Publish perceptions and attitudes toward urban wildlife encounters – A decade of change

Posted on by Ember Madison Miller

Overview: This study assessed the public’s perceptions of urban wildlife in Krakow, Poland and compared it with 2010 data. In a questionnaire, the researchers found that wildlife interactions with wild boars, red squirrels, brown hares, red foxes, and roe deer have increased since 2010. Since urbanization is only increasing, it makes sense that human-wildlife interactions are increasing as well.

Methods: The study area was in Krakow, Poland which is the second largest city in Poland. The Vistula River goes through the city which acts as a natural migration corridor for wildlife. The area consists of green patches, agricultural areas, watercourses, and urban land. The researchers sampled the population of Krakow, with 887 responses observed. The questionnaire consisted of sections that observed the population’s attitudes toward wildlife in the city, attitudes toward managing conflict situations with wildlife, socio-demographic information, encounters with wildlife and their reported behavior, and perceptions of conflictual wildlife and their associated problems. This questionnaire conducted in 2020 was similar to the 2010 questionnaire and statistical differences of the sociodemographic variables between the two years were calculated in ANOVA. Chi-square tests were also conducted to evaluate the differences in wildlife in Krakow and the respondents’ attitudes toward wildlife.

Results: The results showed that the socio-demographic factors between 2010 and 2020 were not significantly different. Results also showed that human-wildlife encounters have increased over the decade, with multiple species being significant.

Wildlife2010 (n)2020 (n)Mean (±SD)χ2p-Value
Red squirrel (Sciurus vulgaris)93791442 (±493.56)551.13<0.001
Hedgehog (Erinaceus roumanicus)601701651 (±70.71)7.680.005
Red fox (Vulpes vulpes)276444360 (±118.79)39.20<0.001
Roe deer (Capreolus capreolus)271409340 (±97.58)28.00<0.001
Wild boar (Sus scrofa)130308219 (±125.87)72.34<0.001
Stone marten (Martes foina)256394325 (±97.58)29.30<0.001
Mute swan (Cygnus olor)490651570.5 (±113.84)22.72<0.001
Bat (Chiroptera)257286271.5 (±20.51)1.540.213
Mallard (Anas platyrhynchos)29703366 (±476.59)620.60<0.001
Brown hare (Lepus europaeus)66344205 (±196.58)188.50<0.001

“χ2: p < 0.05; Bonferroni correction: p < 0.025. Italic: significant in Chi Square test, bold: significant after Bonferroni correction, bold and italic: significant in Chi Square test and Bonferroni.”

Additionally, the behavior of the species also changed from 2010 to 2020. More recently, the respondents found wildlife showing more behaviors (Figure B) other than running away from humans when being encountered like in 2010 (Figure A).

Fig. 1

“Fig. 1. Canonical correlational analysis (CCA) ordination biplot of wildlife (in red) and their reaction while observing residents (blue arrows) as recorded in Krakow in 2010 (A) and 2020 (B). CCA plots to determine the relationship between wildlife and their observed behaviour.”

The researchers also found that the participants agreed that the most conflict causing species included the roe deer, stone marten, red fox, and wild boar. (Figure A = 2010, Figure B = 2020) The number and types of nuisance wildlife proved to be significantly different.

Fig. 2

Lastly, the attitudes of the public were mostly neutral (36%), with around 25% of people being negative and 23% being positive. They found that there was a significant difference in the attitudes of the public between 2010 and 2020.

Critiques: Although this paper was pretty straight forward, I do wish that they mentioned the 2010 data of the public’s overall attitudes like they did with the 2020 data. Additionally, they mentioned in the limitations section that their selection of the participants was not completely random, and that there was only 23% of men representation. I do think picking a better selection of the participants would have been better for a more accurate representation of the Krakow population. Other than that, I did find it interesting to see how human-wildlife encounters have changed from 2010. I think this paper could help wildlife managers understand the public opinion in Krakow in order to inform possible management strategies.

References: Basak, S. M., Hossain, Md. S., O’Mahony, D. T., Okarma, H., Widera, E., & Wierzbowska, I. A. (n.d.). Public perceptions and attitudes toward urban wildlife encounters – a decade of change. ADS. https://ui.adsabs.harvard.edu/abs/2022ScTEn.83455603B/abstract 

Political polarization of conservation issues in the era of COVID-19: An examination of partisan perspectives and priorities in the United States

Posted on by Trent Ford

This study was conducted to examine the effects of the COVID-19 pandemic on conservation issues among adults with different political affiliations, as well as to determine the relative importance of these issues across the political spectrum. Additionally, it looked to understand how these issues coalesced during the 2020 US general election. It is crucial to determine the changes in the polarization on this broad category of issues because out of 14 major policy issues listed to voters in the study, conservation issues such as endangered species conservation and control of zoonotic disease ranked very low; Even lower than climate change.

