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Judson K, Sanz C, Ebombi TF, Massamba JM, Teberd P, Abea G, Mbebouti G, Matoumona JKB, Nkoussou EG, Zambarda A, Brogan S, Stephens C, Morgan D. Socioecological factors influencing intraspecific variation in ranging dynamics of western lowland gorillas (Gorilla gorilla gorilla) in Ndoki Forest. Am J Primatol 2024; 86:e23586. [PMID: 38151775 DOI: 10.1002/ajp.23586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 11/13/2023] [Accepted: 12/10/2023] [Indexed: 12/29/2023]
Abstract
Ranging dynamics are physical and behavioral representations of how different socioecological factors affect an organism's spatial decisions and space use strategies. Western lowland gorillas (Gorilla gorilla gorilla) are a model species to investigate the drivers of spatial dynamics based on both the natural variation in socioecological factors within the species and compared with their mountain gorilla counterparts. In this study, we evaluate the influences of resource seasonality and social dynamics on variation in home range size, utilization, and intergroup overlap among multiple gorilla groups over an 8-year study period in the northern Republic of Congo. This study shows that western lowland gorillas can have small home ranges comparable to mountain gorillas, rather than universally larger home ranges as previously supposed, and that home ranges are stable through time. The largest source of variation in space use was the degree of intergroup home range overlap. The study groups did not demonstrate intraspecific variation in range size nor changes in intergroup overlap with respect to seasonality of fruit resources, but all groups demonstrated expansion of monthly range and core area with group size, matching predictions of intragroup feeding competition. These findings highlight the potential impact of intergroup relationships on space use and prompt further research on the role of social dynamics in ranging strategies. In this study, we reveal a greater degree of variability and flexibility in gorilla ranging behavior than previously realized which is relevant to improving comparative studies and informing conservation strategies on behalf of these endangered primates.
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Affiliation(s)
- Kathryn Judson
- Department of Anthropology, Washington University in Saint Louis, Saint Louis, Missouri, USA
| | - Crickette Sanz
- Department of Anthropology, Washington University in Saint Louis, Saint Louis, Missouri, USA
- Wildlife Conservation Society, Congo Program, Brazzaville, Republic of Congo
| | | | - Jean Marie Massamba
- Wildlife Conservation Society, Congo Program, Brazzaville, Republic of Congo
| | - Prospère Teberd
- Wildlife Conservation Society, Congo Program, Brazzaville, Republic of Congo
| | - Gaston Abea
- Wildlife Conservation Society, Congo Program, Brazzaville, Republic of Congo
| | - Gaeton Mbebouti
- Wildlife Conservation Society, Congo Program, Brazzaville, Republic of Congo
| | | | | | - Alice Zambarda
- Wildlife Conservation Society, Congo Program, Brazzaville, Republic of Congo
| | - Sean Brogan
- Wildlife Conservation Society, Congo Program, Brazzaville, Republic of Congo
| | - Colleen Stephens
- Department of Anthropology, Washington University in Saint Louis, Saint Louis, Missouri, USA
| | - David Morgan
- Fisher Center for the Study and Conservation of Apes, Chicago, Illinois, USA
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Morris-Drake A, Kennedy P, Braga Goncalves I, Radford AN. Variation between species, populations, groups and individuals in the fitness consequences of out-group conflict. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210148. [PMID: 35369741 PMCID: PMC8977661 DOI: 10.1098/rstb.2021.0148] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Out-group conflict is rife in the natural world, occurring from primates to ants. Traditionally, research on this aspect of sociality has focused on the interactions between groups and their conspecific rivals, investigating contest function and characteristics, which group members participate and what determines who wins. In recent years, however, there has been increasing interest in the consequences of out-group conflict. In this review, we first set the scene by outlining the fitness consequences that can arise immediately to contest participants, as well as a broader range of delayed, cumulative and third-party effects of out-group conflict on survival and reproductive success. For the majority of the review, we then focus on variation in these fitness consequences of out-group conflict, describing known examples both between species and between populations, groups and individuals of the same species. Throughout, we suggest possible reasons for the variation, provide examples from a diverse array of taxa, and suggest what is needed to advance this burgeoning area of social evolution. This article is part of the theme issue 'Intergroup conflict across taxa'.
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Affiliation(s)
- Amy Morris-Drake
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Patrick Kennedy
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Ines Braga Goncalves
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Andrew N Radford
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
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García MG, de Guinea M, Bshary R, van de Waal E. Drivers and outcomes of between-group conflict in vervet monkeys. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210145. [PMID: 35369750 PMCID: PMC8977665 DOI: 10.1098/rstb.2021.0145] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Neighbouring groups compete over access to resources and territories in between-group encounters, which can escalate into between-group conflicts (BGCs). Both the ecological characteristics of a territory and the rival's fighting ability shape the occurrence and outcome of such contests. What remains poorly understood, however, is how seasonal variability in the ecological value of a territory together with fighting ability related to the likelihood of between-group encounters and the extent to which these escalate into conflicts. To test this, we observed and followed four vervet monkey groups in the wild, and recorded the group structure (i.e. size, composition), the locations and the outcomes of 515 BGCs. We then assessed key ecological measures at these locations, such as vegetation availability (estimated from Copernicus Sentinel 2 satellite images) and the intensity of usage of these locations. We tested to what extent these factors together influenced the occurrence and outcomes of BGCs. We found that the occurrence of BGCs increased at locations with higher vegetation availability relative to the annual vegetation availability within the group's home territory. Also, groups engaging in a BGC at locations far away from their home territory were less likely to win a BGC. Regarding group structure, we found that smaller groups systematically won BGCs against larger groups, which can be explained by potentially higher rates of individual free-riding occurring in larger groups. This study sheds light on how the ecology of encounter locations in combination with a group's social characteristics can critically impact the dynamics of BGCs in a non-human primate species. This article is part of the theme issue ‘Intergroup conflict across taxa’.
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Affiliation(s)
- Miguel Gareta García
- Inkawu Vervet Project, Mawana Game Reserve, KwaZulu Natal 3115, South Africa.,Department of Eco-Ethology, Faculty of Biology, University of Neuchâtel, Rue Emile Argand 11, Neuchâtel 2000, Switzerland
| | - Miguel de Guinea
- Movement Ecology Laboratory, Alexander Silverman Institute of Life Sciences, Department of Ecology, Evolution and Behavior, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Redouan Bshary
- Inkawu Vervet Project, Mawana Game Reserve, KwaZulu Natal 3115, South Africa.,Department of Eco-Ethology, Faculty of Biology, University of Neuchâtel, Rue Emile Argand 11, Neuchâtel 2000, Switzerland
| | - Erica van de Waal
- Inkawu Vervet Project, Mawana Game Reserve, KwaZulu Natal 3115, South Africa.,Department of Ecology and Evolution, Faculty of Biology and Medicine, University of Lausanne, Lausanne 1015, Switzerland
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