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The urban myth: A lack of agreement between definitions of urban environments used in wildlife health research may contribute to inconsistent epidemiological findings


Worldwide, urbanization and associated anthropogenic land use change is increasing. This has implications for the ecology of wildlife diseases including zoonoses, and relevance for wildlife management, urban planning, and public health. Therefore, wildlife health in ‘urban’ environments is an increasing focus within the published literature. However, researchers use a variety of different classification strategies since there is no established definition of an ‘urban’ environment. It is unclear the degree to which different interpretations of the term ‘urban’ impact our understanding of wildlife health in these environments. In order to explore the implications of various definitions of ‘urban’ and ‘non-urban’ used in wildlife health research, we performed a review of the literature. We determined that 73% of manuscripts that used the term ‘urban’ did not describe or validate the classification metrics employed. We selected 12 binary definitions of ‘urban’ and ‘non-urban’, identified in our literature search, that could reasonably be employed in an Ontario, Canada context, and applied these definitions to a historical raccoon dataset. Mixed univariable logistic regression models were fitted to investigate the impact of different ‘urban’ criteria on the interpretation of Baylisascaris procyonis and canine distemper epidemiology. The proportion of raccoon carcass coordinates classified as ‘urban’ ranged from 10.0% to 91.5%. Individual pairwise agreement between ‘urban’/’non-urban’ designations ranged from 18.3% to 97.7%. Measures of inter-definition agreement ranged from 0.27 to 0.37 depending on the statistic (Cohen’s kappa, prevalence-adjusted and bias-adjusted kappa, and Gwet’s AC1) and all indicated a fair level of overall agreement. The results of regression analyses were discordant among the definitions. These findings emphasize shortfalls in the degree to which ‘urban’ classification methodology is currently documented in the literature. There are multiple distinct metrics and thresholds associated with the term ‘urban’ that have varying relevance depending on the species, pathogen, context, and research question. Therefore, we emphasize the importance of carefully considering what criteria are relevant in a particular context and providing transparent documentation of these criteria. Moving towards specificity in language by referring to the metric employed, instead of the blanket term ‘urban’, will help to improve clarity, capacity for cross-study comparison, and allow us to develop a more mechanistic understanding of wildlife health in ‘urban’ spaces.

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We are grateful to the McLaughlin Library staff for research assistance and support with data analysis. We thank D. Campbell and Canadian Wildlife Health Cooperative staff and volunteers who assisted with data collection as well as Nuisance Wildlife Control Inc., other agencies, and private citizens who submitted carcasses to the Canadian Wildlife Health Cooperative. S.K.F., J.A.G. and S.J.R. were supported by the Ontario Veterinary College and the University of Guelph. S.K.F. was also supported by an Ontario Graduate Scholarship. J.A.G. was also supported by the Natural Sciences and Engineering Research Council.


The authors have no relevant financial or non-financial interests to disclose.

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All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Shannon K French, Jolene A Giacinti and Sarah J Robinson. The first draft of the manuscript was written by Shannon K French, Jolene A Giacinti and Sarah J Robinson and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

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Correspondence to Jolene A. Giacinti.

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French, S.K., Giacinti, J.A., Robinson, S.J. et al. The urban myth: A lack of agreement between definitions of urban environments used in wildlife health research may contribute to inconsistent epidemiological findings. Urban Ecosyst 25, 999–1005 (2022).

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  • Agreement
  • Non-urban
  • Urban
  • Wildlife health research
  • Wildlife health surveillance