The researchers used Qualtrics surveys and distributed them to 1,560 residents in August 2020. The study had quotas for how many respondents they used by state, age, and political affiliation. These political affiliations were assigned the following strata: Conservative Republican, Liberal/Moderate Republican, Independent/Other, Moderate/Conservative Democrat, and Liberal Democrat. Respondents were asked a series of 14 policy questions, with 12 being “standard” policies such as immigration and abortion, and 2 environmental questions. Their answers were on a 5-point scale, with answers ranging from “Not important at all” to “Very important to my vote”.

Researchers found that polarization was highest among the farthest fringes of political ideologies, with the most drastic differences between those who considered themselves furthest right and furthest left. The study found that Democrats experienced positive changes in their opinions (the pandemic made them more favorable to conservation), while Republicans had an adverse change in their views (the pandemic made them less favorable to conservation).

To improve this study, I would have liked to see the changes over a temporal scale represented. For example, the study could have sent Qualtrics surveys to respondents once in 2019 and compared the changes in the resurvey conducted in August 2020. This would have allowed researchers to directly compare individual changes as well as changes in self-reported political affiliations over the course of time. Overall, however, the results showed substantial management implications for state agency workers creating policy as well as lawmakers looking to represent their constituents better.

Casola WR, Beall JM, Nils Peterson M, Larson LR, Brent Jackson S, Stevenson KT. Political polarization of conservation issues in the era of COVID-19: An examination of partisan perspectives and priorities in the United States. J Nat Conserv. 2022 Jun;67:126176. doi: 10.1016/j.jnc.2022.126176. Epub 2022 Mar 26. PMID: 35370533; PMCID: PMC8957370.

https://pmc.ncbi.nlm.nih.gov/articles/PMC8957370/#ab010

A Critical Review of: “Are British urban foxes (Vulpes vulpes) “bold”? The importance of understanding human-wildlife interactions in urban areas

Posted on by Alexandria Helena Lupton

The process and expansion of urbanization is becoming an increasingly prevalent issue across the globe. Among the list of problems increased human-wildlife interactions creates, interactions with carnivores are one of the more serious. Some groups of carnivores, such as coyotes and red foxes, have begun to adapt their behaviors to better coexist with humans, whether that be through self-domestication or a more simple symbiotic relationship. However, the long term consequences and cascading effects of these new behaviors is unclear.

One British study published in 2020 focused on the red fox (Vulpes vulpes) and their potential changes in behaviors of neophobia (fear of new things, or level of curiosity) and overall wariness of new and changing environments. The study notes that many British news articles and journals have discussed public discourse with the increase in red fox populations within their yards and common spaces, describing the canids as “bold.” However, they also explain that by continuing stereotypes of foxes being “sly” and “cunning,” it completely disregards the personalities that foxes (and many other animals) display, and causes more public issues in the long run. 

While this study is highly qualitative and variable based on scientists’ opinions, the methods for the study created very quantitative and concrete results. The mapping of the study area for six urban fox groups was tested through both radio-tracking and camera traps to identify the foxes’ territories and boundaries.

After firm boundaries for each group of foxes was determined, many smaller experimental areas were created in randomly selected gardens/yards within sparsely populated suburban areas. These areas were small circles cut into the lawns, divided into 4 quadrants: quadrant 3 facing the house, quadrant 1 being closest to the entry of the lawn (for the foxes), and quadrants 2 and 4 facing the sides of the yard. 

While results were conducted in batches to test seasonality (late November-early December 2014 and May 2015), the seasonality ended up not impacting the overall data (null). The recording equipment was to help provide identification of individual foxes (for personality and behavioral details) and for testing how curious foxes were based on the quadrants and areas they explored, in addition to a new or foreign object. To test wariness behaviors (“a response to a potentially threatening stimulus”), the study used garden twine that had been soaked in wolf urine. Figure 6 shows the placement of the foreign object in orange (neophobia test), and the placement of the urine soaked twine in blue.

The results were determined by how quickly the foxes would get to the food hidden with the new object, overcoming their neophobia, and the wariness related to the urine-soaked twine (all behaviors before and after this process were noted as well). The behaviors were described by specific standards and parameters as shown in table 2:

The overall results from both seasons of the study, with 2,127 visits from foxes, the classified “dominant” foxes were shown to have made more visits to the circle and quadrants than “subordinate” foxes. However, the dominant foxes would not explore nearly as much as subordinate foxes, leading to the conclusion that there is a strong relation between personality and neophobia and wariness. Additionally, while most of the visits were from foxes that were alone, these solitary fox visits also showed significantly more present behaviors of both neophobia and wariness, in comparison to foxes who visited the sites in groups. 

