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Pierron M, Sueur C, Shimada M, MacIntosh AJJ, Romano V. Epidemiological Consequences of Individual Centrality on Wild Chimpanzees. Am J Primatol 2024:e23682. [PMID: 39245992 DOI: 10.1002/ajp.23682] [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: 02/12/2024] [Revised: 08/14/2024] [Accepted: 08/20/2024] [Indexed: 09/10/2024]
Abstract
Disease outbreaks are one of the key threats to great apes and other wildlife. Because the spread of some pathogens (e.g., respiratory viruses, sexually transmitted diseases, ectoparasites) are mediated by social interactions, there is a growing interest in understanding how social networks predict the chain of pathogen transmission. In this study, we built a party network from wild chimpanzees (Pan troglodytes), and used agent-based modeling to test: (i) whether individual attributes (sex, age) predict individual centrality (i.e., whether it is more or less socially connected); (ii) whether individual centrality affects an individual's role in the chain of pathogen transmission; and, (iii) whether the basic reproduction number (R0) and infectious period modulate the influence of centrality on pathogen transmission. We show that sex and age predict individual centrality, with older males presenting many (degree centrality) and strong (strength centrality) relationships. As expected, males are more central than females within their network, and their centrality determines their probability of getting infected during simulated outbreaks. We then demonstrate that direct measures of social interaction (strength centrality), as well as eigenvector centrality, strongly predict disease dynamics in the chimpanzee community. Finally, we show that this predictive power depends on the pathogen's R0 and infectious period: individual centrality was most predictive in simulations with the most transmissible pathogens and long-lasting diseases. These findings highlight the importance of considering animal social networks when investigating disease outbreaks.
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Affiliation(s)
- Maxime Pierron
- Département de Biologie, Faculté des Sciences et Technologies, Université de Lille, Lille, France
| | - Cédric Sueur
- IPHC UMR 7178, CNRS, Université de Strasbourg, Strasbourg, France
- Institut Universitaire de France, Paris, France
- Anthropo-Lab, ETHICS EA7446, Lille Catholic University, Lille, France
| | - Masaki Shimada
- Department of Animal Sciences, Teikyo University of Science, Uenohara, Yamanashi, Japan
| | | | - Valéria Romano
- IPHC UMR 7178, CNRS, Université de Strasbourg, Strasbourg, France
- Wildlife Research Center, Kyoto University, Inuyama, Japan
- IMBE, Aix Marseille University, Avignon University, CNRS, IRD, Marseille, France
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2
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Hearst S, Huang M, Johnson B, Rummells E. Identifying Potential Super-Spreaders and Disease Transmission Hotspots Using White-Tailed Deer Scraping Networks. Animals (Basel) 2023; 13:1171. [PMID: 37048427 PMCID: PMC10093032 DOI: 10.3390/ani13071171] [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: 01/07/2023] [Revised: 03/22/2023] [Accepted: 03/22/2023] [Indexed: 03/29/2023] Open
Abstract
White-tailed deer (Odocoileus virginianus, WTD) spread communicable diseases such the zoonotic coronavirus SARS-CoV-2, which is a major public health concern, and chronic wasting disease (CWD), a fatal, highly contagious prion disease occurring in cervids. Currently, it is not well understood how WTD are spreading these diseases. In this paper, we speculate that "super-spreaders" mediate disease transmission via direct social interactions and indirectly via body fluids exchanged at scrape sites. Super-spreaders are infected individuals that infect more contacts than other infectious individuals within a population. In this study, we used network analysis from scrape visitation data to identify potential super-spreaders among multiple communities of a rural WTD herd. We combined local network communities to form a large region-wide social network consisting of 96 male WTD. Analysis of WTD bachelor groups and random network modeling demonstrated that scraping networks depict real social networks, allowing detection of direct and indirect contacts, which could spread diseases. Using this regional network, we model three major types of potential super-spreaders of communicable disease: in-degree, out-degree, and betweenness potential super-spreaders. We found out-degree and betweenness potential super-spreaders to be critical for disease transmission across multiple communities. Analysis of age structure revealed that potential super-spreaders were mostly young males, less than 2.5 years of age. We also used social network analysis to measure the outbreak potential across the landscape using a new technique to locate disease transmission hotspots. To model indirect transmission risk, we developed the first scrape-to-scrape network model demonstrating connectivity of scrape sites. Comparing scrape betweenness scores allowed us to locate high-risk transmission crossroads between communities. We also monitored predator activity, hunting activity, and hunter harvests to better understand how predation influences social networks and potential disease transmission. We found that predator activity significantly influenced the age structure of scraping communities. We assessed disease-management strategies by social-network modeling using hunter harvests or removal of potential super-spreaders, which fragmented WTD social networks reducing the potential spread of disease. Overall, this study demonstrates a model capable of predicting potential super-spreaders of diseases, outlines methods to locate transmission hotspots and community crossroads, and provides new insight for disease management and outbreak prevention strategies.
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Affiliation(s)
- Scoty Hearst
- The Department of Chemistry and Biochemistry, Mississippi College, Clinton, MS 39056, USA
| | - Miranda Huang
- Department of Wildlife, Fisheries, and Aquaculture, Mississippi State University, Starkville, MS 39762, USA
| | - Bryant Johnson
- The Department of Chemistry and Biochemistry, Mississippi College, Clinton, MS 39056, USA
| | - Elijah Rummells
- The Department of Chemistry and Biochemistry, Mississippi College, Clinton, MS 39056, USA
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3
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Del-Águila-Mejía J, García-García D, Rojas-Benedicto A, Rosillo N, Guerrero-Vadillo M, Peñuelas M, Ramis R, Gómez-Barroso D, Donado-Campos JDM. Epidemic Diffusion Network of Spain: A Mobility Model to Characterize the Transmission Routes of Disease. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:4356. [PMID: 36901366 PMCID: PMC10001675 DOI: 10.3390/ijerph20054356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/23/2023] [Accepted: 02/27/2023] [Indexed: 06/18/2023]
Abstract
Human mobility drives the geographical diffusion of infectious diseases at different scales, but few studies focus on mobility itself. Using publicly available data from Spain, we define a Mobility Matrix that captures constant flows between provinces by using a distance-like measure of effective distance to build a network model with the 52 provinces and 135 relevant edges. Madrid, Valladolid and Araba/Álaba are the most relevant nodes in terms of degree and strength. The shortest routes (most likely path between two points) between all provinces are calculated. A total of 7 mobility communities were found with a modularity of 63%, and a relationship was established with a cumulative incidence of COVID-19 in 14 days (CI14) during the study period. In conclusion, mobility patterns in Spain are governed by a small number of high-flow connections that remain constant in time and seem unaffected by seasonality or restrictions. Most of the travels happen within communities that do not completely represent political borders, and a wave-like spreading pattern with occasional long-distance jumps (small-world properties) can be identified. This information can be incorporated into preparedness and response plans targeting locations that are at risk of contagion preventively, underscoring the importance of coordination between administrations when addressing health emergencies.
