Urban Wildlife and Damage Management

Contributed Oral

Early-Life Experience with Urbanization Influences Departure and Transience Behavior in Coyotes
Emily Zepeda

Natal dispersal plays an important role in connecting individual animal behavior with
ecological processes at all levels of biological organization. As urban environments are rapidly
increasing in extent and intensity, understanding how urbanization influences these long distance
movements is critical for predicting the persistence of species and communities. There is
considerable variation in the movement responses of individuals within a species, some of which
is attributed to behavioral plasticity which interacts with experience to produce interindividual
differences in behavior. For natal dispersers, much of this experience occurs in the natal home
range. Using data collected from VHF collared coyotes (Canis latrans) in the Chicago
Metropolitan Area we explored the relationship between early-life experience with urbanization
and departure, transience, and settlement behavior. Additionally, we looked at how early-life
experience with urbanization influenced survival to adulthood and the likelihood of experiencing
a vehicle-related mortality. We found that coyotes with more developed habitat in their natal
home range were more likely to disperse and tended to disperse farther than individuals with
more natural habitat in their natal home range. Interestingly, our analysis produced mixed results
for the relationship between natal habitat and habitat selection during settlement. Finally, we
found no evidence that early-life experience with urbanization influenced survival to adulthood
or the likelihood of experiencing vehicular mortality. Our study provides evidence that early-life
exposure influences dispersal behavior; however, it remains unclear how these differences
ultimately affect fitness.

Large-Scale Evaluation of a Sodium Nitrite Toxic Bait for Wild Pigs
Nathan Snow, Justin Foster, Michael Lavelle, Justin Fischer, Michael Glow, Seth Cook, Alix Messer, Kurt VerCauteren

Toxic baiting of wild pigs (Sus scrofa) is a potential new tool for population control and damage reduction in the US. Pilot studies for testing a sodium nitrite (SN) toxic bait (HOGGONE 2® containing 5% SN) revealed high efficacy for wild pigs (>90%), but some non-target hazards from wild pigs spilling toxic bait outside of wild pig-specific bait stations occurred. Incorporation of a frightening device, though, successfully alleviated those hazards by deterring non-target animals from consuming spilled bait until operators arrived and mitigated the hazard. Based on those preliminary results, we conducted a large-scale study during the summer of 2021 in northcentral Texas and southcentral Alabama to further evaluate the efficacy and hazards of a SN toxic bait. We attached GPS collars to ~60 wild pigs and ~20 raccoons (Procyon lotor) and Virginia opossums (Didelphis virginiana) during May and June 2021. We deployed toxic bait for up to three nights during July and August 2021 and conducted systematic transects to locate dead wild pigs and any non-target animals. Results will be submitted to the US Environmental Protection Agency as part of a registration application for HOGGONE 2, and will be discussed during this presentation.

Assessing the Influence of Urbanization on a Kin-Structured Passerine, the Black-Crested Titmouse
Rebekah Rylander, Andrea Aspbury, Butch Weckerly, Randy Simpson, Michael Patten, Sarah Fritts

Urbanization is altering avian behavior and survival by depleting natural resources, introducing non-native predators and competitors, and decreasing dispersal corridors. Depending on life-history traits and behavioral plasticity, populations may adapt, emigrate, or suffer declines. To assess the influence of anthropogenic landscapes on avian home range, dispersal patterns, and body condition, we compared populations of a kin-structured passerine, the black-crested titmouse (Baeolophus atricristatus, hereafter BCTI) between urban and rural areas of San Marcos, Texas. We color-banded and monitored urban BCTI families (n = 35) between 2017 – 2019. Urban BCTI home range size was (mean ± SD) 9.11 ± 5.06 ha and was positively correlated with the proportion of high urbanization (areas dominated by impervious cover) within the home range (P < 0.01). Limited dispersal (when juveniles establish a territory adjacent to their father’s) was negatively influenced by the proportion of low urbanization habitat (areas of non-industrial infrastructure and some impervious cover) (P = 0.02), as well as by sex (P = 0.02) and mass-rank (95% CI = [0.21 – 1.28]), indicating heavier male-biased philopatry, where males are more likely to be the non-dispersing sex. Comparing results from a similar study we conducted on a rural population of BCTI in San Marcos in 2013 – 2015, BCTI nestling and adult body condition did not differ between urban and rural populations, nor did they differ between years or by fledge date. Though urban BCTI construct kin-structured neighborhoods similar to rural populations, the proportion of families that contained a limited dispersing juvenile was lower in urban areas compared to the rural site (51% compared to 68%, respectively). These variations may be explained by differences in available habitat (including suitable nesting cavities), food accessibility, and the presence of non-native predatory threats.