This data shows that the increased fox presence (or “nuisance” as depicted by public articles), is possibly being artificially selected for because of the availability of food, as many as 1 in 7 people put food out for the foxes. While the small complexities and details of fox personality and behavior were unable to be explored in this study due to scope and time, it opens the way for more understanding between human and fox populations. Especially in a time when more and more wildlife habitat is being encroached upon, finding ways to mesh big social and personal differences between species will become increasingly necessary. Conclusively, more research needs to be done on the intricate communities and the entire social network that occurs both with and without human intervention/interaction. This way, we can both reduce human-wildlife interactions and reduce the negativity explored by preconceived expectations and notions of various wildlife species.

Padovani, R., Shi, Z., & Harris, S. (2020, December 26). Are British urban foxes (Vulpes vulpes) “bold”? The importance of understanding human-wildlife interactions in urban areas. Ecology and Evolution, Volume 11, Issue 2, Pages 835-851, https://doi.org/10.1002/ece3.7087 

Urbanization and the Ecology of Wildlife Disease: Summary and Analysis by Sophia Skinner

Posted on by Sophia Isabella Skinner

This study focuses on the impact that urbanization and human interactions have on the gut microbiome of wildlife. These animals that come into contact with humans have shown that they have differences in their microbiome, rather than other animals of the same species that are deep in the woods with no human contact. The process of animal microbiomes becoming more like people’s is called “humanization” of their microbiome. This is a very important factor when studying human-animal interactions in urban areas, because these distinct changes are indicators of urbanization.

The research performed in this study was done on 3 different animals: anoles, coyotes, and sparrows. These animals were tested in both urban and rural areas around the world. Some samples were taken from Puerto Rico, some were from California, and others, like Venezuela or Cameroon. The diversity of the animals and places reduced the amount of bias and error that the results would show. The more diverse the location and the species of animal, the more reliable the data. To compare the animal microbiota findings, the researchers compared these microbes to humans. The more similar they were to humans, the more humanization that occurred in the animal’s microbiome.

The results of the research showed that the closer an animal lives to an urban area, the more their microbiome reflects humans. The closer animals were to humans, the more human-associated bacteria there were in their gut. This clear shift in microbiome contents between wildlife coming into contact with urban areas/cities versus wildlife that lives in the wild indicates a clear humanization of microbiomes in animals.

Some changes or improvements that I would make for next time would be to look into more of the causes of why humanization occurs, rather than focus on whether or not it occurs. With this research, we know that it does happen, but I think it would be of better use to know where it stems from. For example, do animals that eat human trash have an increased number of human-associated microbes? Is that the number one cause of humanization of animal microbiomes? If not, then what is? Though it is important to know that humanization of microbes exists, I think the next area of research needs to focus on how animals are at an increased risk of exposure to human microbes, as well as how that impacts them.

Citation: Dillard, B. A., Chung, A. K., Gunderson, A. R., Campbell-Staton, S. C., & Moeller, A. H. (2022). Humanization of wildlife gut microbiota in urban environments. eLife, 11, e76381. https://doi.org/10.7554/eLife.76381

The importance of ponds for the conservation of bats in urban landscapes

Posted on by Michael John Rejzer

Overview

The article that I chose to review is “The importance of ponds for the conservation of bats in urban landscapes” by Ancillotto et al. (2019). The study presented in the article discusses research into the importance of urban ponds and how certain qualities can shape how effectively different bat species can survive in their presence. Bats are a vital species when aiding in insect control around urban areas and while many species are heavily impaired in urban environments, there are still those that thrive in these conditions.

The goals of this study were to find how strongly differing levels of vegetation surrounding the ponds had an effect on bat populations. They also sought to record how the surrounding landscape and artificial light presence had a selective impact on bat species. These questions focused on how well bats can feel comfortable avoiding predators in an urban environment as well as how beneficial an area is to their own feeding techniques. These bats rely on lentic habitats for their high water intake so ensuring the area is suitable for preying upon insects is vital to their survival in an urban environment.

Methods

The study was taken place in the municipality of Rome across 35 selected ponds. These ponds were selected to ensure the study encompassed varying pond sizes, riparian vegetation, natural or manmade banks, and surrounding land cover. The ponds were found via satellite images and were only considered if they contained a water surface that was level with the surrounding ground, a perennial history, open air to allow bat access to the pond, the pond was not connected to any other bodies of water, and the water surface was free from vegetation. The ponds’ origins did not have any effect on their selection and for all ponds chosen there were pond management practices taken at least 2 years before the study.

For bat sampling, activity was recorded between June and September 2016-2017. Samples were taken four hours after sunset and only once per site. A manually operated Pettersson D1000X bat detector was used at each site and sampled at a frequency of 384 kHz. Recordings were taken along the banks of each site where there were no obstacles or noises that could block or interfere with readings. Weather and moon illumination were also taken into account when deciding on when to perform sampling events. From here, bat species were identified by their echolocation calls and the most abundant species was used for analysis of bat activity. Bat activity was quantified as bat passes per night with bat passes being counted with 2 or more echolocation calls.

