FW 403 (001) Fall 2025 Urban Wildlife Management

Urban trophic systems that involve mammals are a largely understudied field. Barriers to this research include the cost of conducting field observations or DNA analyses. Camera traps can be a cost-effective method to opportunistically record predator-prey interactions. Potential prey encounters can also be recorded with camera traps and used to build trophic networks. 

This study was conducted in Toronto, Canada, a highly urbanized area. The focal predator species were red foxes and coyotes because they have opportunistic diets and have adapted to thrive in urban areas. 33 motion-detecting cameras were placed at approximately knee height on trees and lamp posts along previously laid transects throughout the city from October 2020 to September 2021. Any image containing more than two animals was considered a predation event. Potential predation events were recorded as each species was detected on the same camera less than five minutes apart. This data was used to create bipartite networks that demonstrate the urban predator-prey interactions and potential interactions. Their results found a total of 43 combined predation events and 299 combined potential interactions for red foxes and coyotes. 

Images of recorded predation events by coyotes (uppers) and red foxes (lower)

The first thing this paper failed to address was the impact of COVID-19 protocols in urban areas on these predator-prey interactions. I suspect that over the course of the study, restrictions lessened, which would likely be associated with a decline in these interactions in urban areas, as we have discussed in class. Regarding the researchers’ methods, site-specific information should’ve been included in their analysis of interactions to develop a more intricate food web of the whole study area. I also think it would be important to note whether the prey or predator was detected first when documenting potential predator-prey interactions. The difference could be significant enough to remove some of the observations as potential interactions. Also, the researchers of this paper urge future researchers to consider the likelihood of a predation event in their analysis of potential encounter events, which could also result in a more detailed food web. 

Overview:

The title of the article I will be reviewing is “Greater consumption of protein-poor anthropogenic food by urban relative to rural coyotes increases diet breadth and potential for human–wildlife conflict”. This study focuses on the diet of an urban-adapted generalist species called Canis latrans, more commonly known as coyotes. This species has been increasingly present in urban environments, and this has led to dietary changes for urban coyotes. This study examines how these urban coyotes have adapted to consuming more anthropogenic food sources in their diet (bird seed, compost, pet food, trash, etc.). Although having a broad number of dietary sources can benefit coyotes, consuming these anthropogenic sources may lead to increased amounts of human-wildlife conflict in urban areas. Coyotes are very flexible when it comes to their dietary and environmental needs, so this explains why urban coyote populations have been increasing in recent years. In order to better understand the role of anthropogenic food sources in urban coyote diets and how these impact human-wildlife conflicts, this study compared the diets of urban and rural coyotes. It aimed to determine what kinds/amounts of anthropogenic food were part of urban coyote diets and how this impacted the prevalence of conflicts between urban coyotes and humans. 

Methods:

The diets of coyotes from several urban and rural areas of Canada were compared for this study. The researchers collected samples of coyote scat and hair to conduct the necessary analysis for this experiment. The scat samples were collected in a variety of areas that had either received reports of coyote sightings, had coyote tracks, or where radio-collared coyotes had been located. Several characteristics were utilized to distinguish the coyote scat from other similar species such as domestic dogs, wolves, or foxes. The items found in the scat were categorized to separate natural and anthropogenic food sources. The prevalence and relative abundance of each diet component were calculated for both the urban and rural coyotes. These comparisons were able to give an in-depth understanding of the differences between urban and rural coyote diets. 

The hair samples were collected for the purpose of performing stable isotope analysis. These samples were taken from coyotes that had known histories of having conflicts with people. This type of analysis was able to give an accurate and longer-term view of anthropogenic food consumption by the coyotes of interest. The hair samples were taken from coyotes that had been live-trapped as well as ones that had been killed for various reasons. In order for a coyote to be categorized as conflict-prone, it had to have received complaints from the public regarding its behavior. The bodily conditions of each coyote were observed at the time that the hair sample was retrieved, and each coyote was analyzed for disease (sarcoptic mange infestation). Once the hair samples were obtained, they were used to perform the stable isotope analysis. 