Talking Trash in the Big Apple: Mitigating Bird Strikes Near the North Shore Marine Transfer Station
Stephan Beffre, Brian Washburn

Anthropogenic activities that concentrate wildlife near airports increased the risks of wildlife-aircraft collisions. Placing waste management facilities, natural areas, golf courses, and other landscape features near airports have the potential to attract wildlife hazardous to aviation. We conducted a 3–year study (March 2013-February 2016) to determine if the implementation of a Wildlife Hazard Mitigation Program (WHMP) would influence the bird use of a waste transfer station located near the New York City, USA, LaGuardia Airport. We conducted wildlife surveys during 3 Phases: 1) no mitigation program and no waste transfer station, 2) active mitigation and no waste transfer station, and 3) active mitigation and operating waste transfer station. Overall, bird abundance decreased when the WHMP was implemented, thereby reducing the risk of wildlife strikes with aircraft operating in association with LaGuardia Airport. The active mitigation program reduced the presence of birds associated with the waste transfer station as well as many species using the adjacent marine environment.

How Does Urbanization Impact the Distribution of a Habitat Specialist in An Urban Forest Fragment
thomas stevens, Amanda Hale, Dean Williams

Urbanization endangers more species in the United States than any other human activity as it dramatically modifies natural landscapes, fragments previously intact habitats, and is spreading rapidly. Species with specialized habitat requirements are more severely impacted by urbanization than other species, and are usually absent from habitat fragments surrounded by an urban matrix. We studied the impacts of urbanization on the distribution of the swamp rabbit (Sylvilagus aquaticus) in the Great Trinity Forest, one of the largest urban forests in the United States located in Dallas, TX. Swamp rabbits are habitat specialists and are considered indicator species for healthy bottomland hardwood forest in the southeastern United States. We located 647 swamp rabbit latrines in the Great Trinity Forest between December 2018 and May 2021 as part of a broader study examining the conservation genetics of swamp rabbits in the forest. We analyzed the impacts of both urbanization (noise pollution, light pollution, invasive species, and matrix urbanization) and naturally occurring habitat heterogeneity (forest structure and composition) on the distribution of swamp rabbit latrines in the Great Trinity Forest using the presence only modelling framework Maxent. Our study provides important insights into which factors most influence the distribution of habitat specialists in an urban forest and therefore how they can be conserved in other urban forest fragments. 

Herring Gull Conservation and Management on An Urban Green Roof
Dustin Partridge, Kaitlyn Parkins

The Jacob K. Javits Convention Center green roof is a 7,316m2 Sedum sp. green roof in midtown Manhattan in New York City. Installation was completed in early 2014 and in the Spring of 2014 eight pairs of Herring Gulls (Larus argentatus) nested on the green roof. The Herring Gull colony grew each year, reaching at least 161 nests in 2020. While the initial colony of Herring Gulls was welcomed by building management, the increase in the number of gulls has resulted in destruction of the green roof, windows, and essential equipment on the roof. Thus, in 2021, we began a novel gull conservation and abatement program to reduce the number of nesting pairs and encourage nesting in a gull Conservation Zone established on the green roof. Using non-lethal methods we harassed gulls and destroyed eggless nests that were built outside of the Conservation Zone throughout the nesting season. Herring Gulls rapidly responded to our presence and began nesting in the Conservation Zone by early May. Overall, we reduced the total number of gulls nesting on the roof, and while some gulls did nest outside of the Conservation Zone, the highest density of gulls occurred within the Conservation Zone. We document a practical method for green roof gull control that is safe for gulls, maintains a portion of the green roof for gull conservation, allows continuous access to the roof for maintenance, and is relatively inexpensive when compared to other gull control methods such as wildlife control dogs and lasers. By using human harassment and providing a nesting Conservation Zone we were able to successfully manage a Herring Gull colony while maintaining the habitat value of a green roof.