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Affiliation(s)
- Javier Del-Águila-Mejía
- Departamento de Medicina Preventiva y Salud Pública y Microbiología, Facultad de Medicina, Universidad Autónoma de Madrid. C. Arzobispo Morcillo 4, 28029 Madrid, Spain
- Centro Nacional de Epidemiología, Instituto de Salud Carlos IIII, Calle de Melchor Fernández Almagro 5, 28029 Madrid, Spain
- Servicio de Medicina Preventiva, Hospital Universitario de Móstoles, Calle Río Júcar s/n, 28935 Móstoles, Spain
| | - David García-García
- Centro Nacional de Epidemiología, Instituto de Salud Carlos IIII, Calle de Melchor Fernández Almagro 5, 28029 Madrid, Spain
- Consorcio de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Calle Monforte de Lemos 3-5, 28029 Madrid, Spain
| | - Ayelén Rojas-Benedicto
- Centro Nacional de Epidemiología, Instituto de Salud Carlos IIII, Calle de Melchor Fernández Almagro 5, 28029 Madrid, Spain
- Consorcio de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Calle Monforte de Lemos 3-5, 28029 Madrid, Spain
- Universidad Nacional de Educación a Distancia (UNED), Calle de Bravo Murillo 38, 28015 Madrid, Spain
| | - Nicolás Rosillo
- Servicio de Medicina Preventiva, Hospital Universitario 12 de Octubre, Avenida de Córdoba s/n, 28041 Madrid, Spain
| | - María Guerrero-Vadillo
- Centro Nacional de Epidemiología, Instituto de Salud Carlos IIII, Calle de Melchor Fernández Almagro 5, 28029 Madrid, Spain
- Consorcio de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Calle Monforte de Lemos 3-5, 28029 Madrid, Spain
| | - Marina Peñuelas
- Centro Nacional de Epidemiología, Instituto de Salud Carlos IIII, Calle de Melchor Fernández Almagro 5, 28029 Madrid, Spain
- Consorcio de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Calle Monforte de Lemos 3-5, 28029 Madrid, Spain
| | - Rebeca Ramis
- Centro Nacional de Epidemiología, Instituto de Salud Carlos IIII, Calle de Melchor Fernández Almagro 5, 28029 Madrid, Spain
- Consorcio de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Calle Monforte de Lemos 3-5, 28029 Madrid, Spain
| | - Diana Gómez-Barroso
- Centro Nacional de Epidemiología, Instituto de Salud Carlos IIII, Calle de Melchor Fernández Almagro 5, 28029 Madrid, Spain
- Consorcio de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Calle Monforte de Lemos 3-5, 28029 Madrid, Spain
| | - Juan de Mata Donado-Campos
- Departamento de Medicina Preventiva y Salud Pública y Microbiología, Facultad de Medicina, Universidad Autónoma de Madrid. C. Arzobispo Morcillo 4, 28029 Madrid, Spain
- Consorcio de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Calle Monforte de Lemos 3-5, 28029 Madrid, Spain
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4
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Greenfield MR, Durden WN, Jablonski TA, Moreland LD, Fabry AC, Gemma LY, Clifford HH. Associates from infancy influence postweaning juvenile associations for common bottlenose dolphins ( Tursiops truncatus) in Florida. J Mammal 2022. [DOI: 10.1093/jmammal/gyac063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
In many long-lived mammalian species, association patterns between individuals have been found to influence sociality, behavioral traits, survival, and longevity. In common bottlenose dolphins (Tursiops truncatus), the early stages of development are of particular importance as associations experienced as dependent calves may influence future association patterns. While behavioral characteristics associated with the transition from a dependent calf state to an independent juvenile state have been documented, there are limited studies that examine associations between these time periods. This study aims to document association longevity for bottlenose dolphins as they transition from calves to juveniles and determine the extent to which kinship plays a role in the development of these associations. Using social network analysis, a generalized linear mixed model (GLMM), and a tiered association scale, we found 53.7% of associations were retained from the calf to the juvenile phase. GLMM results indicated that preferred associates (half-weight index [HWI] > 0.178) from the calf state were 3.6 times more likely to associate in the juvenile state (0.178 > HWI > 0) and 5.67 times more likely to be preferred associates in the juvenile state compared to nonpreferred calf associates. The majority of juveniles, 76.92%, maintained a low–moderate to moderate level association (0.089–0.54) with their mother, and a few retained their mother as their top associate. Kin were preferred associates in 46.15% of cases and found to be the top juvenile associate in 26.92% of cases. Identifying continuity in associations, particularly from the calving state to the juvenile state, is imperative as mammalian association patterns may influence community structure, disease transmission, reproductive success, and predict survival.
