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Hakataya S, Katsu N, Okanoya K, Toya G. An exploratory study of behavioral traits and the establishment of social relationships in female laboratory rats. PLoS One 2023; 18:e0295280. [PMID: 38048339 PMCID: PMC10695365 DOI: 10.1371/journal.pone.0295280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 11/18/2023] [Indexed: 12/06/2023] Open
Abstract
There is growing evidence that social relationships influence individual fitness through various effects. Clarifying individual differences in social interaction patterns and determinants for such differences will lead to better understanding of sociality and its fitness consequences for animals. Behavioral traits are considered one of the determining factors of social interaction. The purpose of this study was to explore the effects of individual behavioral traits on social relationship building in laboratory rats (Rattus norvegicus), a highly social species. Initially, the following behavioral characteristics were measured in individuals: tameness (glove test), activity (open field test), exploration (novel object test), sociability (three-chamber test), and boldness (elevated plus maze test). We then used DeepLabCut to behaviorally track three groups of four individuals (12 total) and analyze social behaviors such as approach and avoidance behaviors. Principal component analysis based on behavioral test results detected behavioral traits interpreted as related to exploration, boldness, activity, and tameness, but not sociability. In addition, behavioral tracking results showed consistent individual differences in social behavior indices such as isolation time and partner preference. Furthermore, we found that different components were correlated with different phases of social behavior; exploration and boldness were associated with the early stages of group formation, whereas activity was associated with later stages of relationship building. From these results, we derived hypothesize that personality traits related to the physical and social environment have a larger influence in the relationship formation phase, and the behavioral trait of activity becomes important in the maintenance phase of relationships. Future studies should examine this hypothesis by testing larger group sizes and ensuring there is less bias introduced into group composition.
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Affiliation(s)
- Shiomi Hakataya
- Graduate School of Arts and Sciences, The University of Tokyo, Meguro, Tokyo, Japan
- Advanced Comprehensive Research Organization, Teikyo University, Itabashi, Tokyo, Japan
- Japan Society for the Promotion of Science, Chiyoda, Tokyo, Japan
| | - Noriko Katsu
- Graduate School of Arts and Sciences, The University of Tokyo, Meguro, Tokyo, Japan
- Graduate School of Human Sciences, Osaka University, Suita, Osaka, Japan
| | - Kazuo Okanoya
- Graduate School of Arts and Sciences, The University of Tokyo, Meguro, Tokyo, Japan
- Advanced Comprehensive Research Organization, Teikyo University, Itabashi, Tokyo, Japan
| | - Genta Toya
- Graduate School of Arts and Sciences, The University of Tokyo, Meguro, Tokyo, Japan
- Advanced Comprehensive Research Organization, Teikyo University, Itabashi, Tokyo, Japan
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Mauri D, Bonelli S, Ozella L. The "Second Life" of laboratory rats ( Rattus norvegicus): Assessment of social behavior of a colony of rats based on social network analysis. J APPL ANIM WELF SCI 2023; 26:693-707. [PMID: 36217647 DOI: 10.1080/10888705.2022.2132826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Rattus norvegicus is a social animal and holds a significant economic value, considering its use in scientific research. Here, we use the Social Network Analysis (SNA) approach to study the social interactions of a group of rats held in a post-laboratory animal care facility. We collected interaction data during four study periods, for a total of 60 days. At the group level, rats presented two communities for each study period, consisting mainly of littermates. At individual level, we found that the rats preferred to interact with individuals of the same strain and laboratory of origin and with littermates. At temporal level, we studied how stable social interactions were over time. During the first study period, we found high social stability, whereas the introduction of new individuals in the subsequent period caused social rearrangements; however, the initial social stability was restored. Our findings have shown that studying the social behavior of rats using SNA is a valuable tool for advancing our understanding of the social system of this species, which has the potential to enhance management and welfare practices.
