Carnivore Ecology in the Built Environment

Symposium
ROOM: CC, Room 21
SESSION NUMBER: 68
 
The majority of our understanding of carnivore ecology has come from studies conducted in predominately undeveloped areas located far from humans and generally undisturbed by urbanization. Yet, in the last several decades it has become clear that carnivores can persist and even thrive in the built environment associated with urban, suburban, and exurban landscapes. The presence of carnivores in the built environment creates numerous challenges for science and society, including how to mitigate human-carnivore conflict, how to manage urban park systems in ways that support (or limit) carnivore populations, and how to evaluate predictions stemming from existing ecological theory in urban contexts. This symposium outlines current knowledge regarding carnivores and the built environment and addresses key, outstanding gaps in current understanding that hinder both the development of ecological theory regarding urban carnivores and the practical application of such theory for management and conservation. Topics of particular focus include 1) the community ecology of mammalian carnivore guilds in the built environment, 2) understanding the behavioral plasticity of carnivores in response to human activity and urban landscape structure, and 3) considering the crucial implications of habitat connectivity within and among cities for carnivore ecology. Overall, this symposium intends to catalyze the development of ecological theory and the creation of progressive management and conservation practice concerning carnivores and the built environment.

12:50PM Humans and the Built Environment Mediate the Sympatry of Competing Carnivores
  Remington J. Moll; Jonathon D. Cepek; Patrick D. Lorch; Patricia M. Dennis; Terry Robison; Joshua J. Millspaugh; Robert A. Montgomery
Humans can profoundly shape animal community dynamics, but such effects have rarely been evaluated for terrestrial carnivores. Humans affect carnivores in both spatial and temporal dimensions via the chance of human encounter and alteration of the landscape through urban development. We investigated three hypotheses regarding how humans mediate the sympatry of larger,dominant carnivores with their smaller, subordinate counterparts. We tested these hypotheses by examining the spatio-temporal dynamics of a dominant carnivore (coyote Canis latrans) and its subordinate competitor (red fox Vulpes vulpes) across an extensive urban park system. We found that dominant and subordinate carnivores exhibited strong and often opposing spatiotemporal responses to the probability of human encounter and urban development. Spatially, coyotes visited more highly developed sites less frequently while red foxes exhibited an opposing response. Temporally, both species avoided humans via nocturnal activity. Spatio-temporally, red foxes avoided coyotes at all sites and avoided humans at highly developed sites,whereas coyotes showed a positive association with humans at such sites. Our analysis indicates that areas with higher urban development might act as spatial refugia for some subordinate carnivores against interference from larger, dominant carnivores (a ‘human shield’ effect). Our findings also reveal that broad-scale spatial avoidance is likely a crucial component of coexistence between larger, dominant carnivores and humans, whereas finer-scale spatio-temporal avoidance is likely a key feature of coexistence between humans and smaller, subordinate carnivores. Overall, our study underscores the complex and pervasive nature of human influence over the sympatry of competing carnivores inhabiting urban systems.
1:10PM Co-Existence of Red Foxes and Coyotes in an Urban Landscape
  Marcus Mueller; David Drake; Maximilian Allen
Urban environments are increasing worldwide and are inherently different than their rural counterparts, with a variety of effects on wildlife due to human presence, increased habitat fragmentation, movement barriers, and access to anthropogenic food sources. Effective management of urban wildlife requires an understanding of how urbanization affects their behavior and ecology. The spatial activity and interactions of urban wildlife, however, have not been as rigorously researched as in rural areas. From January 2015 to December 2016, we captured, radio-collared, and tracked 11 coyotes and 12 red foxes in Madison, WI. Within our study area, coyotes strongly selected home ranges with high proportions of natural areas; conversely, red foxes selected home ranges with open space and moderately developed areas. Use of highly developed areas best explained variation among individual home range sizes and inversely affected home range size for coyotes and red foxes. Coyote and red fox home ranges showed some degree of spatial and temporal overlap, but generally appeared to be partitioned by habitat type within our study area. Coyotes and red foxes were both active at similar times of the day, but their movement patterns differed based on species-specific habitat use. This spatial partitioning may promote positive co-existence between these sympatric canids in urban areas, and our findings of spatial activity and interactions will better inform wildlife managers working in urban areas.