Results:

The analysis of scat samples found that urban coyotes had more diverse diets when compared to rural coyotes. This was true at both the population level and the individual level. It also showed that urban coyotes consumed anthropogenic food sources much more often than rural coyotes (26% of all urban coyote scat samples and <1% of all rural coyote scat samples). Additionally, urban coyotes consumed far less animals when compared to rural coyotes. However, urban coyotes did consume small mammals more frequently than rural coyotes. 

Figure 2 Diet diversity of urban coyote scats from two urban (black bars) and two rural sites (white bars). We measured population diet diversity by calculating Shannon’s H′ index from pooled scats (a) and measured individual diet breadth using the number of species per scat (b). Bars show mean values and error bars indicate standard error.

Figure 3 Differences in prey use in urban (black bars) and rural (white bars) coyote scats from two urban and two rural studies in Alberta, Canada. (a) The frequency of occurrence (displayed as proportion of scats that contained item) for the diet items that differed significantly between urban and rural coyotes. (b) The proportion of analyzed scats from urban or rural coyotes that contained prey remains such as hair, bones, or teeth (animals) and all other items including anthropogenic food. Error bars show standard deviation.

The analysis of the hair samples was able to support several conclusions. Urban coyotes were more likely to experience poor bodily conditions and disease presence. This was also true for urban coyotes that had behaved in conflict-prone ways. The coyotes that had not caused human-wildlife conflict were less likely to have poor bodily conditions and disease. The urban coyotes did consume more anthropogenic food, but they did consume similar amounts of protein as rural coyotes. Interestingly, this study found that the conflict-prone urban coyotes did not consume significantly more anthropogenic food sources. However, it did find that the conflict-prone urban coyotes did consume significantly less protein when compared to all other sampled coyotes. 

Reflection/Critiques:

Overall, this study was able to confirm that urban coyotes had more diverse diets when compared to rural coyotes. This is largely due to the consumption of additional anthropogenic food sources by urban coyotes. Additionally, conflict-prone urban coyotes consumed similar amounts of anthropogenic food sources. However, these coyotes consumed less protein when compared to the rest of the samples. 

The use of anthropogenic food sources has likely contributed to the increased prevalence of coyotes in urban areas. These additional food sources allow coyotes to be less reliant on any one particular source of food, which increases their likelihood for survival. Anthropogenic food sources are often consistently available, which may cause coyotes to favor them over natural food sources in some scenarios. 

This study aimed to determine if the use of anthropogenic food sources increased the prevalence of human-coyote conflicts in urban areas. According to its findings, the consumption of anthropogenic food sources does not drive these conflicts. Instead, the amount of protein consumption by coyotes was correlated with the likelihood of them exhibiting conflict-prone behavior. The coyotes that were reported as being conflict-prone had significantly less protein in their diets and were more likely to be in poor health. These coyotes likely exhibited conflict-prone behaviors due to their lack of health and bodily vigor. They would likely be more reliant on anthropogenic food sources since they can be easily obtained and are consistently available. 

One critique for this paper is that the scat samples were collected across multiple different years in each location. This is problematic because many influential variables can change over these long time periods. Things such as weather, prey populations, predator populations, human presence, urbanization, and anthropogenic food sources can change significantly across multiple years. This decreases the reliability of the conclusions that were drawn from the analysis of the scat samples. Although it is not completely clear how much this would impact the findings, it certainly has some meaningful impact and should be acknowledged. 

Another critique is that there was a small and unevenly distributed sample size for the coyote hair analysis. According to the paper, only 72 hair samples were analyzed across urban and rural coyotes. Of these samples, 49 were urban and 23 were rural. This is problematic because the overall sample size is small, which decreases the statistical soundness of any conclusions that were drawn from it. Additionally, far more urban samples were analyzed when compared with rural samples. This increases the likelihood of random variation causing inaccurate results for the rural samples since there were so few. This issue could be fixed by increasing the total number of samples and by ensuring that they were evenly distributed between urban and rural coyotes.  