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Affiliation(s)
- Michelle R Greenfield
- College of Veterinary Medicine, Cornell University , Ithaca, New York , USA
- Hubbs-SeaWorld Research Institute , Melbourne Beach, Florida , USA
| | - Wendy N Durden
- Hubbs-SeaWorld Research Institute , Melbourne Beach, Florida , USA
| | | | - Lydia D Moreland
- Hubbs-SeaWorld Research Institute , Melbourne Beach, Florida , USA
- Harbor Branch Oceanographic Institute , Fort Pierce, Florida , USA
| | - Agatha C Fabry
- Hubbs-SeaWorld Research Institute , Melbourne Beach, Florida , USA
| | - Lisa Y Gemma
- Hubbs-SeaWorld Research Institute , Melbourne Beach, Florida , USA
| | - Heidy H Clifford
- Hubbs-SeaWorld Research Institute , Melbourne Beach, Florida , USA
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5
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Balasubramaniam KN, Aiempichitkijkarn N, Kaburu SSK, Marty PR, Beisner BA, Bliss-Moreau E, Arlet ME, Atwill E, McCowan B. Impact of joint interactions with humans and social interactions with conspecifics on the risk of zooanthroponotic outbreaks among wildlife populations. Sci Rep 2022; 12:11600. [PMID: 35804182 PMCID: PMC9263808 DOI: 10.1038/s41598-022-15713-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 06/28/2022] [Indexed: 12/21/2022] Open
Abstract
Pandemics caused by pathogens that originate in wildlife highlight the importance of understanding the behavioral ecology of disease outbreaks at human–wildlife interfaces. Specifically, the relative effects of human–wildlife and wildlife-wildlife interactions on disease outbreaks among wildlife populations in urban and peri-urban environments remain unclear. We used social network analysis and epidemiological Susceptible-Infected-Recovered models to simulate zooanthroponotic outbreaks, through wild animals’ joint propensities to co-interact with humans, and their social grooming of conspecifics. On 10 groups of macaques (Macaca spp.) in peri-urban environments in Asia, we collected behavioral data using event sampling of human–macaque interactions within the same time and space, and focal sampling of macaques’ social interactions with conspecifics and overall anthropogenic exposure. Model-predicted outbreak sizes were related to structural features of macaques’ networks. For all three species, and for both anthropogenic (co-interactions) and social (grooming) contexts, outbreak sizes were positively correlated to the network centrality of first-infected macaques. Across host species and contexts, the above effects were stronger through macaques’ human co-interaction networks than through their grooming networks, particularly for rhesus and bonnet macaques. Long-tailed macaques appeared to show intraspecific variation in these effects. Our findings suggest that among wildlife in anthropogenically-impacted environments, the structure of their aggregations around anthropogenic factors makes them more vulnerable to zooanthroponotic outbreaks than their social structure. The global features of these networks that influence disease outbreaks, and their underlying socio-ecological covariates, need further investigation. Animals that consistently interact with both humans and their conspecifics are important targets for disease control.
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Affiliation(s)
- Krishna N Balasubramaniam
- School of Life Sciences, Faculty of Science and Engineering, Anglia Ruskin University, Cambridge, CB1 1PT, UK. .,Department of Population Health and Reproduction, School of Veterinary Medicine (SVM), University of California at Davis, Davis, CA, 95616, USA.
| | | | - Stefano S K Kaburu
- Department of Biomedical Science and Physiology, Faculty of Science and Engineering, University of Wolverhampton, Wolverhampton, WV1 1LY, UK
| | - Pascal R Marty
- Department of Population Health and Reproduction, School of Veterinary Medicine (SVM), University of California at Davis, Davis, CA, 95616, USA.,Zoo Zürich, Zürichbergstrasse 221, 8044, Zurich, Switzerland
| | - Brianne A Beisner
- Animal Resources Division, Yerkes National Primate Research Center, Emory University, Atlanta, GA, 30329, USA
| | - Eliza Bliss-Moreau
- Department of Psychology, University of California, Davis, CA, 95616, USA.,California National Primate Research Center, University of California, Davis, CA, 95616, USA
| | - Malgorzata E Arlet
- Institute of Human Biology and Evolution, Faculty of Biology, Adam Mickiewicz University, 61614, Poznan, Poland
| | - Edward Atwill
- Department of Population Health and Reproduction, School of Veterinary Medicine (SVM), University of California at Davis, Davis, CA, 95616, USA
| | - Brenda McCowan
- Department of Population Health and Reproduction, School of Veterinary Medicine (SVM), University of California at Davis, Davis, CA, 95616, USA.,California National Primate Research Center, University of California, Davis, CA, 95616, USA
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6
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Su M, Jiang Z, Hui C. How Multiple Interaction Types Affect Disease Spread and Dilution in Ecological Networks. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.862986] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Ecological communities are composed of different functional guilds that are engaging in multiple types of biotic interactions. We explore how ecological networks fare when confronting infectious diseases according to density-dependent (DD) and frequency-dependent (FD) transmission modes. Our model shows that network compositions can dictate both disease spreading and the relationship between disease and community diversity (including species richness and Shannon’s diversity) as depicted in the dilution effect. The disease becomes more prevalent within communities harboring more mutualistic interactions, generating a positive relationship between disease prevalence and community diversity (i.e., an amplification effect). By contrast, in communities with a fixed proportion of mutualistic interactions, higher diversity from the balance of competition and predation can impede disease prevalence (i.e., the dilution effect). Within-species disease prevalence increases linearly with a species’ degree centrality. These patterns of disease transmission and the diversity-disease relationship hold for both transmission modes. Our analyses highlight the complex effects of interaction compositions in ecological networks on infectious disease dynamics and further advance the debate on the dilution effect of host diversity on disease prevalence.