For the second part of the experiment, the landscape and environment was estimated within 50m, 200m, 1000m, and 3000m radii of circular areas around the sampling point. Each distance aided in measuring different categories of environmental features from local to much more broad features of the area. Habitats were to be classified as urban matrix, woodland, open green areas, or intensive farmland. Finally, distance between the pond and other important features was also taken to aid in statistical analysis.

Environmental variableDescriptionUnit
woodland1000Amount of woodland habitat types in a 1000 m radius around sampling pointPercentage
perimeterMeasure of pond perimeter – a proxy of riparian habitat availabilityMetres
bank typeClassification of riparian habitat as natural (>75% covered in vegetation) or artificial (>75% made of concrete) – proxy of riparian habitat qualityCategorical
distmarginDistance between sampling point and closest vegetation edge (hedgerow, tree line, woodland margin)Metres
distbuildingDistance between sampling point and closest buildingMetres
distlightDistance between sampling point and closest artificial nocturnal lightMetres
green50Amount of open green areas (open spaces not including patches of woody vegetation such as natural grasslands, recreational green areas, non-intensive farmland, orchards, private vegetable gardens, small organic farms) in a 50 m radius around sampling pointPercentage
green200Amount of open green areas (open spaces not including patches of woody vegetation such as natural grasslands, recreational green areas, non-intensive farmland, orchards, private vegetable gardens, small organic farms) in a 200 m radius around sampling pointPercentage
green1000Amount of open green areas (open spaces not including patches of woody vegetation such as natural grasslands, recreational green areas, non-intensive farmland, orchards, private vegetable gardens, small organic farms) in a 1000 m radius around sampling pointPercentage
green3000Amount of open green areas (open spaces not including patches of woody vegetation such as natural grasslands, recreational green areas, non-intensive farmland, orchards, private vegetable gardens, small organic farms) in a 3000 m radius around sampling pointPercentage

Results

Of the 2317 recorded bat passes, 94.4% belonged to the species Pipistrellus spp. and Hypsugo savii. The most common bat species that was found at all recorded sites was the P. kuhlii and had a total of 1049 bat passes. The results found from environmental data in addition to this species showed a positive relationship between the bats and the amount of bank habitat alongside the ponds. Another feature that was found to be important was the existence of natural banks over artificial ones. Bats were generally found to be more active around ponds with a majority of natural banks rather than those that were dominated by artificial banks. Distance from the closest building also had a consistently positive effect while distance from closest streetlamp light had varying effects from positive to negative depending on the species. This aids in the notion of how different bat species using different hunting techniques which can be harmed or helped by the presence of light. The amount of open habitat had a varying effect throughout the different species at different ranges while woodland habitat within the 1000m radius was found to have an overall positive effect.

ResponseModelAICcΔAICckw
Species richnesswoodland1000121.970.0010.55
woodland1000 + perimeter123.021.0520.02
Total bat activityperimeter + distmargin + woodland1000337.710.0030.65
perimeter + distmargin + woodland1000 + distbuilding338.881.1740.36
Pipistrellus kuhliiperimeter + distlight + distmargin + woodland1000286.590.0040.66
perimeter + distlight + distmargin + woodland1000 + green1000288.441.8550.15
Hypsugo saviiperimeter + distbuilding + distmargin248.850.0030.75
perimeter + distbuilding + distmargin + green50249.450.6040.30
perimeter + distbuilding + distmargin + green50 + bank type249.600.7550.28
Pipistrellus pipistrellusbank type + distmargin236.44020.63
bank type + distmargin + perimeter237.310.8730.59
bank type + distmargin + perimeter + green3000238.331.8940.11
Pipistrellus pygmaeusdistlight + bank type + woodland1000 + perimeter + distmargin171.51050.49

Critiques/Reflection

As a study, I found this to be an interesting topic to have questions about. Bats have always seemed to me as a species that readily benefits humans as they are a pest control species. One feature I liked about the article was its discussion on how light posed as a detriment to many species of bats while it could prove advantageous to others. The article did discuss how the light was useful in attracting prey and dangerous for revealing bats to predators but it did not give specifics as to why some bats choose to risk it. If there were to be any improvements there I would add what sort of adaptation or improvement some bats have that allows them to make use of well lit areas and reap the benefit of increased food.

For areas that could be expanded upon, the article did a great job at listing other variables that were not included but should be referenced in future studies. One example includes how water quality might have an effect on a pond’s popularity with bats. Since bats use ponds as one of their primary drinking sources, it is important to study what kind of water pH or quality they prefer. This can then be used to determine what water management practices should be taken for urban ponds as well as the vegetation that surrounds them.