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Affiliation(s)
- Diana Mauri
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
- "La Collina dei Conigli" non-profit Organization, Monza, Italy
| | - Simona Bonelli
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Laura Ozella
- Department of Veterinary Sciences, University of Turin, Turin, Italy
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Dunning J, Burke T, Hoi Hang Chan A, Ying Janet Chik H, Evans T, Schroeder J. Opposite-sex associations are linked with annual fitness, but sociality is stable over lifetime. Behav Ecol 2023; 34:315-324. [PMID: 37192923 PMCID: PMC10183206 DOI: 10.1093/beheco/arac124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 11/27/2022] [Accepted: 12/06/2022] [Indexed: 03/11/2023] Open
Abstract
Animal sociality, an individual's propensity to associate with others, has fitness consequences through mate choice, for example, directly, by increasing the pool of prospective partners, and indirectly through increased survival, and individuals benefit from both. Annually, fitness consequences are realized through increased mating success and subsequent fecundity. However, it remains unknown whether these consequences translate to lifetime fitness. Here, we quantified social associations and their link to fitness annually and over lifetime, using a multi-generational, genetic pedigree. We used social network analysis to calculate variables representing different aspects of an individual's sociality. Sociality showed high within-individual repeatability. We found that birds with more opposite-sex associates had higher annual fitness than those with fewer, but this did not translate to lifetime fitness. Instead, for lifetime fitness, we found evidence for stabilizing selection on opposite-sex sociality, and sociality in general, suggesting that reported benefits are only short-lived in a wild population, and that selection favors an average sociality.
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Affiliation(s)
- Jamie Dunning
- Department of Life Sciences, Imperial College London, UK
| | - Terry Burke
- Ecology and Evolutionary Biology, School of Biosciences, The University of Sheffield, UK
| | - Alex Hoi Hang Chan
- Department of Life Sciences, Imperial College London, UK
- Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Germany
- Max Plank Institute of Animal Behaviour, Germany
| | - Heung Ying Janet Chik
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Netherlands
- School of Natural Sciences, Macquarie University, Australia
| | - Tim Evans
- Center for Complexity Science, Imperial College London, UK
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Lee SLT, Ahmed S, Horbal L, Pietruszewski T, Hu Q, Markus EJ. Social factors influence solo and rat dyads exploration of an unfamiliar open field. Anim Cogn 2023; 26:703-708. [PMID: 35931922 DOI: 10.1007/s10071-022-01664-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 07/17/2022] [Accepted: 07/26/2022] [Indexed: 11/28/2022]
Abstract
Exploring new and unfamiliar environments is critical for survival, providing information on food, shelter, mates, and sources of danger. The open field paradigm is commonly used to study exploration and anxiety-like behaviors in the lab. Many social animals, like humans and rats, may explore their environments in social groups; however, relatively few studies have investigated the influence of conspecifics on open field activity. Here, we provide a comparison of individual (solo) or pairs of male rats (dyads) exploring and interacting across repeated exposures to an unfamiliar (Day 1) or more familiar (Day 2) open field. Both solo rats and dyads explored a larger area, traveled further, and spent less time near the maze walls on the second maze exposure. Solo rats explored a larger area and spent less time near the maze walls than dyads on both days because dyads spent more time socializing rather than exploring the environment. Furthermore, we compared familiar dyads that were co-housed for seven days versus stranger dyads that met for the first time in the open field. While familiar and stranger dyads did not differ in maze exploration, strangers spent more time interacting nose to nose than nose to anogenital. These results indicate that the degree of familiarity with the environment does not interact with the tendency of dyads to socialize rather than explore the environment.
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Affiliation(s)
- Shang Lin Tommy Lee
- Division of Behavioral Neuroscience, Department of Psychological Sciences, University of Connecticut, 406 Babbidge Road, Unit 1020, Storrs, CT, 06269, USA
| | - Saheeb Ahmed
- Division of Behavioral Neuroscience, Department of Psychological Sciences, University of Connecticut, 406 Babbidge Road, Unit 1020, Storrs, CT, 06269, USA
| | - Logan Horbal
- Division of Behavioral Neuroscience, Department of Psychological Sciences, University of Connecticut, 406 Babbidge Road, Unit 1020, Storrs, CT, 06269, USA
| | - Thomas Pietruszewski
- Division of Behavioral Neuroscience, Department of Psychological Sciences, University of Connecticut, 406 Babbidge Road, Unit 1020, Storrs, CT, 06269, USA
| | - Qingli Hu
- Division of Behavioral Neuroscience, Department of Psychological Sciences, University of Connecticut, 406 Babbidge Road, Unit 1020, Storrs, CT, 06269, USA
| | - Etan J Markus
- Division of Behavioral Neuroscience, Department of Psychological Sciences, University of Connecticut, 406 Babbidge Road, Unit 1020, Storrs, CT, 06269, USA.
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