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7
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Lemanski N, Silk M, Fefferman N, Udiani O. How territoriality reduces disease transmission among social insect colonies. Behav Ecol Sociobiol 2021; 75:164. [PMID: 34866761 PMCID: PMC8630993 DOI: 10.1007/s00265-021-03095-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 10/03/2021] [Accepted: 10/11/2021] [Indexed: 12/22/2022]
Abstract
Abstract
Social behavior can have a major impact on the dynamics of infectious disease outbreaks. For animals that live in dense social groups, such as the eusocial insects, pathogens pose an especially large risk because frequent contacts among individuals can allow rapid spread within colonies. While there has been a large body of work examining adaptations to mitigate the spread of infectious disease within social insect colonies, there has been less work on strategies to prevent the introduction of pathogens into colonies in the first place. We develop an agent-based model to examine the effect of territorial behavior on the transmission of infectious diseases between social insect colonies. We find that by preventing the introduction of infected foreign workers into a colony, territoriality can flatten the curve of an epidemic, delaying the introduction of an infectious disease and reducing its maximum prevalence, but only for diseases with moderate to low transmissibility. Our results have implications for understanding how pathogen risk influences the evolution of territorial behavior in social insects and other highly social animals. Significance statement Infectious disease outbreaks can impose a large fitness cost to animals that live in social groups. The frequency and pattern of contacts both within and among groups can have a large impact on the speed and extent of an epidemic. Using an individual-based model, we examined how the exclusion of foreign workers from a territory around the nest influences disease transmission between social insect colonies. We find that territoriality can protect colonies from outbreaks of low to moderately contagious pathogens by delaying the spillover from other colonies and reducing the maximum number of workers who are infected. These results suggest that the relative threat posed by infectious diseases may have played an important role in shaping the diversity of territorial behaviors seen in different social insect species. Supplementary Information The online version contains supplementary material available at 10.1007/s00265-021-03095-0.
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Affiliation(s)
- Natalie Lemanski
- Department of Ecology, Evolution, & Natural Resources, Rutgers University, New Brunswick, NJ USA
| | - Matthew Silk
- Department of Ecology & Evolutionary Biology, University of Tennessee, Knoxville, TN USA
| | - Nina Fefferman
- Department of Ecology & Evolutionary Biology, University of Tennessee, Knoxville, TN USA
| | - Oyita Udiani
- Department of Mathematics and Applied Mathematics, Virginia Commonwealth University, Richmond, VA USA
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8
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Evans JC, Hodgson DJ, Boogert NJ, Silk MJ. Group size and modularity interact to shape the spread of infection and information through animal societies. Behav Ecol Sociobiol 2021; 75:163. [PMID: 34866760 PMCID: PMC8626757 DOI: 10.1007/s00265-021-03102-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 11/08/2021] [Accepted: 11/10/2021] [Indexed: 11/23/2022]
Abstract
Social interactions between animals can provide many benefits, including the ability to gain useful environmental information through social learning. However, these social contacts can also facilitate the transmission of infectious diseases through a population. Animals engaging in social interactions therefore face a trade-off between the potential informational benefits and the risk of acquiring disease. Theoretical models have suggested that modular social networks, associated with the formation of groups or sub-groups, can slow spread of infection by trapping it within particular groups. However, these social structures will not necessarily impact the spread of information in the same way if its transmission follows a "complex contagion", e.g. through individuals disproportionally copying the majority (conformist learning). Here we use simulation models to demonstrate that modular networks can promote the spread of information relative to the spread of infection, but only when the network is fragmented and group sizes are small. We show that the difference in transmission between information and disease is maximised for more well-connected social networks when the likelihood of transmission is intermediate. Our results have important implications for understanding the selective pressures operating on the social structure of animal societies, revealing that highly fragmented networks such as those formed in fission-fusion social groups and multilevel societies can be effective in modulating the infection-information trade-off for individuals within them. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s00265-021-03102-4.
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Affiliation(s)
- Julian C. Evans
- Deparment of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - David J. Hodgson
- Centre for Ecology and Conservation, University of Exeter Penryn Campus, Penryn, UK
| | - Neeltje J. Boogert
- Centre for Ecology and Conservation, University of Exeter Penryn Campus, Penryn, UK
| | - Matthew J. Silk
- Centre for Ecology and Conservation, University of Exeter Penryn Campus, Penryn, UK
- National Institute of Mathematical and Biological Synthesis (NIMBioS), University of Tennessee, Knoxville, TN USA
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9
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Fielding HR, Silk MJ, McKinley TJ, Delahay RJ, Wilson-Aggarwal JK, Gauvin L, Ozella L, Cattuto C, McDonald RA. Spatial and temporal variation in proximity networks of commercial dairy cattle in Great Britain. Prev Vet Med 2021; 194:105443. [PMID: 34352518 PMCID: PMC8385416 DOI: 10.1016/j.prevetmed.2021.105443] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 07/15/2021] [Accepted: 07/18/2021] [Indexed: 10/28/2022]
Abstract
The nature of contacts between hosts can be important in facilitating or impeding the spread of pathogens within a population. Networks constructed from contacts between hosts allow examination of how individual variation might influence the spread of infections. Studying the contact networks of livestock species managed under different conditions can additionally provide insight into their influence on these contact structures. We collected high-resolution proximity and GPS location data from nine groups of domestic cattle (mean group size = 85) in seven dairy herds employing a range of grazing and housing regimes. Networks were constructed from cattle contacts (defined by proximity) aggregated by different temporal windows (2 h, 24 h, and approximately 1 week) and by location within the farm. Networks of contacts aggregated over the whole study were highly saturated but dividing contacts by space and time revealed substantial variation in cattle interactions. Cows showed statistically significant variation in the frequency of their contacts and in the number of cows with which they were in contact. When cows were in buildings, compared to being on pasture, contact durations were longer and cows contacted more other cows. A small number of cows showed evidence of consistent relationships but the majority of cattle did not. In one group where management allowed free access to all farm areas, cows showed asynchronous space use and, while at pasture, contacted fewer other cows and showed substantially greater between-individual variation in contacts than other groups. We highlight the degree to which variations in management (e.g. grazing access, milking routine) substantially alter cattle contact patterns, with potentially major implications for infection transmission and social interactions. In particular, where individual cows have free choice of their environment, the resulting contact networks may have a less-risky structure that could reduce the likelihood of direct transmission of infections.
