Article
Multidisciplinary Sciences
Claudia Wilke, Nicole J. Lahiff, Kris H. Sabbi, David P. Watts, Simon W. Townsend, Katie E. Slocombe
Summary: This article examines the differences between humans and great apes in their ability to share attention with others about external entities. By observing a wild chimpanzee showing an item of interest to a conspecific, the researchers suggest that in specific social conditions, wild chimpanzees may use referential showing gestures like humans, indicating a quantitative rather than qualitative difference between humans and our closest living relatives.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Behavioral Sciences
Jaya K. Matthews, Amanda Ridley, Beth A. Kaplin, Cyril C. Grueter
Summary: In the montane forest of Nyungwe National Park, Rwanda, we investigated the factors influencing chimpanzee party size, finding that the presence of estrous females had the strongest impact. Interestingly, the availability and distribution of important fruits did not directly affect party size, but influenced the presence of estrous females. This suggests that fruit distribution could be the ecological precondition attracting estrous females, the main driver behind larger party sizes.
BEHAVIORAL ECOLOGY AND SOCIOBIOLOGY
(2021)
Article
Multidisciplinary Sciences
Colin M. Brand, Frances J. White, Alan R. Rogers, Timothy H. Webster
Summary: Researchers have analyzed the whole-genome sequences of bonobos and chimpanzees to study their evolutionary history. The results reveal that there was gene flow between eastern and western chimpanzees, with 21% of autosomal DNA in eastern chimpanzees deriving from western chimpanzee introgression. Additionally, all four chimpanzee lineages share a common ancestor about 987,000 years ago, which is earlier than previous estimates. The study also suggests a male reproductive skew throughout chimpanzee evolutionary history and evidence of male-biased dispersal from western to eastern chimpanzees.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Multidisciplinary Sciences
Matthias Allritz, Josep Call, Ken Schweller, Emma S. McEwen, Miguel de Guinea, Karline R. L. Janmaat, Charles R. Menzel, Francine L. Dolins
Summary: This study presented a seminaturalistic virtual environment to six chimpanzees, showing their spatial cognition abilities and the potential of virtual environments for primate research. The chimpanzees exhibited behaviors similar to real-life navigation, indicating the high ecological validity of virtual environments for testing. Virtual environments can provide standardized testing with higher ecological validity than traditional tests in captivity.
Review
Humanities, Multidisciplinary
Lucy Baehren
Summary: Leave-taking behaviors are common in human societies, but have been overlooked from an evolutionary perspective. Studying cross-species data can provide insights into the evolutionary history and social role of leave-taking. This article emphasizes the need for more research on leave-taking and proposes methods for studying it.
HUMANITIES & SOCIAL SCIENCES COMMUNICATIONS
(2022)
Article
Behavioral Sciences
Petar Gabric
Summary: Recent discoveries suggest that semantic compositionality and phenomena resembling paratactic combinations of two clauses may have been present in the communication of the last common ancestor of chimpanzees and humans. A reanalysis of data on drumming sequences by an alpha male chimpanzee in Cote d'Ivoire revealed semantically compositional combined messages, showing relative resemblance to blending and fusion in human languages. Unlike Japanese tits, the elements of the compositional expression in chimpanzees did not have a fixed order, indicating a potential evolution of communication strategies between apes and humans.
Article
Physics, Multidisciplinary
T. Tanaka, D. J. Hinde, M. Dasgupta, E. Williams, K. Vo-Phuoc, C. Simenel, E. C. Simpson, D. Y. Jeung, I. P. Carter, K. J. Cook, N. R. Lobanov, D. H. Luong, C. Palshetkar, D. C. Rafferty, K. Ramachandran
Summary: The mass and angle distributions for the Cr-52 + Pt-198 and Cr-54 + (19)6Pt reactions forming No-250 were measured and subtracted. The experimental mass distributions unexpectedly extended to symmetric splits, while the peak yield remained close to the initial masses, indicating a strong role of fluctuations in mass division early in the collision. This provides insights into the transition from fast energy dissipative deep-inelastic collisions to quasifission.
