Planck-Institute of Animal Behavior, Konstanz, Germany
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Lindshield S, Hernandez-Aguilar RA, Korstjens AH, Marchant LF, Narat V, Ndiaye PI, Ogawa H, Piel AK, Pruetz JD, Stewart FA, van Leeuwen KL, Wessling EG, Yoshikawa M. Chimpanzees (Pan troglodytes) in savanna landscapes. Evol Anthropol 2021; 30:399-420. [PMID: 34542218 DOI: 10.1002/evan.21924] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 12/17/2020] [Accepted: 07/29/2021] [Indexed: 12/22/2022]
Abstract
Chimpanzees (Pan troglodytes) are the only great apes that inhabit hot, dry, and open savannas. We review the environmental pressures of savannas on chimpanzees, such as food and water scarcity, and the evidence for chimpanzees' behavioral responses to these landscapes. In our analysis, savannas were generally associated with low chimpanzee population densities and large home ranges. In addition, thermoregulatory behaviors that likely reduce hyperthermia risk, such as cave use, were frequently observed in the hottest and driest savanna landscapes. We hypothesize that such responses are evidence of a "savanna landscape effect" in chimpanzees and offer pathways for future research to understand its evolutionary processes and mechanisms. We conclude by discussing the significance of research on savanna chimpanzees to modeling the evolution of early hominin traits and informing conservation programs for these endangered apes.
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Affiliation(s)
- Stacy Lindshield
- Department of Anthropology, Purdue University, West Lafayette, Indiana, USA
| | - R Adriana Hernandez-Aguilar
- Department of Social Psychology and Quantitative Psychology, Faculty of Psychology, University of Barcelona, Barcelona, Spain.,Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Amanda H Korstjens
- Life and Environmental Sciences Department, Bournemouth University, Talbot Campus, Poole, UK
| | | | - Victor Narat
- CNRS/MNHN/Paris Diderot, UMR 7206 Eco-anthropology, Paris, France
| | - Papa Ibnou Ndiaye
- Département de Biologie Animale, Faculté des Sciences et Techniques, Université Cheikh Anta Diop de Dakar, Dakar, Senegal
| | - Hideshi Ogawa
- School of International Liberal Studies, Chukyo University, Toyota, Aichi, Japan
| | - Alex K Piel
- Department of Anthropology, University College London, London, UK
| | - Jill D Pruetz
- Department of Anthropology, Texas State University, San Marcos, Texas, USA
| | - Fiona A Stewart
- Department of Anthropology, University College London, London, UK.,School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, UK
| | - Kelly L van Leeuwen
- Department of Life and Environmental Sciences, Bournemouth University, Talbot Campus, Poole, UK
| | - Erin G Wessling
- Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Midori Yoshikawa
- Department of Zoology, National Museum of Nature and Science, Ibaraki, Tokyo, Japan
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Tsutaya T, Ogawa NO, Nomura T, Shimizu M, Ohkouchi N, Kuze N. Carbon and nitrogen stable isotopic offsets between diet and hair/feces in captive orangutans. Primates 2021; 62:945-954. [PMID: 34415484 DOI: 10.1007/s10329-021-00940-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 08/02/2021] [Indexed: 10/20/2022]
Abstract
Estimating stable isotopic offset values is crucial for dietary reconstructions. Although research into stable isotope ecology of wild nonhuman primates is increasing overall, only a minority of studies involve laboratory experiments. This study is the first to report the carbon and nitrogen stable isotopic offset values in hair and feces of orangutans. During an experiment lasting 1 week, the weight of each consumed food item was recorded for each of six captive Bornean orangutan (Pongo pygmaeus) individuals. The food, hair, and fecal samples were collected for a few days, and their stable carbon and nitrogen isotope ratios were measured using an elemental analyzer/isotope ratio mass spectrometer. Subsamples of feces were treated with ethanol during the preservation process. Monte Carlo analyses showed that the 95% confidence intervals (CIs) of the carbon and nitrogen offset values between hair and diet were +0.9‰ to +3.9‰ and +2.3‰ to +4.5‰, respectively. The 95% CIs of the carbon and nitrogen offset values between feces and diet were -3.7‰ to -0.9‰ and +0.3‰ to +2.7‰, respectively. The effect of ethanol treatment on the stable isotope ratios of feces was unclear and inconclusive. The computed offset values of hair in captive orangutans are similar to those reported in other nonhuman primates, although those of feces showed greater interspecies variations. The offset values estimated in this study contribute to isotopic studies into the feeding ecology of free-ranging orangutans who are critically endangered in most wild settings.
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Affiliation(s)
- Takumi Tsutaya
- Department of Evolutionary Studies of Biosystems, the Graduate University for Advanced Studies, Shonan Village, Hayama, Kanagawa, 240-0193, Japan. .,Japan Agency for Marine-Earth Science and Technology, Biogeochemistry Research Center, Research Institute for Marine Resources Utilization, Natsushima 2-15, Yokosuka, Kanagawa, 237-0061, Japan.
| | - Nanako O Ogawa
- Japan Agency for Marine-Earth Science and Technology, Biogeochemistry Research Center, Research Institute for Marine Resources Utilization, Natsushima 2-15, Yokosuka, Kanagawa, 237-0061, Japan
| | - Toshiya Nomura
- Tama Zoological Park, Hodokubo 7-1-1, Hino, Tokyo, 191-0042, Japan
| | - Mika Shimizu
- Tama Zoological Park, Hodokubo 7-1-1, Hino, Tokyo, 191-0042, Japan.,Present address: Ikimonosha, Maya 714, Akaiwa, Okayama, 709-0825, Japan
| | - Naohiko Ohkouchi
- Japan Agency for Marine-Earth Science and Technology, Biogeochemistry Research Center, Research Institute for Marine Resources Utilization, Natsushima 2-15, Yokosuka, Kanagawa, 237-0061, Japan
| | - Noko Kuze
- Department of Anthropology, National Museum of Nature and Science, Amakubo 4-1-1, Tsukuba, Ibaraki, 305-0005, Japan
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