Rethinking Mammal Habitat Occupancy Modeling and the Role of Diel Activity in An Anthropogenic World
Mason Fidino, Kimberly Rivera, Brian Gerber

Diel activity patterns—the distribution of activity over a 24-hour light-dark cycle—is fundamental to an animal’s ecological role and thus an integral component of niche theory. Yet, questions about species temporal and spatial habitat components are too often treated separately, especially within occupancy-based studies. By ignoring diel period, occupancy-based studies have focused on average daily conditions rather than those prevailing at the time of day when individuals of a species would tend to be most active. To address this issue, we developed a multi-state diel occupancy model (MSDOM) which incorporates diel activity information into an occupancy modeling framework and can therefore be used to investigate how human activity and urbanization may simultaneously influence both where and when a species may occur. Unlike other techniques, our MSDOM can include continuous covariates so that shifts in a species diel activity can be explored across space and through time. Because of this, species diel-activity patterns can be evaluated across urbanization gradients rather than “urban” or “rural” categories. As an example, we applied a dynamic MSDOM to coyote (Canis latrans) data from a large-scale long-term camera trapping survey throughout Chicago, Illinois, USA to determine if coyote were more nocturnal with increasing levels of urbanization. Overall, we found that daytime use of habitat patches by coyote were roughly three times greater at lower levels of urban intensity than high levels. Likewise, nighttime use of habitat patches was greatest at higher levels of urban intensity. With this method and the growing availability of spatio-temporal datasets, ecologists can better evaluate both where and when a species may use habitat in the Anthropocene.

Habituation or Sensitization? Long-Term Responses of Yellow-Bellied Marmots to Human Disturbance
Kenta Uchida, Daniel Blumstein

The increase in urban areas and the popularity of outdoor activities has resulted in wildlife increasingly exposed to humans. Continuous exposure to humans causes wildlife to either habituate or sensitize. Although increased tolerance may play important role in coexistence with humans in urban areas and outdoor recreational sites, the mechanisms and fitness outcomes of long-term changes of tolerance are not fully understood because only a few studies have assessed individual and population-level responses over many years. We developed a novel predictive framework to study habituation and sensitization to humans and applied it to yellow-bellied marmots (Marmota flaviventer) in areas of high and low human disturbance. We focused on two anti-predator behaviors–time allocation to vigilance during foraging to quantify baseline vigilance levels, and flight initiation distance (FID)–to quantify subsequent responsiveness to threat. We used the rate of body mass gain during the active season as a fitness outcome. Assessing 15 years’ population and individual level responses to human disturbances, marmots in highly disturbed colonies allocated more time to vigilance, but this did not change over time. FID decreased on average when they were approached more, and also tended to decrease in highly disturbed colonies and over 15 years. Yet, there was individuality in FIDs; marmots that fled at greater distances became sensitized with repeated approaches. Additionally, the marmots in highly disturbed colonies gained less body mass over time compared to conspecifics in less disturbed colonies. These results suggested that, although marmots habituated to humans, long-term human disturbance has negative fitness consequences. Our framework should help wildlife managers evaluate the comprehensive impact of human activities on wildlife.