Reference:

Murray, M., Cembrowski, A., Latham, A.D.M., Lukasik, V.M., Pruss, S. and St Clair, C.C. (2015), Greater consumption of protein-poor anthropogenic food by urban relative to rural coyotes increases diet breadth and potential for human–wildlife conflict. Ecography, 38: 1235-1242. https://doi-org.prox.lib.ncsu.edu/10.1111/ecog.01128

Background/Overview: This study was conducted in Italy and aims to understand ways wildlife adapts to urban environments through camera trapping. Italy, like many parts of the world is experiencing rapid urbanization and there is currently a lack of research on the topic. Camera trapping has been shown to be very effective in analyzing animal behavior but has not been used much due to privacy concerns and conflicts with landowners. The study adresses the spatial and temporal changes in wildlife behavior between rural and urban environments. The researchers hypothesized that species will modify behavior to minimize contact with humans, behaviors will change due to changes in vegetation and light pollution levels, predator-prey relationships will change, and spatiotemporal overlaps between species that are well-adapted to urban areas versus species that occasionally use urban areas.

Methods: The study site was located in Firenze, Italy. It was selected due to the amount of artificial surfaces which were mainly mid-rise and low-rise buildings. The researchers placed a grid of 1kmX1km squares and categorized each square by landcover type. These types included cultivated areas, riparian habitats, urban green space, and human settlements. From these categories, 35 locations were chosen as sites for camera traps. The camera traps were in place from March 2023 to May 2024 and they were set to record for 60 seconds for each event. Videos were discarded when species could not be identified. These species were then identified as either urban dwellers or urban visitors. The vegetation cover for each site was also analyzed. The study mentioned that there was a lack of GIS data for the area and much of the data had to be collected directly from the field. The amount of artificial light in each site was determined through the Bortle Index Scale where 1 is no light and 9 contains extreme light pollution. Human presence for each site was determined through the proportion of humans captured through the camera traps. The study addressed privacy concerns through obtaining permits and permission from landowners. There was also a QR code placed at each site with a request form to remove human subject videos and to report vandalism.

Below is a map of the camera trap sites

Results/Discussion: From the camera trap data, there were 7880 recordings with 72 species identified. The majority of the species were humans. The results demonstrated more temporal overlap between predators and prey in urban settings compared to those that were more rural. Humans were found to spatially overlap 100% with all other species recorded. Urban areas contained fewer predators which allowed species such as hares and deer shift from being nocturnal to diurnal. This behavior change was seen in areas that contained urban green spaces. It was also noted that these species were being fed by humans and consuming waste.

Below is a graph of the proportion of species found in camera trap data.

This graph shows the change in species richness across two different variables.

In the discussion, it was determined that wildlife adjust their behaviors to avoid humans while exploiting their resources. It was also found that the increase in light pollution decreased predators’ ability to hunt, thus reducing species richness in urban areas. Suburuban areas were found to contain the highest species richness because these areas included an overlap of urban dweller and urban visitor species. In urban areas, species richness was higher in areas that contained more vegetation and green space. The study came to the conclusion that managing for green space and limiting artificial light disturbances are key in managing urban wildlife. It was then suggested for more studies like these in other cities for a better understanding of urban wildlife.

Reflection/Critique: Overall, I thought this was a very interesting study. I chose this paper because I haven’t read much literature about camera traps and it was also published less than a month ago. I agree with the paper in that there is a need for more camera trap studies in urban areas as they are effective in monitoring wildlife. It would be interesting to see this done locally. My one critique is about the GIS data. I know they said there was a lack of data for the study area but it may have been beneficial in collecting it as a part of their project so they could have something to look back on and so that the study could be replicated easier. I’m sure collecting this type of data is time consuming and they might not have had time to do it. This could be something that could be done in future studies of the same site.