1:30PM Bold Temperament in Urban Coyotes: A Case of Humans as Indifferent Predators?
  Stewart W. Breck; Sharon Poessel; Peter Mahoney; Julie K. Young
Landscapes altered by people can influence animal behavior in a variety of ways including temperament. Here we compared boldness, a temperament trait, of coyotes (Canis latrans) in rural (central Utah) and urban (Denver, Colorado) systems, to determine how coyote temperament differs between these two landscapes. Important for this work is that in the rural area, coyotes were regularly trapped and shot by private and government trappers and in the urban system coyotes received little purposeful persecution by humans. We used two methods (flight initiation distance [FID] and novel object test) and recorded 5 behavioral measurements to study coyote temperament. One behavioral measurement from the FID test was equivocal and the other definitive in support of bolder urban coyotes. All three behavioral measurements from the novel object test supported the premise that urban coyotes are bolder in that they are willing to take more risk than rural coyotes. Overall, our results showed that urban coyotes exhibited bolder behavior than rural coyotes, which likely has contributed to more aggressive encounters between coyotes and people in urban environments. We attribute the difference in temperament to reduced human predation in the urban system and elaborate on how the study of carnivore temperament is important as societies focus on coexisting with carnivores rather than eliminating them.
1:50PM Resource Use and Density of Bobcats in an Extremely Urbanized Area
  Julie K. Young; Julie Golla; Derek Broman; Terry Blankenship; Richard Heilbrun
ABSTRACT Wildlife and people increasingly overlap in their use of space and resources due to rapidly expanding cities and a burgeoning global human population. Today, mammalian carnivores commonly occupy urban areas. Bobcats (Lynx rufus) are a top mammalian carnivore in several urban areas across the United States, yet there is a lack of data to guide urban wildlife management because most studies observe bobcats at the urban-wildland interface. We evaluated habitat utilization and population density of bobcats in a highly urbanized area of the Dallas-Fort Worth (DFW), Texas metroplex. Bobcats in the DFW occur at a higher density (0.64 bobcats/km2, SE = 0.22) and with smaller home ranges for residents (4.60 km2, SE=0.99 km2) than most rural and peri-urban bobcats. Bobcats selected areas closer to developed open space, agricultural areas, and railroads, suggesting urban bobcats seek out habitat that facilitate movement and foraging. Bobcats did not select for or against more natural features such as creeks, grass, and low-development areas. These results provide information to facilitate management of urban bobcats by providing new insight into how bobcats live amidst people in a highly developed ecosystem.
2:10PM Wild Suburbia: Mammal Communities Are Larger and More Diverse in Moderately Developed Areas
  Arielle W. Parsons; Tavis Forrester; Megan C. Baker-Whatton; William J. McShea; Christopher T. Rota; Stephanie G. Schuttler; Joshua J. Millspaugh; Roland W. Kays
Disturbance is thought to truncate food webs and reduce species abundance and diversity, leading to the paradigm that developed areas have low species diversity, low animal abundance, few native predators, and thus low resilience and ecological function. However, abundance and diversity can also be mediated by food availability, and for animals living in urban areas, food resources and disturbance could become decoupled if species can adapt to exploit human surpluses and altered habitat. Working with citizen scientists to survey mammals at 1427 sites across two urban development gradients (wild-rural-exurban-suburban-urban) and four plot types (large forests, small forest fragments, open areas and residential yards) in the eastern US, we show that developed areas had the highest occupancy, relative abundance, richness, and diversity of wildlife, including native predators. Most (92%) of the 13 mammal species detected >20 times occupied all levels of development above the urban level, suggesting substantial adaptation to human disturbance. Occupancy probabilities for carnivores in these developed landscapes were similar to those reported in protected areas around the world, and their variation was better explained by local measures of green space than by degrees of urbanization. Our results suggest that suburban and exurban areas can maintain mammalian species diversity and abundance at similar, if not higher levels, than wild areas. We hypothesize that these results are due to the ability of mammals to adapt to chronic human disturbance and take advantage of urban food resources while also having protection from over-exploitation. Although some animals can thrive in suburbia, conservation of wild areas and preservation of green space within cities are needed to protect sensitive species and to give all species the chance to adapt and persist in the Anthropocene.