Drivers of Nest Survival: Insights from a 30-Year Study of Black-Crowned Night-Herons on Alcatraz Island, San Francisco, California
Diana Munoz, Peter Coates, Brianne Brussee, Joshua Hull

Nest monitoring is a key component of many avian species monitoring and management programs. Annual variability in nest survival can occur as a direct result of exposure to varying climatic conditions, availability of food resources, exposure to predation pressure, and parental behavior. Alcatraz Island provides important nesting habitat for multiple avian species within the San Francisco Bay Estuary in California. The National Park Service (NPS) initiated multiple monitoring programs in 1990 to balance human use and access while managing habitat for the island’s breeding avifauna. In collaboration with the NPS, the U.S. Geological Survey has monitored black-crowned night-heron (Nycticorax nycticorax) nests on the island to assess reproductive success since 1990, culminating in one of the longest running nest monitoring programs within the estuary. This population of night-herons is non-migratory and can therefore act as resident indicators of estuarine health. Given that small, short-term datasets often limit the number of hypotheses investigated, our 30-year dataset provided a valuable opportunity to estimate the influence of environmental factors on night-heron nest survival. We assessed multiple a priori hypotheses using Bayesian logistic exposure models to examine nest survival in response to covariates related to nest placement, nest timing, predation, weather, and productivity. We found that nest survival was positively influenced by timing, temperature, precipitation, and productivity. Specifically, models indicated that warm and rainy conditions were favorable for nesting. Additionally, an increase of 1,000 anchovies, based on monthly catch data within the Bay, resulted in a 5.5% increase in nest survival. Our findings addressed demographic trends in a top estuarine predator and can be used to guide decisions that support sustainable nesting colonies within multiple-use urban settings. Findings are preliminary and provided for timely best science.  

Wealth and Urbanization Shape Mammalian Communities Across North America
Seth Magle, Mason Fidino, Heather Sander, Adam T. Rohnke, Kelli Larson, Travis Gallo, Cria Kay, Elizabeth Lehrer, Maureen Murray, Solny Adalsteinsson, Adam Ahlers, Whitney Anthonysamy, Ashley Gramza, Austin Green, Mark Jordan, Jesse Lewis, Robert Long, Br

Urban biodiversity provides critical ecosystem services and is a key component to environmentally and socially sustainable cities. However, biodiversity varies greatly within and among cities, leading to human communities with changing and unequal experiences with nature. The “luxury effect”, a hypothesis that predicts a positive correlation between wealth, typically measured by per capita income, and species richness may be one indication of these inequities. While the luxury effect is well studied for some taxa, it has rarely been investigated for mammals, which provide unique ecosystem services and exhibit significant potential for negative human-wildlife interactions (e.g. nuisances or conflicts). We analyzed a large dataset of mammal detections across 20 cities to test whether the luxury effect is consistent for medium- to large-sized terrestrial mammals across diverse urban contexts. Overall, support for the luxury effect, as indicated by per capita income, was inconsistent; we found evidence of a luxury effect in approximately half of our study cities. Species richness was, however, highly and negatively correlated with urban intensity in most cities. We thus suggest that economic factors play an important role in shaping urban mammal communities for some cities and species, but that the strongest driver of urban mammal diversity is urban intensity. To better understand the complexity of urban ecosystems, ecologists and social scientists must consider the social and political factors that drive inequitable human experiences with nature in cities.

Emerging Themes in Natural Resource Management: Highlights from the 2021 Urban Wildlife Conference
Richard Heilbrun

Wildlife Management is people management, plain and simply.   Regardless of what aspect of natural resource management one finds themselves, our impact as professionals can be gauged by how well we can change behavior, influence policy, educate others, or spread the value of our research.  In 2021, the TWS Urban Wildlife Working Group conducted their biennial International Urban Wildlife Management Conference.  This year’s Conference focused on three emerging themes:  Diversity, Equity, and Inclusion, Working with local partners and municipalities, and Engaging audiences in a virtual world.  We cannot change the knowledge, perceptions, attitudes or behavior of our audiences without first acknowledging that our audiences may not represent our communities and constituents. Fortunately, urban wildlife professionals have been wrestling with this issue since before DEI became a trending topic. After broadening our audiences, natural resource professionals in urban environments have learned to work with local partners and local governments and to adapt messages and delivery methods accordingly, even in a virtual environment. This presentation will highlight components of the conference addressing these themes, and will provide insight to urban wildlife professionals on how others in the field are attempting to solve these challenges.  

Contributed Oral
Location: Virtual Date: November 3, 2021 Time: 4:00 pm - 5:00 pm