Reference:

Mori, E., Lazzeri, L., Maggioni, M., Viviano, A., Guerri, G., Morabito, M., Martini, S., Dondina, O., Sogliani, D., Scarfò, M., & Ancillotto, L. (2025). Camera‐traps and the city: Spatiotemporal adaptations of wildlife to Urban Environments. Ecological Solutions and Evidence, 6(3). https://doi.org/10.1002/2688-8319.70115

Overview

The article I reviewed is Enhancing pollination supply in an urban ecosystem through landscape modifications by Davis et al. (2017), published in Landscape and Urban Planning. As urban farming becomes more common, understanding how to support pollinators in cities is increasingly important. This study examines whether converting small portions of turf grass into flowering habitat could increase pollinator supply and benefit urban agriculture. The researchers used Chicago, Illinois, as their study area and focused on modeling how different strategies for increasing floral resources, such as planting flowers in city parks, residential yards, or near community gardens, would impact pollination availability. The goal was to help city planners and residents find the most effective way to support pollinators and improve crop yields in urban gardens.

Methods

The researchers first mapped the locations of urban farms, community gardens, and home food gardens using Google Earth imagery. They then collected pollinator specimens from 15 community gardens across Chicago using colored pan traps filled with a detergent solution. Traps were arranged in a 3 x 3 meter grid, spaced one meter apart, with alternating colors, and left out for one daylight cycle each month during July, August, and September 2009.

Specimens were preserved in ethanol and later identified to genus or species. Using this field data, the team validated the InVEST pollination model, which uses land cover, nesting resources, and floral resources to predict pollinator abundance. They then modeled several scenarios simulating the conversion of one to five percent of Chicago’s turf grass to pollinator-friendly flower gardens in different locations, including city parks, private yards, and areas within varying distances of community gardens, to compare how each strategy affected pollination supply across the city.

Results

The study found that augmenting floral resources can increase pollination supply in Chicago, but the most effective strategy depends on the type of urban agriculture. For home gardens, distributing flowers throughout the city was most beneficial, while concentrating flowers near community gardens and urban farms provided the greatest pollination benefits for those larger sites. The InVEST model predicted 46 percent of the variation in native bee richness, indicating that it can reliably identify areas with high or low pollination potential. The results highlight that city parks, forest preserves, and green spaces act as pollination hotspots, whereas downtown and heavily industrialized areas may have lower pollination supply.

Fig. 1. Study area (Chicago, Illinois)with inset of United States.

Fig. 2. Map of pollination supply score and location of sites used for model validation, i.e. sites where bees were collected.

Fig. 4. Effect of landscape modification scenarios on pollination supply scores.

Critiques and Reflection

While this article provides valuable insight into the role of bees in urban pollination and demonstrates how modifying turf grass can enhance pollinator supply for both residential and commercial agriculture, it has some limitations. One notable omission is the lack of consideration for other important insect orders, such as Diptera (flies) and Lepidoptera (butterflies and moths), which also play critical roles in pollination. Including these groups could provide a more complete understanding of urban pollinator communities.

The study excels in highlighting the underutilized potential of urban green spaces, particularly turf grass and ornamental plantings, and shows how thoughtful landscape modifications can provide both ecological and economic benefits. However, greater attention could be given to the use of native plantings, which not only offer nectar resources but also serve as host plants for pollinators, contributing to the restoration of urban biodiversity and supporting the life cycles of native insects.

Despite these limitations, the article provides strong empirical evidence for the importance of maximizing the ecological value of urban green spaces. It demonstrates that targeted interventions, such as converting portions of turf grass to flower gardens, can meaningfully enhance pollinator populations and improve urban agricultural productivity, making it a valuable resource for both researchers and urban planners.

Reference 

Amélie Y. Davis, Eric V. Lonsdorf, Cliff R. Shierk, Kevin C. Matteson, John R. Taylor, Sarah T. Lovell, Emily S. Minor. (2017). Enhancing pollination supply in an urban ecosystem through landscape modifications, 162, 157-166. https://doi.org/10.1016/j.landurbplan.2017.02.011

This study, “Reconciling cities with nature: Identifying local Blue-Green Infrastructure interventions for regional biodiversity enhancement,” was written by Donati et al. and published on August 15th, 2022. It seeks to answer the question of how we can better support regional biodiversity enhancement in cities through local Blue-Green Infrastructure (BGI) interventions. To address this, the researchers focused on how amphibian species are affected by urbanization, using the Swiss lowlands as a case study. Amphibians were chosen because they are particularly sensitive to environmental conditions compared to most other animal groups and because they depend on both terrestrial and aquatic habitats.