A point I would like expanded is the idea that certain ponds might need to focus on benefitting one species over others. In this study, the results were compared to the preferences of the most common species. What if we should then be focusing our efforts on what the minority of species needs to survive? With expanding urbanization, the problems held by those bat species in the minority will only spread and expand their struggles with survival. To properly ensure the protection of all bat species in an area some ponds may need to be specialized to favor certain species over those who have more generalized needs.

While the essay could always be improved by adding more variables to future studies, the authors do a great job in addressing where there is lacking information and next steps that could be taken to improve further.

Reference

L. Ancillotto, L. Bosso, V.B. Salinas-Ramos, D. Russo, The importance of ponds for the conservation of bats in urban landscapes, Landscape and Urban Planning, Volume 190, 2019, 103607, ISSN 0169-2046,
https://doi.org/10.1016/j.landurbplan.2019.103607.

Canada geese (Branta canadensis) nesting on elevated structures in urban Indiana, USA

Posted on by Caleb John McCabe

Background and purpose: As Canada goose populations have recovered from near extirpation to approximately 113,000 individuals in Indiana over the past 60 years, urban densities have created persistent human-wildlife conflicts and novel behavioral adaptations. Canada geese typically nest on the ground or slightly elevated natural sites like muskrat lodges near water bodies. However, the effects of urbanization on nesting site selection in this species have been understudied. This article documented observations of Canada geese nesting on rooftops 2.6–12.2 meters above ground level in central Indiana to understand how urban environments are influencing nesting behavior in this adaptable waterfowl species.

Methods: Researchers conducted routine nest surveys across three study areas in the Indianapolis Metropolitan Area from March to July 2021. Five rooftop nests were discovered and monitored on a weekly basis. Data collection included capturing band information from adult geese, counting eggs, recording nest materials, and tracking nest success through observations of egg membranes and goslings. Nest characteristics such as height above ground, distance to nearest water body, clutch size, and construction materials were documented. Hatching success was compared between elevated nests and ground-level nests in the same study areas.

Results: Rooftop-nesting Canada geese showed distinct differences from traditional ground nesters. Elevated nests had significantly smaller clutch sizes (average 4.00 eggs) compared to ground nests (5.01 eggs), but achieved 100% hatching success versus only 59.9% for ground-level nests. This suggests that while elevated nesting may reduce reproductive output, it significantly improves nest survival. Nest construction materials differed substantially, with rooftop nests using atypical materials like automotive belts, plastic sheets, and loose gravel with minimal traditional down and body feathers. All five rooftop nests successfully hatched, though goslings from two nests required human rescue due to barriers preventing natural departure. The researchers hypothesize that geese are selecting these elevated sites to avoid ground predators including mammals and human disturbance.

Criticisms: This study provides valuable documentation of an emerging urban adaptation, but several limitations affect the strength of conclusions. The sample size of only five nests is quite small for making broad generalizations about population-level behavioral changes. The study lacks systematic methodology for nest discovery, so it’s unclear whether these represent rare occurrences or a more common behavior that’s simply underreported. I would be interested to know if the researchers were actively searching for rooftop nests or if they just happened upon them during other surveys. Additionally, the research provides no data on long-term gosling survival rates after hatching, which is crucial for determining whether this apparent nesting advantage translates to reproductive success. While hatching success was high, the fact that goslings from two nests required rescue suggests potential survival challenges that could offset the benefits. 

The study also lacks environmental controls such as temperature measurements comparing rooftop versus ground conditions, which could help explain the higher hatching success. I am curious whether this behavior is spreading to other regions or if it represents a local adaptation specific to central Indiana’s urban landscape. Future research would benefit from larger sample sizes across multiple urban areas and longitudinal tracking of gosling survival rates to determine the true fitness consequences of this behavior.

Reference:

Shearer, D. J., Carter, T. C., & O’Neal, B. J. (2022). Canada geese (Branta canadensis) nesting on elevated structures in urban Indiana, USA. Ecology and Evolution, 12(3), e8735. https://doi.org/10.1002/ece3.8735

Effects of Urbanization on Cougar Foraging Ecology Along the Wildland–Urban Gradient of Western Washington

Posted on by Madeleine Elisabeth Rueckeis

Background and purpose: As urbanization grows, the overlap between cougar and human populations increases. Large carnivores are highly susceptible to habitat modification, because they tend to have low population density and wide ranging travel for their food requirements. The effects of urban development on the way cougars forage has rarely been studied and researched. This article investigated variation in cougar use of three prey types (synanthropes, ungulates, and rodents) along a wildland–urban gradient in western Washington to determine how urbanization affects the foraging ecology of this apex predator.