PHYSICAL REVIEW LETTERS
(2021)
Article
Multidisciplinary Sciences
Lara M. Southern, Tobias Deschner, Simone Pika
Summary: Intraspecies violence, including lethal interactions, is common in mammals while interspecies violence is mainly studied in the context of predation and competition. The study provides information on two lethal coalitionary attacks of chimpanzees on western lowland gorillas in Gabon, discussing them in relation to theories of predation, competition, and intraspecific interactions. The findings may lead to further research on interspecies interactions and aid in understanding behavioral adaptations and interspecific killing in the hominin lineage.
SCIENTIFIC REPORTS
(2021)
Article
Multidisciplinary Sciences
Will Whitham, Steven J. Schapiro, Jolyon Troscianko, Jessica L. Yorzinski
Summary: The eye color of chimpanzees does not effectively conceal their gaze, which contradicts the cooperative eye hypothesis.
SCIENTIFIC REPORTS
(2022)
Article
Agriculture, Dairy & Animal Science
Amy Fultz, Rebekah Lewis, Liam Kelly, Jordan Garbarino
Summary: Chimp Haven is a sanctuary that provides care for retired chimpanzees from biomedical research, rescued from the pet trade or re-homed by other organizations. They use a system of behavioral metrics to guide decision-making and track outcomes for the chimpanzees' welfare. The data is analyzed using various tools such as Google Forms, ZooMonitor, Microsoft Power Bi, Microsoft Excel, and R. These metrics can be a framework for tracking welfare in other sanctuaries and species.
Article
Zoology
Michio Nakamura
Summary: Greeting behaviors among female chimpanzees were investigated in this study, revealing that non-audible greetings, such as tactile or gestural greetings, were also common. Younger females tended to initiate pant grunt greetings towards older females, while older females also occasionally initiated pant grunt greetings towards younger females. The frequency of female-female pant grunts was significantly lower compared to male-directed pant grunts, possibly due to differences in female gregariousness across study sites.
AMERICAN JOURNAL OF PRIMATOLOGY
(2022)
Article
Agriculture, Dairy & Animal Science
Sarah Neal Webb, Steven Schapiro
Summary: The relationship between locomotion and welfare in captive chimpanzees is complex, but increased locomotion is generally considered to indicate improved welfare. However, there is a limited number of studies that have used locomotion as a welfare indicator. Four previously published studies showed that increased locomotion in captive chimpanzees is associated with enhanced welfare, suggesting that time spent in locomotion can be used as a sensitive measure of welfare.
Article
Agriculture, Dairy & Animal Science
Edwin J. C. van Leeuwen, Bernadette M. C. Bruinstroop, Daniel B. M. Haun
Summary: Negative early experiences can have long-lasting negative effects on social functioning in adolescence and adulthood, both in humans and other socially living animals. Recent studies indicate that zoo-housed chimpanzees may suffer lifelong social scars after early trauma. This study investigated whether orphaned chimpanzees living in a sanctuary in Africa would show similar effects. The findings suggest that sanctuaries can be valuable rehabilitation centers for orphaned chimpanzees, helping them cope with early life adversities.
Article
Agriculture, Dairy & Animal Science
Elizabeth R. Magden, Sarah Neal Webb, Susan P. Lambeth, Stephanie J. Buchl, Steven J. Schapiro
Summary: This study investigated the use of lavender as a therapeutic treatment for nonhuman primates (NHPs). Lavender capsules were administered to chimpanzees in an attempt to reduce aggressive behaviors and subsequently decrease the occurrence of wounds. However, while overall wound numbers did not decrease, there was a significant decrease in the percentage of wounds requiring medical intervention during lavender therapy.
Article
Zoology
Aaron A. Sandel, David P. Watts
Summary: Many animals engage in aggression, but chimpanzees are notable for their fatal attacks against adults of their own species. Lethal aggression often occurs between groups, with male chimpanzees forming coalitions to kill members of neighboring communities. In some cases, female-female competition may contribute to community fission.