The researchers approached this question using habitat suitability models, high-resolution land cover data, and circuit theory models to assess biodiversity patterns in both urban and non-urban areas. In identifying the key habitat features that best support regional biodiversity enhancement, they found that stepping-stone areas allowing amphibians to move between habitats were the most important. The study highlighted features such as forest edges, wet forests, moist soils, and riparian habitats. From this, the researchers concluded that up to 15% of urban spaces could contribute to regional ecological connectivity if strategically planned and intentionally managed. Overall, the study shows that cities, if designed with biodiversity in mind, have the potential to significantly enhance ecological connectivity and support regional biodiversity.

This study is well-written and highly credible, being peer-reviewed and supported by a substantial amount of evidence. It does an excellent job of presenting its research, providing clear justification for its methodology, reasoning, and results. The focus on amphibians is particularly strong, as the authors clearly explain why this group was chosen and how it effectively demonstrates the value of biodiversity in urban contexts.

However, the study struggles somewhat with connecting its findings explicitly to the concept of BGI. BGI is often understood as engineered infrastructure—such as green roofs or rain gardens—designed to improve environmental outcomes in human-made spaces. In this study, however, BGI is framed more broadly, referring to the modification of human-used landscapes to support natural habitats and species. While this is a valid interpretation, the distinction could have been made clearer. Another limitation is the narrow applicability of the findings. Although amphibians are highly sensitive to anthropogenic impacts, results derived from their responses cannot be easily generalized to other species, such as birds or small mammals. This limits the study’s broader ecological relevance.

I personally found this study extremely interesting and eye-opening, particularly in its approach to using natural habitat features as a form of Blue-Green Infrastructure—an area of habitat management I had not previously considered. While this type of infrastructure was new to me, the results confirmed some of my assumptions about regional biodiversity enhancement in cities and also provided surprising insights. I was impressed by the depth of evidence presented, including the various mapping strategies that show cities can increase amphibian connectivity by up to 15% if key habitat features are intentionally incorporated. From this study, I have gained not only a better understanding of BGI but also an appreciation for the optimistic potential cities have to enhance biodiversity when environmental considerations are prioritized in infrastructure planning.

Overall, I found this study to be compelling and thought-provoking, proposing important ideas supported by strong data. While the study is well-executed in terms of methodology and reasoning, it does have some limitations. For instance, certain conceptual elements could have been expanded to make the findings more broadly applicable to other species and urban contexts.

The study effectively conveys its central message: cities can improve environmental conditions and support regional biodiversity if planners actively consider ecological factors in infrastructure design. Nevertheless, the work is far from exhaustive. Future research could explore how these interventions affect other species, such as birds or small mammals, and investigate practical strategies for implementing BGI in existing urban areas. Additionally, examining how cities can retrofit current infrastructure to better support biodiversity would further enhance the study’s practical relevance.

Donati, G. F. A., Bolliger, J., Psomas, A., Maurer, M., & Bach, P. M. (2022). Reconciling cities with nature: Identifying local Blue-Green Infrastructure interventions for regional biodiversity enhancement. Journal of Environmental Management, 316, 115254. https://doi.org/10.1016/j.jenvman.2022.115254

Crowley, S. L., Hinchliffe, S., & McDonald, R. A. (2017). Conflict in invasive species management. Frontiers in Ecology and the Environment, 15(3), 133–141. https://doi.org/10.1002/fee.1471

The introduction and establishment of invasive species are leading causes in global biodiversity loss. These species not only actively outcompete native and endemic species that inhabit similar environments, but can also disrupt and alter their new habitat, completely shifting the ecological dynamics that exist within all components, both biotic and abiotic, of the system. The establishment of an invasive species can cause significant damage to the population of many native species, and can even lead to local and species extinctions.