Methods: This study used trained dogs and cage traps to capture and radio-tag cougars throughout the 4450km^2 study site. They did this from 2004-2008 and again from 2013-2016. Once captured the animals were immobilized and given a physical examination and outfitted a GPS radio collar. Kill sites were located and prey identified. The surrounding urbanization of kill sites was measured as building density (structure per hectare). The diets of twenty individual cougars and their 568 kills were analyzed using statistical models.

Results: Firstly synanthropic prey use increased and odds of cougars preying on synanthropes (animals living in close association with humans) rose nearly fivefold with each additional building per hectare. However, only certain individual cougars specialized in synanthropes. Black-tailed deer and elk did remain the dominant prey throughout. Cougars remained to rely on ungulates as prey, which suggests that predator-ungulate systems can survive near human settlements. Additionally, as building density increased, kills of beaver and mountain beaver decreased, likely due to habitat loss and management practices reducing rodent presence. And it was also discovered that male cougars hunted rodents more often than females. Lastly, the study showed that some cougars deviated extensively in prey choice. For example, one male accounted for half the rodent predation.

Criticisms: Overall I thought this study was an insightful and interesting read. The research did have some limitations however. For one, building density was the only measure of urbanization, which oversimplifies the the complexity of human disturbance. Furthermore, the difference in collar technology between study periods may also have affected kill detection, making temporal comparisons less reliable. The lack of direct data on prey abundance makes it difficult to analyze whether dietary preferences of the cougar was a result of prey preference or prey abundance. Lastly, the limited sample size of twenty cougars makes it hard to apply this data across populations. Individual variation most likely strongly influenced results, especially if one male accounted for half the rodent kills. Future work could benefit from combining prey availability survey with kill site data to distinguish between preference and availability. Additionally standardized tracking technology, multiple measurements of urbanization, and a broadened sample size would yield more thorough results.

Reference:

Robins, C. W., Kertson, B. N., Faulkner, J. R., & Wirsing, A. J. (2019). Effects of urbanization on cougar foraging ecology along the wildland–urban gradient of western Washington. Ecosphere, 10(3), e02605.https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecs2.2605

Bat Activity in an Urban Landscape: Patterns at the Landscape and Microhabitat Scale

Posted on by Jada L Lee

Overview

The article that I am reviewing is “Bat Activity in an Urban Landscape: Patterns at the Landscape and Microhabitat Scale” by Gehrt and Chelsvig (2003). This study addresses an important and often overlooked question in urban ecology: how do bats respond to increasing urbanization, and to what extent do both large-scale (landscape-level) and fine-scale (microhabitat) features influence their activity? Bats play a crucial ecological role as insect predators, yet research on their persistence in urban and suburban environments has historically lagged behind studies of more visible species.

The authors sought to answer two primary questions. First, they inquired about how landscape-scale variables, such as the proportion of forest cover or urban development, influence overall bat activity. Second, they examined whether microhabitat characteristics, including canopy cover, presence of water, and local vegetation structure, explain additional variation in bat activity beyond what can be predicted by landscape context alone. Together, these questions aimed to shed light on how bats navigate increasingly fragmented urban environments and what habitat elements are most critical for their persistence.

Methods

To investigate these questions, the researchers conducted acoustic surveys across multiple sites representing a gradient of urbanization. Ultrasonic bat detectors were used to record echolocation calls, which served as an index of bat activity. The study design incorporated two spatial scales of analysis. At the landscape scale, the researchers quantified features such as forest cover, urban development, and impervious surface area surrounding each site. At the microhabitat scale, they measured local site variables including canopy density, vegetation structure, and proximity to water.

Data collection took place during the summer months to coincide with peak bat activity. The researchers then analyzed bat “passes” (recorded calls) to determine how strongly activity correlated with both landscape and microhabitat variables, allowing them to separate broad-scale effects from those operating at the site level.

Results

The results revealed a clear pattern: bat activity declined as the amount of urban cover increased and was positively associated with forest cover. This suggests that bats are sensitive to habitat loss and fragmentation at the landscape level. However, the study also found that microhabitat features significantly influenced bat activity even within similarly urbanized areas. Sites with dense tree canopy, well-developed vegetation structure, and water sources exhibited higher activity than sites lacking these features.

These findings demonstrate that landscape context and local habitat quality interact to shape bat distributions. Two sites with comparable levels of urbanization could display markedly different levels of bat activity depending on their microhabitat composition. This means that conserving or restoring key habitat elements at the local scale can have a meaningful impact on maintaining bat populations even within urban settings.

Critiques and Reflection

This study is commendable for highlighting that both large-scale and fine-scale habitat features must be considered when developing urban wildlife management strategies. Its reliance on acoustic monitoring was also useful, as it provided a non-invasive yet comprehensive method for assessing bat presence and activity across numerous sites. Furthermore, the study’s findings carry clear implications for urban planning, suggesting that preserving forest patches, maintaining tree canopy, and protecting water bodies can promote bat activity in otherwise developed landscapes.