INTERNATIONAL JOURNAL OF PRIMATOLOGY
(2021)
Article
Family Studies
Olivia Ribeiro, Miguel Freitas, Kenneth H. Rubin, Antonio J. Santos
Summary: This study used a multidimensional and person-centered approach to identify four distinct clusters of adolescents with similar patterns of social and emotional loneliness. Two clusters displayed lower risk of maladjustment and were associated with more prosocial behaviors, while the other two clusters displayed higher risk of maladjustment and were associated with social withdrawal, peer exclusion, and victimization. Girls showed higher levels of social and emotional loneliness compared to boys.
JOURNAL OF CHILD AND FAMILY STUDIES
(2023)
Article
Multidisciplinary Sciences
Gal Badihi, Kirsty E. Graham, Brittany Fallon, Alexandra Safryghin, Adrian Soldati, Klaus Zuberbuhler, Catherine Hobaiter
Summary: Research finds that there are differences in the form and use of leaf-modifying gestures among East African chimpanzee communities, suggesting that these differences are socially derived. This study reveals unexplored variation and flexibility in animal communication, paving the way for future research on socially derived dialects in non-vocal communication.
SCIENTIFIC REPORTS
(2023)
Article
Biochemistry & Molecular Biology
Kirsty Graham, Catherine Hobaiter
Summary: In the comparative study of human and nonhuman communication, ape gesturing provided the first demonstrations of flexible, intentional communication outside human language. We tested human recognition and understanding of 10 frequently used ape gestures and found that humans may retain an understanding of ape gestural communication, drawing deep evolutionary continuity between their communication and our own.
Article
Linguistics
Pritty Patel-Grosz, Matthew Henderson, Patrick Georg Grosz, Kirsty Graham, Catherine Hobaiter
Summary: Major advancements in the study of gestures in both humans and non-human primates have been made in recent decades. This paper critically examines the possibility of shared gestural form types across great ape species, including humans, which may contribute to the existence of gestural universals in both form and meaning. The focus of this study is the hand fling gesture, common to chimpanzees and humans, for which a semantic analysis is provided.
LINGUISTICS VANGUARD
(2023)
Article
Behavioral Sciences
Violet Gibson, Sarah T. Boysen, Catherine Hobaiter, Marina Davila-Ross
Summary: This study investigates the use of objects in social interactions among semi-wild chimpanzees. The results show that chimpanzees adjust their use of objects based on the visual attention of the recipient and the colony membership, suggesting that objects are used by chimpanzees for communication with conspecifics and may be influenced by social factors. These findings contribute to our understanding of the evolution of human nonverbal communication, language, and tool use.
Article
Ecology
Charlotte Wiltshire, James Lewis-Cheetham, Viola Komedova, Tetsuro Matsuzawa, Kirsty E. Graham, Catherine Hobaiter
Summary: Studying animal behavior through video coding allows researchers to extract rich behavioral datasets and validate their reliability. However, manually locating relevant footage and coding behavior is time-consuming. Machine learning approaches can automate data extraction, but tracking nuanced behavior in uncontrolled visual environments remains a challenge.
JOURNAL OF ANIMAL ECOLOGY
(2023)
Article
Biology
Kathelijne Koops, Mimi Arandjelovic, Catherine Hobaiter, Ammie Kalan, Lydia Luncz, Stephanie Musgrave, Liran Samuni, Crickette Sanz, Susana Carvalho
PHYSICS OF LIFE REVIEWS
(2023)
Article
Zoology
Elodie Freymann, Michael A. Huffman, Geresomu Muhumuza, Monday Mbotella Gideon, Klaus Zuberbuhler, Catherine Hobaiter
Summary: This article reviews interspecies grooming events among chimpanzees in the Budongo Forest Reserve in Uganda, as well as a case of interspecies play involving chimpanzees and a red-tailed monkey. The study outlines the general function of this behavior, and discusses the costs and benefits for both the chimpanzee groomers and their interspecies counterparts. The findings contribute to our understanding of how chimpanzees distinguish between affiliative and agonistic species and contexts.