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Affiliation(s)
- Helen R Fielding
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, TR10 9FE, UK
| | - Matthew J Silk
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, TR10 9FE, UK
| | | | - Richard J Delahay
- National Wildlife Management Centre, Animal and Plant Health Agency, Sand Hutton, York, YO41 1LZ, UK
| | - Jared K Wilson-Aggarwal
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, TR10 9FE, UK
| | | | - Laura Ozella
- ISI Foundation, Via Chisola 5, 10126, Torino, Italy
| | - Ciro Cattuto
- ISI Foundation, Via Chisola 5, 10126, Torino, Italy; Computer Science Department, University of Turin, Corso Svizzera 185, 10149, Torino, Italy
| | - Robbie A McDonald
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, TR10 9FE, UK.
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10
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Hobson EA, Silk MJ, Fefferman NH, Larremore DB, Rombach P, Shai S, Pinter-Wollman N. A guide to choosing and implementing reference models for social network analysis. Biol Rev Camb Philos Soc 2021; 96:2716-2734. [PMID: 34216192 PMCID: PMC9292850 DOI: 10.1111/brv.12775] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 06/23/2021] [Accepted: 06/25/2021] [Indexed: 11/29/2022]
Abstract
Analysing social networks is challenging. Key features of relational data require the use of non-standard statistical methods such as developing system-specific null, or reference, models that randomize one or more components of the observed data. Here we review a variety of randomization procedures that generate reference models for social network analysis. Reference models provide an expectation for hypothesis testing when analysing network data. We outline the key stages in producing an effective reference model and detail four approaches for generating reference distributions: permutation, resampling, sampling from a distribution, and generative models. We highlight when each type of approach would be appropriate and note potential pitfalls for researchers to avoid. Throughout, we illustrate our points with examples from a simulated social system. Our aim is to provide social network researchers with a deeper understanding of analytical approaches to enhance their confidence when tailoring reference models to specific research questions.
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Affiliation(s)
- Elizabeth A Hobson
- Department of Biological Sciences, University of Cincinnati, 318 College Drive, Cincinnati, OH, 45221, U.S.A
| | - Matthew J Silk
- Centre for Ecology and Conservation, University of Exeter Penryn Campus, Treliever Road, Penryn, Cornwall, TR10 9FE, U.K
| | - Nina H Fefferman
- Departments of Ecology and Evolutionary Biology & Mathematics, University of Tennessee, 569 Dabney Hall, Knoxville, TN, 37996, U.S.A
| | - Daniel B Larremore
- Department of Computer Science, University of Colorado Boulder, 1111 Engineering Drive, Boulder, CO, 80309, U.S.A.,BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave,, Boulder, CO, 80303, U.S.A
| | - Puck Rombach
- Department of Mathematics & Statistics, University of Vermont, 82 University Place, Burlington, VT, 05405, U.S.A
| | - Saray Shai
- Department of Mathematics and Computer Science, Wesleyan University, Science Tower 655, 265 Church Street, Middletown, CT, 06459, U.S.A
| | - Noa Pinter-Wollman
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, 612 Charles E. Young Drive South, Los Angeles, CA, 90095, U.S.A
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11
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Delahay RJ, de la Fuente J, Smith GC, Sharun K, Snary EL, Flores Girón L, Nziza J, Fooks AR, Brookes SM, Lean FZX, Breed AC, Gortazar C. Assessing the risks of SARS-CoV-2 in wildlife. ONE HEALTH OUTLOOK 2021; 3:7. [PMID: 33834160 PMCID: PMC8024038 DOI: 10.1186/s42522-021-00039-6] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 03/29/2021] [Indexed: 05/03/2023]
Abstract
The novel coronavirus SARS-CoV-2 likely emerged from a wildlife source with transmission to humans followed by rapid geographic spread throughout the globe and severe impacts on both human health and the global economy. Since the onset of the pandemic, there have been many instances of human-to-animal transmission involving companion, farmed and zoo animals, and limited evidence for spread into free-living wildlife. The establishment of reservoirs of infection in wild animals would create significant challenges to infection control in humans and could pose a threat to the welfare and conservation status of wildlife. We discuss the potential for exposure, onward transmission and persistence of SARS-CoV-2 in an initial selection of wild mammals (bats, canids, felids, mustelids, great apes, rodents and cervids). Dynamic risk assessment and targeted surveillance are important tools for the early detection of infection in wildlife, and here we describe a framework for collating and synthesising emerging information to inform targeted surveillance for SARS-CoV-2 in wildlife. Surveillance efforts should be integrated with information from public and veterinary health initiatives to provide insights into the potential role of wild mammals in the epidemiology of SARS-CoV-2.