2:30PM Refreshment Break
3:20PM Effects of Urbanization and Anthropogenic Subsidies on Cougar (Puma Concolor) and Black Bear (Ursus Americanus) Space-Use and Interactions along Western Washington’s Wildland-Urban Gradient
  Clint Robins
Habitat loss, overexploitation, urbanization, and other stressors have caused global declines in large mammalian carnivores. This “trophic downgrading” has led to widespread concern within the scientific community because apex predators can play a fundamental role in biodiversity maintenance, disease regulation, trophic facilitation, and overall ecosystem function by exerting direct and indirect effects. Whereas large carnivores tend to be especially vulnerable to urban development, recent research has documented multiple large carnivore species persisting in human-dominated landscapes across Europe and the United States. Most urban carnivore studies, however, have chosen to focus on intraspecific interactions. Relatively few studies, by contrast, have investigated how urbanization influences interspecific interactions within carnivore guilds. Accordingly, we investigated competitive interactions between black bears (Ursus americanus) and cougars (Puma concolor) along a wildland-urban gradient in western Washington, USA. We hypothesized that, along this gradient, the proximity of anthropogenic food resources for bears to cougar kill sites would increase the likelihood of a cougar kill being scavenged by a bear, and that cougars experiencing strong competition with bears would respond by hunting small-bodied prey. Results from this study may improve our understanding of how changes in cougar and black bear interactions across anthropogenically-modified landscapes can shape ecological communities. Moreover, previous research has indicated that black bears limit carrion acquisition by subordinate scavengers more so than cougars, suggesting that competition between black bears and cougars may have effects on the scavenger community.
3:40PM Native and Domestic Carnivore Use of the Wildland-Urban Interface
  Ashley Gramza; Tara L. Teel; Sue VandeWoude; Kevin R. Crooks
Free-ranging domestic cats, including feral animals or pets allowed outside, impose risks on the natural ecosystems they visit. For example, cats may exert predation pressure on local prey populations, transmit disease to wildlife, or compete with mesopredators. Conversely, cats can incur risks from wildlife including harassment and predation by native carnivores and increased exposure to disease. These various risks that free-ranging cats both incur and impose are likely compounded near the urban-wildland interface (WUI), however little is known about domestic cats and their potential interactions with wildlife (both prey species and carnivores) near these areas. To enhance our understanding of the temporal and spatial use of domestic cats and other wildlife along the WUI, we placed 25 cameras along the wildland-urban interface west of Boulder, Colorado. These un-baited cameras ran for 12 continuous months from October 2011-Oct 2012 and were located along 5 transects and at 5 distance intervals (0, 100, 250, 500, and 1000 m) away from the WUI. During this time period, we captured 254 images of domestic cats and 152,623 images of wildlife. Domestic cat photos decreased with distance from the WUI. Conversely, many wildlife photos were captured near the WUI showing evidence of spatial overlap between domestic cats and wildlife. Furthermore, we also captured photos of domestic cats preying on wildlife and of carnivores interacting with and preying upon domestic cats. Results of this research can be used to target management strategies and public education programs aimed at reducing risks associated with free-ranging domestic cats.
