Rat Distribution and Movement
Byers K, Lee M, Donovan C, Patrick D, Himsworth CG. 2018. Journal of Urban Ecology, 3(1): https://doi.org/10.1093/jue/jux010
Despite the ubiquity of rats, we lack an understanding of how they move within the urban environment. Traditional tools for studying rat movement, such as capture-mark-recapture, are time-intensive and provide coarse movement estimates. Alternative methods, such as continuous tracking by radio-telemetry are difficult to employ in cities where buildings may obstruct radio signals. Global Positioning System (GPS) tags are a promising alternative for resolving fine-scale movement patterns. To test the utility of GPS tracking for urban rats, we affixed tags to 14 sexually mature Norway rats (Rattus norvegicus) in Vancouver, Canada, using veterinary adhesive and absorbable sutures. Six GPS tags had remote-download capabilities and eight stored location data downloadable upon tag recovery. We did not acquire location data from either tag type. While the data receiver successfully recognized five of six remote-download tags, these tags had not stored any locations. Further, of the three recaptured rats (21.4%), all had dislodged tags, although there were no observable adverse health effects from tag attachment. Given low recapture success, our results suggest that remote-download technologies offer greater potential for data recovery. That remote-download tags did not record locations could be due to obstruction of tag line-of-sight with a satellite either through rat ecology (e.g. burrowing), and/or removal in obstructed areas. Future technological advancements, such as surgically implantable tags that hinder removal, may improve the potential use of GPS tags to track urban rat movement. This information is essential to develop effective rat control strategies and mitigate future rat-related public health concerns.
Or read our research summary: How to Track a Rat: A Trial of GPS Tags
Rats About Town: A Systematic Review of Rat Movement in Urban Ecosystems
Byers K, Lee MJ, Patrick DM, Himsworth CG. 2019. Frontiers in Ecology and Evolution 7:13.
Norway and black rats (Rattus norvegicus and Rattus rattus) are ubiquitous urban pests, inhabiting cities worldwide. Despite their close association with people, urban rats remain difficult to control. This can be partly attributed to a general lack of information on basic rat ecology to inform management efforts. In this systematic review and narrative synthesis, we collate the published literature to provide a comprehensive description of what is known about urban rat movement, including information on home range, site fidelity, dispersal, movement patterns, barriers to, and factors impacting, movement. We also discuss the methodologies used to track and infer rat movement, as well as the advantages and limitations of employing these techniques. Our review suggests that the distances traveled by urban rats are location-specific, determined by both local resource availability and barriers to movement such as roadways. Although roads may impede rat movement, genetic techniques suggest that rats traverse roadways more often than revealed by capture-based tools, while long-distance dispersal events by either natural migration or facilitated by humans (i.e., as stowaways in transport vehicles) can maintain connectivity among distant populations. Because rat movement patterns are related to the transmission of rat-associated pathogens and the success of rodent control programs, these results have implications for city planners, pest control efforts, and public health. Therefore, we emphasize the importance of understanding local rat movement patterns in order to devise and deploy efficient and effective rat mitigation initiatives in urban centers.
Or read our research summary: A Review of Global Rat Movement Ecology in Urban Ecosystems Cities Worldwide
