The role of red foxes in promoting functional connectivity of the Toronto ravine system through the urban matrix.
Ecology and Biodiversity of Plants and Ecosystems
Final Report Abstract
During my DFG research fellowship, I found urban carnivores can and will disperse seeds both endozoochorously (personally observed during scat collections in urban hiking trails) and diploendozoochorously (observed through captured predation events using camera traps) and there is a strong likelihood they are transporting seeds across ravines. Furthermore, through a functional landscape connectivity analysis using tracking data, I also found these animals will travel on a daily basis between urban forests, crossing residential areas, and using railways and linear open green areas as movement corridors. These urban features streamline their movement and extend their seed dispersal range within the city of Toronto. The fact that we found coyotes will cross residential areas at nighttime and use daily managed urban green areas, such as golf courses and cemeteries, suggests that their participation in the spread of invasive species into urban forests is likely, therefore further research on to the identity of the seeds dispersed is required. In terms of how urbanization may alter seed dispersal ranges of plant species, our analysis considering carnivore spatiotemporal movement patterns and gut passage times from different seed dispersal modes, suggests seed retained for longer period of time either on carnivore fur (epizoochory) or in their guts (endozoochory), are more strongly affected by urbanization, as their seed dispersal distance will be shorter than it would be in rural landscapes, where landscape is not as fragmented as in cities. Due to covid, we were not able to get the permits required to capture foxes and collar them. Fortunately, during that time we found the Ontario Ministry of Natural Resources was actively tracking urban carnivores for another project, and we were able to execute the analysis with their data. However, their data was predominantly on coyotes rather than foxes, nonetheless, both are wide ranging carnivore species living within the city, with similar behavior and foraging patterns, and similar human avoidance patterns. Furthermore, coyotes also had published seed dispersal potential, therefore they were also a good species to initiate urban seed dispersal analysis. Given these considerations, and the fact that we did not know when would covid limitations would be lifted, I opted to run our models using coyote data, and understand seed dispersal by urban carnivores with coyotes as an umbrella species for carnivores. Once we were able to do so following covid restrictions, during the second year of this fellowship, we collected scat samples in hiking trails for both coyotes and foxes, and even though time and funding budget constrains did not allow us to look further into those scat samples during the research fellowship, the samples remain available for future analysis. After our publication looking into carnivores and their prey, the media got interested in our findings and our analysis, given that there is a lot of controversy with the presence of carnivores in the city, and I got invited to come talk to them about their presence in the city, the benefits of having a full ecosystem, including predators, within the city, and ways in which we can improve coexistence. The CBC metro news is a main broadcasting media platform in the city, and after the participation in such interview, I noticed a shift in the general narrative by citizens in social media, it was a success to see inhabitants being more open towards having mammals in the city. Especially the narrative towards coyotes and foxes, for which high levels of fear and uncertainty still exist surrounding their presence, and for which their role in natural balance is so important.
Publications
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Building urban predator-prey networks using camera traps. Food Webs, 37, e00305.
Gelmi-Candusso, Tiziana A.; Brimacombe, Chris; Collinge, Ménard Germain & Fortin, Marie-Josée
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The effect of urbanization and behavioral factors on coyote net displacement and its implications for seed dispersal. Urban Ecosystems, 27(2), 387-397.
Gelmi-Candusso, Tiziana A.; Wheeldon, Tyler J.; Patterson, Brent R. & Fortin, Marie-Josée
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Unveiling Urban Complexity: Research note on integrating OpenStreetMap to enhance representation of fine-scale landscape heterogeneity.
Gelmi-Candusso, Tiziana A.; Rodriguez, Peter & Fortin, Marie-Josée
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Dynamic connectivity assessment for a terrestrial predator in a metropolitan region. Frontiers in Ecology and the Environment, 22(4).
Gelmi‐Candusso, Tiziana A.; Chin, Andrew T. M.; Thompson, Connor A.; McLaren, Ashley A. D.; Wheeldon, Tyler J.; Patterson, Brent R. & Fortin, Marie‐Josée