Nevertheless, there are areas in which the study could be strengthened. The analysis aggregates overall bat activity rather than distinguishing among species or foraging guilds, which may obscure species-specific responses to urbanization. Some species may be more tolerant of urban settings than others, and identifying these differences would help refine conservation priorities. Additionally, the study’s temporal scope is limited; sampling across multiple seasons or under varied environmental conditions could reveal whether the observed patterns are consistent year-round. Finally, the article could have offered explicit management recommendations, such as quantifiable targets for canopy cover or patch size, that would be useful for city planners and conservation practitioners.

Despite these limitations, the study contributes meaningfully to urban ecology by illustrating that microhabitat improvements can mitigate some of the negative effects of urbanization on bats. It challenges the notion that urban areas are inherently unsuitable for wildlife and underscores the importance of intentional habitat design in cities.

Reference

Gehrt, S.D. and Chelsvig, J.E. (2003), BAT ACTIVITY IN AN URBAN LANDSCAPE: PATTERNS AT THE LANDSCAPE AND MICROHABITAT SCALE. Ecological Applications, 13: 939-950. https://doi.org/10.1890/02-5188

Black Bear foraging behavior in urban landscapes

Posted on by Claire Elyse Rusconi-Warner

Background:

Black bears require a very high caloric intake leading up to the cold months when hibernate. They depend on a decent yield of soft and hard mast production in order to reach these nutritional needs, but sometimes hard or soft mast yields may drop too low to sustain Black bear populations. When this happens, bears need to forage for alternate food sources. Urbanization has been rapidly increasing which alters what these Black bear populations are exposed to. Being highly adaptive creatures, Black bears have come to use human garbage as an alternate food source. For urban bears, garbage can be easily accessed and can be high in calories.

This study was conducted in order to understand their foraging ecology in urban landscapes. The goal of the research is to find better solutions to mitigate human-wildlife conflict with Black bears.

Methods:

This study was conducted in the urban areas of Aspen, Colorado. During the months of May-August, researchers captured bears and fitted them with radio collars that were programed to report the bear’s locations every 30 minutes between May-September. From 2007-2010, researchers tracked 40 bears during May-September, which is their active season in Colorado. They backtracked to bear locations then inspected the area to see whether there is evidence of natural or anthropogenic foraging evidence. The area they would search at each back-tracked location had a 20 meter radius. They remotely downloaded data and backtracked to the most recent 24 hours of location data. They did not backtrack to the most recent location in order to avoid disturbing the bears, and they only used locations that were within 50 meters of a building.

Natural foraging evidence included animal carcasses, broken foliage, turned over rocks, ect. Anthropogenic foraging evidence included scattered garbage, visual observations of people present, broken limbs on landscape trees, broken windows, ect.

They used the backtracking data to summarize spatial and temporal patterns of the bears on natural and anthropogenic food sources.

Results:

Prehyperphagia refers to the months of May-July. Hyperphagia is when bears greatly increase their food intake prior to winter, during the months of August-September. Garbage was by far the most highly used anthropogenic food source. While garbage was consumed in high amounts every year, the poor years (years when less natural food sources were available) accounted for much higher levels of garbage consumption. The amount of garbage consumed during Hyperphagia was 5 greater during poor years.

The researchers randomly sampled 384 garbage containers and found that 76% of them were bear-resistant, but only 57% of the bear-resistant containers were properly secured.

Discussion:

The researchers determined that Black bears are most driven by cost vs reward when foraging. They put in the least amount of effort for the highest amount of caloric intake. They determined that the best next action is to decrease the reward bears receive when foraging in garbage, or increase the amount of effort put in. That would hypothetically steer bears towards foraging in wild land areas more often.

Critiques and takeaways:

Overall, I found the methods of this study to be fairly reliable in reducing potential bias and effectively answering the research question. The researchers were able to analyze 2 good years and 2 bad years. They were able to follow a decent sample size of bears, and collect data from a high number of feeding locations. They did, however, not dive deep into the dynamics within the wild land areas surrounding Apen, Colorado. This makes sense since the purpose of this study was to find answers specific to urban Black bear foraging behavior. This does raise a couple of questions that could aid in the understanding of urban Black bear foraging behavior though. Mostly, I think it’s worth researching Black bear population dynamics in the surrounding wild areas. Are these urban bears only urban because they are being pushed out of natural spaces by more dominant bears? Is there a lack of food sources available to sustain the whole Black bear population in these areas? How does hunting or a lack thereof play into the need for bears to travel into urban areas? To what degree are Black bears bothered by entering urban areas, and how bad do the alternatives need to be to push them there?

Those are a lot of questions, but I think it would be very interesting to conduct research that could answer some of these questions in wild land locations surrounding Aspen, Colorado in order to best relate results to one another.