Invasive species exist within the context of their environments. This means that just because a species may be considered invasive in one area, it is not by default deemed invasive in all locations. Additionally, not all introduced or non-native species are considered invasive. In fact, a majority of non-native and introduced species are not considered invasive to their introduced range. For an introduced species to be considered invasive, it had to produce some sort of harm, generally economically, environmentally, or to human health. This harm can be realized through a multitude of ways, including damaging agricultural fields and crops. Many invasive species have been known to negatively impact agriculture and farmland, costing both farmers and governments hundreds of millions of dollars annually. Additionally, invasive species can negatively impact human health by spreading diseases. An introduced species, acting as a vector, can spread pathogens to numerous individuals, resulting in the spread of both existing diseases and potentially new illnesses. If the introduced vector species fits the criteria of an invasive species, its ability to spread disease would be greater, resulting in an increased infection rate in the human population. This would result in significant economic damage, as governments would be required to develop treatments, medications, and vaccines, and mitigate the impacts of the invasive species. 

These species also disrupt ecological systems and cause significant environmental damage. Invasive species are often extreme generalist species, meaning that they thrive in a large variety of conditions; because of this, these species frequently outcompete native species for resources such as food, nesting locations, growing spaces, etc. Invasive species are also quite efficient at reproducing and spreading, allowing them to further establish and extend their range. These species also cause economic damage this way, as governments will frequently make efforts to combat the impacts of an invasive species once it has been established. These efforts are quite economically intensive and can cost governments millions of dollars.

This study, published by Crowley et al. in 2017, evaluated the patterns in which conflicts arise within invasive species management, as well as identifying some of the more divisive management strategies, and why some of these conflicts arise initially. Sociopolitical issues are a common ignition of conflict, as management strategies have differing impacts on different individuals, communities, and cultures. Another common cause of conflict is the typically used top-down control approach, as this method often fails to recognize the more minute details of the issue; this approach also isolates the general public from the issue, as centralized authorities are making the decisions. Once a conflict has been inflicted, Crowley et al. (2017) suggest that there are two main drivers in accelerating conflict: polarization, often driving discussions to feel black and white, and escalation, which occurs as the conflict and number of involved parties grow. Escalated conflicts are self-perpetuating and can often reach a point where “winning” becomes more prominent than the initial invasive species issue. This study suggests making shifts in our existing invasive species management practices by promoting more openness in communication, placing emphasis on the context of the ecosystem, and fostering early public involvement to generate more productive management strategies. 

Figure 1. 

This study recognises its own complexities by acknowledging that each situation is entirely unique and each of the variables within these situations is unpredictable. It, however, does not offer any solutions for how to account for this variability. Instead, it offers that individuals, when engaged in conflict, tend to behave in predictable ways, allowing researchers to identify these behaviors. One potential avenue for improvement would be to explore the correlation that exists between the number of variables involved in a situation and the unpredictability of the conflict. This would allow researchers to understand more specifically how these conflicts arise and accelerate. Furthermore, this study only briefly considers actual case studies. As a result, we can only consider invasive species management strategies and their consequential conflicts, hypothetically. Due to the constraints of this study, the authors were not able to observe these species and these practices in the field. A future study may benefit by assessing these conflicts and behavior patterns firsthand, with an actively invasive population currently undergoing management practices. Overall conclusions of the study suggest that wildlife managers and officials should put more energy into proactive and anticipatory invasive species management approaches, such as monitoring programs and preventive outreach initiatives. While this would be ideal when it comes to avoiding conflict within invasive species management, as you would have to interact with fewer stakeholders, it does not account for situations in which the invasive species are already established in a new habitat. The article goes on to explain the steps that Crowley et al. (2017) identified one should take in order to minimize the risk of conflict when planning and applying invasive species management strategies; however, I propose a further study that focuses only on established invasive species populations within a given area that are managed in different ways. This study would assess how conflict arises in similar settings, and would offer a more controlled version of the study, allowing us to identify ways to minimize conflict when managing already established invasive species.