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Affiliation(s)
- R. J. Delahay
- National Wildlife Management Centre, Animal and Plant Health Agency, Sand Hutton, York, YO41 1LZ UK
| | - J. de la Fuente
- SaBio, Instituto de Investigación en Recursos Cinegéticos IREC-CSIC-UCLM-JCCM, Ronda de Toledo s/n, 13005 Ciudad Real, Spain
- Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK 74078 USA
| | - G. C. Smith
- National Wildlife Management Centre, Animal and Plant Health Agency, Sand Hutton, York, YO41 1LZ UK
| | - K. Sharun
- ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh India
| | - E. L. Snary
- Department of Epidemiological Sciences, Animal and Plant Health Agency, Weybridge, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB UK
| | - L. Flores Girón
- Centre de Rehabilitation des Primates de Lwiro, Kinshasa, Democratic Republic of Congo
| | - J. Nziza
- Gorilla Doctors Inc., P.O. Box 115, Musanze, Rwanda
| | - A. R. Fooks
- Virology Department, Animal and Plant Health Agency, Weybridge, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB UK
| | - S. M. Brookes
- Virology Department, Animal and Plant Health Agency, Weybridge, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB UK
| | - F. Z. X. Lean
- Pathology Department, Animal and Plant Health Agency, Weybridge, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB UK
| | - A. C. Breed
- School of Veterinary Science, University of Queensland, Brisbane, Queensland Australia
- Epidemiology and One Health Section, Department of Agriculture, Water and the Environment, Canberra, Australia
| | - C. Gortazar
- SaBio, Instituto de Investigación en Recursos Cinegéticos IREC-CSIC-UCLM-JCCM, Ronda de Toledo s/n, 13005 Ciudad Real, Spain
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12
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Preston EFR, Thompson FJ, Ellis S, Kyambulima S, Croft DP, Cant MA. Network-level consequences of outgroup threats in banded mongooses: Grooming and aggression between the sexes. J Anim Ecol 2021; 90:153-167. [PMID: 33428240 DOI: 10.1111/1365-2656.13323] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 06/17/2020] [Indexed: 01/10/2023]
Abstract
Animal groups are heterogeneous assemblages of individuals with differing fitness interests, which may lead to internal conflict over investment in group territorial defence. Differences between individuals may lead to different behavioural responses to intergroup conflict, particularly between the sexes. These potential impacts have been little studied. We used social network analysis to investigate the impact of simulated intergroup conflicts on social relationships in groups of wild banded mongooses Mungos mungo, in which intergroup fights are more costly for males than females. We predicted that social cohesion (specifically male-to-male and female-to-male grooming) would increase after conflict, and aggression would decrease, to minimize conflict between the sexes. Simulated intergroup conflicts were performed by exposing banded mongoose groups to scents, 'war cry' playbacks, and live intruders from a rival group. All grooming and aggression interactions between individuals were recorded, and grooming and aggression social networks were created for the 2 days preceding a simulated intergroup conflict (pre-conflict network) and the 2 days after (post-conflict network). We found no evidence of an increase in social cohesion after simulated conflicts, measured as grooming eigenvector centrality. Male-to-male, male-to-female and female-to-male grooming strength decreased after simulated intrusions compared to female-to-female grooming strength. However, male-female aggression decreased in intrusion trials compared to other interaction types, consistent with the hypothesis that intergroup encounters reduce the level of intragroup conflict between males and females. Males were more affected socially by intergroup encounters than females, which may be because they are investing in defence rather than internal relationships. Focusing on individual relationship changes, using social network analysis, can reveal changes in the directionality of behaviour in response to intergroup encounters, and highlight how individual responses to conflict may scale up to affect social networks and, potentially, group performance. This study highlights the importance of studying both group-level behaviours and individual relationships to more fully understand responses to intergroup encounters.
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Affiliation(s)
- Elizabeth F R Preston
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Cornwall, UK
| | - Faye J Thompson
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Cornwall, UK
| | - Samuel Ellis
- Centre for Research in Animal Behaviour, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | | | - Darren P Croft
- Centre for Research in Animal Behaviour, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Michael A Cant
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Cornwall, UK
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13
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Kaufholz T, Franz M, Hammerstein P, Müller-Graf C, Selhorst T. Community structure of domesticated pigs in livestock facilities. Prev Vet Med 2021; 188:105260. [PMID: 33465640 DOI: 10.1016/j.prevetmed.2021.105260] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 12/09/2020] [Accepted: 12/30/2020] [Indexed: 10/22/2022]
Abstract
The social structure of animal groups is considered to have an impact on their health and welfare. This could also be true for animals under commercial conditions, but research in this area has been limited. Pigs for example are known to be very social animals, but information about their grouping behavior is mostly derived from wild boars and a limited number of studies in seminatural and commercial conditions. Specifically under commercial conditions it is still unclear to what extent pig herds organize themselves in subgroups and how such group patterns emerge. To answer these questions, we tracked the positions of about 200 sows inside a barn during ongoing production over a period of five weeks and used these data to construct and analyze the animal contact networks. Our analysis showed a very high contact density and only little variation in the number of other animals that a specific animal is in contact with. Nevertheless, in each week we consistently detected three subgroups inside the barn, which also showed a clear spatial separation. Our results show that even in the high density environment of a commercial pig farm, the behavior of pigs to form differentiated groups is consistent with their behavior under seminatural conditions. Furthermore, our findings also imply that the barn layout could play an important role in the formation of the grouping pattern. These insights could be used to monitor and understand the spread of infectious diseases inside the barn better. In addition, our insights could potentially be used to improve the welfare of pigs.
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Affiliation(s)
- Tobias Kaufholz
- Federal Institute for Risk Assessment (BfR), Max-Dohrn-Str. 8-10, D-10589 Berlin, Germany; Institute for Theoretical Biology, Humboldt-University of Berlin, Philippstr. 13, D-10115 Berlin, Germany.
| | - Mathias Franz
- Federal Institute for Risk Assessment (BfR), Max-Dohrn-Str. 8-10, D-10589 Berlin, Germany
| | - Peter Hammerstein
- Institute for Theoretical Biology, Humboldt-University of Berlin, Philippstr. 13, D-10115 Berlin, Germany
| | - Christine Müller-Graf
- Federal Institute for Risk Assessment (BfR), Max-Dohrn-Str. 8-10, D-10589 Berlin, Germany
| | - Thomas Selhorst
- Federal Institute for Risk Assessment (BfR), Max-Dohrn-Str. 8-10, D-10589 Berlin, Germany
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14
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The role of social structure and dynamics in the maintenance of endemic disease. Behav Ecol Sociobiol 2021; 75:122. [PMID: 34421183 PMCID: PMC8370858 DOI: 10.1007/s00265-021-03055-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 07/09/2021] [Accepted: 07/13/2021] [Indexed: 02/07/2023]
Abstract
Social interactions are required for the direct transmission of infectious diseases. Consequently, the social network structure of populations plays a key role in shaping infectious disease dynamics. A huge research effort has examined how specific social network structures make populations more (or less) vulnerable to damaging epidemics. However, it can be just as important to understand how social networks can contribute to endemic disease dynamics, in which pathogens are maintained at stable levels for prolonged periods of time. Hosts that can maintain endemic disease may serve as keystone hosts for multi-host pathogens within an ecological community, and also have greater potential to act as key wildlife reservoirs of agricultural and zoonotic diseases. Here, we examine combinations of social and demographic processes that can foster endemic disease in hosts. We synthesise theoretical and empirical work to demonstrate the importance of both social structure and social dynamics in maintaining endemic disease. We also highlight the importance of distinguishing between the local and global persistence of infection and reveal how different social processes drive variation in the scale at which infectious diseases appear endemic. Our synthesis provides a framework by which to understand how sociality contributes to the long-term maintenance of infectious disease in wildlife hosts and provides a set of tools to unpick the social and demographic mechanisms involved in any given host-pathogen system. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s00265-021-03055-8.