Article:

URL: https://esajournals.onlinelibrary.wiley.com/doi/full/10.1890/ES15-00137.1

Citation: Lewis, D. L., S. Baruch-Mordo, K. R. Wilson, S. W. Breck, J. S. Mao, and J. Broderick. 2015. Foraging ecology of black bears in urban environments: guidance for human-bear conflict mitigation. Ecosphere 6(8):141. http://dx.doi.org/10.1890/ES15-00137.1

Urban and Suburban Deer Management by State Wildlife-Conservation Agencies

Posted on by Clay Sebastian

Overview

The title of the paper I will be reviewing is “Urban and Suburban Deer Management by State Wildlife-Conservation Agencies.” The primary reason this study was conducted is because of increasing populations of white-tailed deer in urban and suburban areas throughout the United States. Human-wildlife conflicts have increased as a result of this population growth, which has led to the implementation of various deer management strategies in urban areas. These strategies can either be lethal or nonlethal. Some examples of urban management strategies are bow hunting, firearm hunting, contraception, sharpshooting, trap-and-relocate, and trap-and-kill. There are significant amounts of data available regarding public opinion of various deer management methods in urban areas. However, there has been little effort to understand the management techniques that are preferred by wildlife biologists at state agencies. This study focused on two primary goals. The first of these was to determine what deer management techniques are currently being used by state conservation agencies, their perceived efficacy, and their legality. The second goal was to identify possible drivers for differences in opinions between deer biologists and the general public. 

Methods

The primary method of data collection used in this study was an online survey that was provided to deer biologists who worked at state wildlife agencies. The survey was sent to 41 different state agencies, and 34 of these agencies provided a response. The survey included 10 questions to be answered by deer biologists. These questions mainly focused on the management techniques currently being used in each state, their level of effectiveness, reasons for managing deer populations, and the legality of management techniques. 

Results

The results from this survey were informative for providing answers to the questions being answered by this study. The majority of states indicated that their urban/suburban deer populations were increasing, and the majority of deer biologists believed that urban/suburban deer populations were an issue in their state. One interesting finding was that 64.7% of deer biologists have not done any surveys of local communities regarding their opinions on urban/suburban deer management. The most popular and effective management techniques according to deer biologists were archery hunts, sharpshooting, and firearm hunts. The least popular methods according to deer biologists were trap-and-kill, contraception, sterilization, and trap-and-relocate. The legality of the previously mentioned methods is an influential factor for determining how much they are used in certain states. The vast majority of deer biologists indicated that the primary reasons for management of urban/suburban deer populations were deer-vehicle collisions and damage to gardens. Other popular reasons for management were native vegetation damage and agricultural damage due to deer populations. Additionally, 88.2% of states concluded that the current management of urban/suburban deer populations in their state was effective. 

Critiques/Reflection

This study was able to collect valuable information regarding the opinions of deer biologists on managing urban/suburban deer populations. Although deer biologists and the public commonly agree on the reasons for managing these deer populations (car collisions and garden damage), they have not been able to reach a consensus on the methods that should be implemented. The public is typically not heavily involved with decision making regarding urban deer management policies. This was shown in the survey results since 64.7% of state deer biologists have not made the effort to survey communities about their opinions on deer management. This study could be improved by asking an additional question relating to public opinions. Instead of simply asking if public opinion surveys had been conducted in each state, the questionnaire should have also asked for the reasoning behind this decision. If the state agencies chose not to involve public opinion when making decisions on urban/suburban deer management, then it would be valuable to know why this was the case. There could be a variety of reasons (lack of funds, lack of public interest, inability to reflect public opinion in policies, etc.) for not surveying public opinions, but this study does not provide data to answer this question.

Another suggestion to improve this study could be to modify the methods used for data collection. Overall, there was a high response rate to the survey that was sent to the state wildlife agencies. Although many of the agencies responded to the survey, increasing the amount of data collected would increase the reliability of the study’s findings. This study chose to send the survey in an email and then send a reminder email two weeks after the first email was delivered. I believe that choosing to send the reminder email was a beneficial idea, however, I think that this could be improved. Instead of solely communicating with the wildlife agencies through email, I think that the researchers should have made phone calls to the state wildlife agencies that had not responded to the survey. The agencies could have overlooked the email, or they may not have been certain about the legitimacy of the survey. By making a phone call to the agency, the researchers could have made a more personal connection to the deer biologists who work there. This could have led to higher response rates to the survey, which would have led to larger amounts of data being available to analyze for the study. 

Reference

Rachael E. Urbanek, et al. “Urban and Suburban Deer Management by State Wildlife-Conservation Agencies.” Wildlife Society Bulletin (2011-), vol. 35, no. 3, 2011, pp. 310–15. JSTOR, http://www.jstor.org/stable/wildsocibull2011.35.3.310. Accessed 11 Sept. 2025.