4:00PM Moving Through the Matrix: Promoting Permeability for Pumas in a Human-Dominated Landscape
  Justine A. Smith; Timothy P. Duane; Christopher C. Wilmers
Landscape connectivity for wildlife populations is declining globally due to increasing development and habitat fragmentation. However, outside of full protection of undeveloped wildlife corridors, conservation planners have limited tools to identify the appropriate level of densification such that landscape permeability for wildlife is maintained. Here we use the movement paths from 28 male pumas in Santa Cruz County to identify threshold levels of development that produce barriers to movement. We then apply this threshold to projected housing densities of existing parcels under a full General Plan buildout scenario to illustrate how to identify parcels at risk of increasing above the puma movement threshold. We demonstrate how these parcels can be further prioritized for conservation using a conservation rank derived from parcel size, size of adjacent parcels, current housing density, and projected housing density. The ranking approach we describe predicts landscape permeability value for pumas well, as the number of puma movement paths that intersect a parcel were significantly correlated with its conservation rank. We discuss how our findings and approach can be used by conservation planners to promote landscape permeability for wide-ranging wildlife in already partially developed landscapes.
4:20PM The Connectivity Potential of Chicago’s Green Infrastructure Vision in the Face of Urban Population Growth
  Travis Gallo; Mason Fidino; Liza Lehrer; Seth Magle
In 2004, the Chicago Wilderness Alliance proposed a Green Infrastructure Vision (GIV), outlining strategies for protecting and restoring ~1.85 million acres of urban green space in the greater Chicago region. Landscape connectivity was a central component of the GIV planning processes. However, few have assessed the GIV’s potential to contribute to landscape connectivity using empirical data. Using data from the long-term Chicago Biodiversity Monitoring Project, we assessed how well the GIV contributes to landscape connectivity for urban carnivores at varying levels of implementation. We also assessed how well the GIV might contribute to connectivity under future (2040) predictions of human population densities. While, landscape connectivity analyses (e.g., least-cost paths, circuit theory) are informative about the landscape structure between green spaces (urban matrix), they fail to account for metapopulation dynamics (i.e. colonization and extinction) that occur between and within these green spaces (habitat patches). We used a recently published model by Howell et al. (2018) to unify both landscape connectivity and metapopulation dynamics to assess a more biologically relevant contribution of the GIV to urban wildlife conservation. We will present our results from estimating spatially explicit colonization rates between urban green spaces and the contribution urban green spaces offer to carnivore connectivity across the greater Chicago region. We will also present how proposed green spaces will contribute to local persistence rates of urban carnivores.
4:40PM Advancing Urban Carnivore Research Through a Multi-City Collaboration
  Seth Magle; Mason Fidino; Elizabeth W. Lehrer; Travis Gallo; Matthew P. Mulligan; Maria J. Rios; Adam A. Ahlers; Julia Angstmann; Amy Belaire; Barbara Dugelby; Ashley Gramza; Laurel Hartley; Brandon MacDougall; Travis Ryan; Carmen Salsbury; Heather Sander
Urban wildlife research has the capacity to guide future interactions and co-existence between humans and wildlife in developed regions. Yet most urban wildlife research is limited to short-term, single-species studies typically conducted within a single city. This restricted focus prevents us from deriving global patterns and first principles regarding urban wildlife behavior and ecology. To overcome these limitations, we have designed a pioneering research network, the Urban Wildlife Information Network, where partners collaborate across multiple cities to collect long-term, systematic, multi-species data. Data collected via this network support analyses that will enable us to build basic theory related to urban wildlife ecology. An analysis of mammals in seven metropolitan regions suggests that common species are similar across cities, but rare species are remarkably different. Further, the spatial distribution of species within a city varies greatly. Our network has the potential to advance knowledge and improve our ability to plan and manage cities to support biodiversity.

 
Organizers: Robert Montgomery, Michigan State University, East Lansing, MI; Remington Moll, Michigan State University, East Lansing, MI; Seth Magle, Lincoln Park Zoo, Chicago, IL
 

Symposium
Location: Cleveland CC Date: October 10, 2018 Time: 12:50 pm - 5:00 pm