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15
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Albery GF, Newman C, Ross JB, MacDonald DW, Bansal S, Buesching C. Negative density-dependent parasitism in a group-living carnivore. Proc Biol Sci 2020; 287:20202655. [PMID: 33323092 PMCID: PMC7779509 DOI: 10.1098/rspb.2020.2655] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 11/23/2020] [Indexed: 12/12/2022] Open
Abstract
Animals living at high population densities commonly experience greater exposure to disease, leading to increased parasite burdens. However, social animals can benefit immunologically and hygienically from cooperation, and individuals may alter their socio-spatial behaviour in response to infection, both of which could counteract density-related increases in exposure. Consequently, the costs and benefits of sociality for disease are often uncertain. Here, we use a long-term study of a wild European badger population (Meles meles) to investigate how within-population variation in host density determines infection with multiple parasites. Four out of five parasite taxa exhibited consistent spatial hotspots of infection, which peaked among badgers living in areas of low local population density. Combined movement, survival, spatial and social network analyses revealed that parasite avoidance was the likely cause of this negative density dependence, with possible roles for localized mortality, encounter-dilution effects, and micronutrient-enhanced immunity. These findings demonstrate that animals can organize their societies in space to minimize parasite infection, with important implications for badger behavioural ecology and for the control of badger-associated diseases.
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Affiliation(s)
| | - Chris Newman
- Wildlife Conservation Research Unit, The Recanati-Kaplan Centre, Department of Zoology, University of Oxford, Oxford, UK
| | - Julius Bright Ross
- Wildlife Conservation Research Unit, The Recanati-Kaplan Centre, Department of Zoology, University of Oxford, Oxford, UK
| | - David W. MacDonald
- Wildlife Conservation Research Unit, The Recanati-Kaplan Centre, Department of Zoology, University of Oxford, Oxford, UK
| | - Shweta Bansal
- Department of Biology, Georgetown University, Washington, DC, USA
| | - Christina Buesching
- Wildlife Conservation Research Unit, The Recanati-Kaplan Centre, Department of Zoology, University of Oxford, Oxford, UK
- Irving K. Barber Faculty of Sciences, Okanagan Department of Biology, The University of British Columbia, Kelowna, British Columbia, Canada
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16
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Abstract
Animal populations are occasionally shocked by epidemics of contagious diseases. The ability of social systems to withstand epidemic shocks and mitigate disruptions could shape the evolution of complex animal societies. We present a mathematical model to explore the potential impact of disease on the evolutionary fitness of different organizational strategies for populations of social species whose survival depends on collaborative efficiency. We show that infectious diseases select for a specific feature in the organization of collaborative roles-cohort stability-and that this feature is costly, and therefore unlikely to be maintained in environments where infection risks are absent. Our study provides evidence for an often-stated (but rarely supported) claim that pathogens have been the dominant force shaping the complexity of division of labour in eusocial societies of honeybees and termites and establishes a general theoretical approach for assessing evolutionary constraints on social organization from disease risk in other collaborative taxa.
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Affiliation(s)
- Oyita Udiani
- National Institute for Mathematical & Biological Synthesis, Knoxville, TN, USA.,Department of Mathematics and Applied Mathematics, Virginia Commonwealth University, Richmond, VA, USA
| | - Nina H Fefferman
- National Institute for Mathematical & Biological Synthesis, Knoxville, TN, USA.,Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, USA.,Department of Mathematics, University of Tennessee, Knoxville, TN, USA
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17
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Evans JC, Silk MJ, Boogert NJ, Hodgson DJ. Infected or informed? Social structure and the simultaneous transmission of information and infectious disease. OIKOS 2020. [DOI: 10.1111/oik.07148] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Julian C. Evans
- Dept of Evolutionary Biology and Environmental Studies, Univ. of Zurich Switzerland
| | - Matthew J. Silk
- Centre for Ecology and Conservation, Univ. of Exeter Penryn Campus UK
- Environment and Sustainability Inst., Univ. of Exeter Penryn Campus UK
| | | | - David J. Hodgson
- Centre for Ecology and Conservation, Univ. of Exeter Penryn Campus UK
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18
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Gaughran A, MacWhite T, Mullen E, Maher P, Kelly DJ, Good M, Marples NM. Dispersal patterns in a medium-density Irish badger population: Implications for understanding the dynamics of tuberculosis transmission. Ecol Evol 2019; 9:13142-13152. [PMID: 31871635 PMCID: PMC6912907 DOI: 10.1002/ece3.5753] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 07/26/2019] [Accepted: 09/15/2019] [Indexed: 11/12/2022] Open
Abstract
European badgers (Meles meles) are group-living mustelids implicated in the spread of bovine tuberculosis (TB) to cattle and act as a wildlife reservoir for the disease. In badgers, only a minority of individuals disperse from their natal social group. However, dispersal may be extremely important for the spread of TB, as dispersers could act as hubs for disease transmission. We monitored a population of 139 wild badgers over 7 years in a medium-density population (1.8 individuals/km2). GPS tracking collars were applied to 80 different individuals. Of these, we identified 25 dispersers, 14 of which were wearing collars as they dispersed. This allowed us to record the process of dispersal in much greater detail than ever before. We show that dispersal is an extremely complex process, and measurements of straight-line distance between old and new social groups can severely underestimate how far dispersers travel. Assumptions of straight-line travel can also underestimate direct and indirect interactions and the potential for disease transmission. For example, one female disperser which eventually settled 1.5 km from her natal territory traveled 308 km and passed through 22 different territories during dispersal. Knowledge of badgers' ranging behavior during dispersal is crucial to understanding the dynamics of TB transmission, and for designing appropriate interventions, such as vaccination.