Article
Agriculture, Dairy & Animal Science
Akiho Muramatsu, Tetsuro Matsuzawa
Summary: This study aimed to teach the numerical sequence from 1 to 19 in the decimal system to six chimpanzees. Chimpanzees were able to touch adjacent numerals from 1 to 19 and the factors such as range, adjacency, number of stimuli used, and memory load were found to be important for their learning. Comparing with humans, chimpanzees showed relative difficulty in handling two-digit numerals.
Article
Biology
Patrick J. Tkaczynski, Fabrizio Mafessoni, Cedric Girard-Buttoz, Liran Samuni, Corinne Y. Ackermann, Pawel Fedurek, Cristina Gomes, Catherine Hobaiter, Therese Loehrich, Virgile Manin, Anna Preis, Prince D. Vale, Erin G. Wessling, Livia Wittiger, Zinta Zommers, Klaus Zuberbuehler, Linda Vigilant, Tobias Deschner, Roman M. Wittig, Catherine Crockford
Summary: English summary: Using urinary samples from 170 wild chimpanzees, the study found that shared community and non-genetic maternal effects have a greater influence on urinary cortisol levels than genetic inheritance. Consistent individual variation in cortisol levels was observed, but between-group effects were more influential in determining the variation in this trait. Non-genetic maternal effects accounted for a significant proportion of the individual differences in cortisol levels, suggesting a primary role of shared environment in shaping physiology.
COMMUNICATIONS BIOLOGY
(2023)
Article
Zoology
Toni Romani, Roger Mundry, Gerald Mayanja Shaban, Marek Konarzewski, Mary Namaganda, Catherine Hobaiter, Thibaud Gruber, Thurston Cleveland Hicks
Summary: Recent studies have shown that chimpanzees not only sleep in trees but also construct terrestrial night nests. This behavior is important for understanding behavioral diversity and conserving the species. A comparative study between the decay rates of ground and tree nests in Uganda revealed that ground nests last an average of 238 days, while tree nests last 276 days. The results suggest the need to modify the formula used to estimate chimpanzee density based on nest encounters.
AMERICAN JOURNAL OF PRIMATOLOGY
(2023)
Article
Pediatrics
Maryse Guedes, Manuela Verissimo, Antonio J. Santos
Summary: This study aimed to investigate preschoolers' beliefs, emotions, and intended affiliative preferences towards aggressive, shy, and unsociable peers, taking into account children's sex and age group. The findings showed that preschoolers had less negative perspectives towards shy and unsociable peers compared to aggressive peers. However, they were not fully aware of the different intentions and social motivations of shy and unsociable peers.
Article
Psychology, Educational
Elif Dede Yildirim, Cynthia A. Frosch, Antonio J. Santos, Manuela Verissimo, Kristen Bub, Brian E. Vaughn
Summary: Preschool teachers' perceptions about relationships with students predict children's subsequent social competence and academic progress. This study found that TCRs predict subsequent adaptation because they summarize children's behavioral profiles.
Article
Psychology, Mathematical
Charlotte Grund, Gal Badihi, Kirsty E. Graham, Alexandra Safryghin, Catherine Hobaiter
Summary: Current methodologies pose challenges in studying patterns of gestural communication. To address this, GesturalOrigins presents a bottom-up data collection framework that allows flexible definition of concepts after coding is complete. The methodological tool is illustrated with examples of great ape gestural communication, highlighting differences in action phases and species variation in response latency. By making gesture coding methods transparent and open access, the aim is to promote collaboration and advance comparative gesture research.
BEHAVIOR RESEARCH METHODS
(2023)
Article
Zoology
Catherine Hobaiter, Harmonie Klein, Thibaud Gruber
Summary: This study reports the presence of habitual ground nesting in a newly studied East African chimpanzee population. The researchers found no evidence of socio-ecological factors promoting this behavior and highlighted local factors such as forest disturbance due to poaching and logging as possible deterrents. They argue that the use of population and group-specific behavioral repertoires in flagship species like chimpanzees can be a tool to promote urgent conservation action.
AMERICAN JOURNAL OF PRIMATOLOGY
(2023)