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Affiliation(s)
- Aoibheann Gaughran
- Department of ZoologySchool of Natural SciencesTrinity College DublinDublinIreland
- Trinity Centre for Biodiversity ResearchTrinity College DublinDublinIreland
| | | | - Enda Mullen
- Department of Culture, Heritage and the GaeltachtNational Parks and Wildlife ServiceDublinIreland
| | - Peter Maher
- Department of Agriculture, Food and the MarineDublinIreland
| | - David J. Kelly
- Department of ZoologySchool of Natural SciencesTrinity College DublinDublinIreland
- Trinity Centre for Biodiversity ResearchTrinity College DublinDublinIreland
| | - Margaret Good
- Department of ZoologySchool of Natural SciencesTrinity College DublinDublinIreland
- Trinity Centre for Biodiversity ResearchTrinity College DublinDublinIreland
| | - Nicola M. Marples
- Department of ZoologySchool of Natural SciencesTrinity College DublinDublinIreland
- Trinity Centre for Biodiversity ResearchTrinity College DublinDublinIreland
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19
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Ham C, Donnelly CA, Astley KL, Jackson SYB, Woodroffe R. Effect of culling on individual badger Meles meles behaviour: Potential implications for bovine tuberculosis transmission. J Appl Ecol 2019; 56:2390-2399. [PMID: 34565831 PMCID: PMC8447922 DOI: 10.1111/1365-2664.13512] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 07/30/2019] [Indexed: 11/27/2022]
Abstract
Culling wildlife as a form of disease management can have unexpected and sometimes counterproductive outcomes. In the UK, badgers Meles meles are culled in efforts to reduce badger-to-cattle transmission of Mycobacterium bovis, the causative agent of bovine tuberculosis (TB). However, culling has previously been associated with both increased and decreased incidence of M. bovis infection in cattle.The adverse effects of culling have been linked to cull-induced changes in badger ranging, but such changes are not well-documented at the individual level. Using GPS-collars, we characterized individual badger behaviour within an area subjected to widespread industry-led culling, comparing it with the same area before culling and with three unculled areas.Culling was associated with a 61% increase (95% CI 27%-103%) in monthly home range size, a 39% increase (95% CI 28%-51%) in nightly maximum distance from the sett, and a 17% increase (95% CI 11%-24%) in displacement between successive GPS-collar locations recorded at 20-min intervals. Despite travelling further, we found a 91.2 min (95% CI 67.1-115.3 min) reduction in the nightly activity time of individual badgers associated with culling. These changes became apparent while culls were ongoing and persisted after culling ended.Expanded ranging in culled areas was associated with individual badgers visiting 45% (95% CI 15%-80%) more fields each month, suggesting that surviving individuals had the opportunity to contact more cattle. Moreover, surviving badgers showed a 19.9-fold increase (95% CI 10.8-36.4-fold increase) in the odds of trespassing into neighbouring group territories, increasing opportunities for intergroup contact.Synthesis and applications. Badger culling was associated with behavioural changes among surviving badgers which potentially increased opportunities for both badger-to-badger and badger-to-cattle transmission of Mycobacterium bovis. Furthermore, by reducing the time badgers spent active, culling may have reduced badgers' accessibility to shooters, potentially undermining subsequent population control efforts. Our results specifically illustrate the challenges posed by badger behaviour to cull-based TB control strategies and furthermore, they highlight the negative impacts culling can have on integrated disease control strategies.
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Affiliation(s)
- Cally Ham
- Department of Infectious Disease EpidemiologyScience and Solutions for a Changing Planet DTPMRC Centre for Global Infectious Disease AnalysisImperial College LondonLondonUK
- Institute of ZoologyRegent's Park, LondonUK
| | - Christl A. Donnelly
- Department of Infectious Disease EpidemiologyMRC Centre for Global Infectious Disease AnalysisImperial College LondonLondonUK
- Department of StatisticsUniversity of OxfordOxfordUK
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20
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Dobson ADM, de Lange E, Keane A, Ibbett H, Milner-Gulland EJ. Integrating models of human behaviour between the individual and population levels to inform conservation interventions. Philos Trans R Soc Lond B Biol Sci 2019; 374:20180053. [PMID: 31352880 PMCID: PMC6710576 DOI: 10.1098/rstb.2018.0053] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Conservation takes place within social-ecological systems, and many conservation interventions aim to influence human behaviour in order to push these systems towards sustainability. Predictive models of human behaviour are potentially powerful tools to support these interventions. This is particularly true if the models can link the attributes and behaviour of individuals with the dynamics of the social and environmental systems within which they operate. Here we explore this potential by showing how combining two modelling approaches (social network analysis, SNA, and agent-based modelling, ABM) could lead to more robust insights into a particular type of conservation intervention. We use our simple model, which simulates knowledge of ranger patrols through a hunting community and is based on empirical data from a Cambodian protected area, to highlight the complex, context-dependent nature of outcomes of information-sharing interventions, depending both on the configuration of the network and the attributes of the agents. We conclude by reflecting that both SNA and ABM, and many other modelling tools, are still too compartmentalized in application, either in ecology or social science, despite the strong methodological and conceptual parallels between their uses in different disciplines. Even a greater sharing of methods between disciplines is insufficient, however; given the impact of conservation on both the social and ecological aspects of systems (and vice versa), a fully integrated approach is needed, combining both the modelling approaches and the disciplinary insights of ecology and social science. This article is part of the theme issue 'Linking behaviour to dynamics of populations and communities: application of novel approaches in behavioural ecology to conservation'.
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Affiliation(s)
- Andrew D M Dobson
- School of Geosciences, University of Edinburgh, Edinburgh EH8 9XP, UK
| | - Emiel de Lange
- School of Geosciences, University of Edinburgh, Edinburgh EH8 9XP, UK
| | - Aidan Keane
- School of Geosciences, University of Edinburgh, Edinburgh EH8 9XP, UK
| | - Harriet Ibbett
- Department of Zoology, University of Oxford, Oxford OX1 3SZ, UK
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