Global perspectives on urban wildlife conservation and management (hosted by TWS)

Rapid global urbanization impacts wildlife in a myriad of ways. Development and sprawl of built environments is drastically altering landscapes and landscape connectivity for wildlife and increased urbanization also affects how humans perceive and interact with the natural world. Urban landscapes themselves act as extreme filters for selection in wild animals such that some species or phenotypes are successful in urban environments at the expense of others.  We present a symposium that outlines current research themes, challenges, and new approaches in the study of urban wildlife ecology, conservation, and management with a diverse and global perspective.

1:10PM Emerging Themes in Urban Wildlife Ecology: Updates from the 2019 International Urban Wildlife Conference
  Christopher Schell
This year the Urban Wildlife Working Group hosted their biennial International Urban Wildlife Conference in Portland, Oregon. Urban wildlife research has grown at an exceptional rate in the last decade, greatly informing and reshaping the way we understand wildlife populations and behaviors in human-dominated ecosystems. These developments, however, do not exist nor should they be perceived to occur in a people/community-less vacuum. As urban wildlife professionals, we are uniquely positioned to engage urban communities and invite them to participate in scientific research. Thus, the theme of this year’s conference was Collaboration & Conservation: Applications to Urban Wildlife. The main objective of this year’s conference was to bring together wildlife professionals that have diverse study organisms, but unified by a single thread: community engagement as an extension of their research programs. In this presentation we will give an update from the 2019 International Urban Wildlife Conference. We will focus on stories that materialized from the main conference theme, and touch on additional emerging topics in urban wildlife research.
1:30PM What Does Urbanization Mean? a Framework for Urban Metrics in Wildlife Research
  Remington Moll
Extensive research has demonstrated that urbanization strongly alters ecological processes, often perniciously. However, quantifying the magnitude of urban effects and determining their generalizability depends on the ways urbanization is measured and modeled. We coupled a formal literature survey with a novel conceptual framework to document and synthesize the myriad of metrics used to quantify urbanization. The framework catalogs urban metrics by identifying i) the urban component measured, ii) the method of measurement, iii) the metric’s spatial scale, and iv) the metric’s temporal nature. Thus, the framework captures the what, how, where, and when of urban metrics. Our survey of 244 recent studies documented striking variability in urban metrics with respect to which urban components were measured as well as how, where, and when they were quantified. Overall, our survey revealed that metrics tended to be: i) be structurally-focused, ii) methodologically simplistic, iii) spatially variable, and iv) temporally static. The variation in urban metrics complicates the development of theory, comparisons of findings across studies, and the implementation of management and conservation actions. To pave a clear path forward for more efficient and policy-relevant urban research, we highlight several crucial areas for future research, including: i) systematic assessments of urban metrics across multiple scales, ii) an increased and judicious use of more complex urban metrics aimed at evaluating both mechanistic and broad-scale correlative ecological hypotheses, and iii) an increased emphasis on the socio-economic aspects of urban effects.
1:50PM Ecology of Suburban Mesocarnivores – Red Fox and Domestic Cats
  Irene Castañeda González
In urbanized areas, some species (synurbic species) may take advantage of the access to new resources and habitat types. In these human altered habitats, the decreased of large predators, leads to the increase of wild medium-sized predators. In addition, the presence of domestic predators, commensal prey species and anthropogenic refuses modify trophic interactions in urbanized areas. Domestic cats (Felis silvestris catus) and red foxes (Vulpes vulpes) are among the most abundant medium-sized carnivores in European urbanized areas. Although their diets were described in these areas, neither their concomitant predation pattern nor their prey selectivity were studied yet. Here, we monitored prey availability (in abundance, diversity and richness) and domestic cat and red fox diets in three suburban habitats (park, agricultural land and forest) during two years field work to evaluate the prey selectivity by both predators. We detected significant differences in prey richness and diversity inter- and intra-habitats. In addition, lagomorph, small mammal, bird and invertebrate densities were significantly affected by habitats and seasons. The overall domestic cat diet richness was lower than red fox diet richness, while domestic cat diet diversity was higher than red fox diet diversity. We assess significant differences in domestic cat and red fox diet richness and diversity according to habitats and seasons. Overall both predators positively selected vertebrate prey (mammals and birds). Thus, domestic cats and red foxes may have a synergetic effect on those prey populations. For this reason, we strongly recommend that future studies simultaneously monitoring prey availability and predator diets to assess concomitant predator impacts, particularly in urbanized areas.
2:10PM Invasive Species in Urban and Suburban Areas: The Eradication of Alien Squirrels in Italy
  Maria Vittoria Mazzamuto
In recent decades the rate of new introductions and the number of invasive alien species (IAS) in Europe have increased, raising extinction risks for many taxa and affecting human health and economy. When measures to prevent the introduction of IAS fail, eradication and management of established IAS are the most concrete and economically advantageous responses to biological invasions. The LIFE09-NAT/IT/095 project was realized with the contribution of the LIFE financial instrument of the EC and was carried out in Northern Italy to protect the Eurasian red squirrel (Sciurus vulgaris) in urban and suburban areas through the removal and control of invasive alien squirrels: the Eastern grey squirrel (Sciurus carolinensis) and the Pallas’s squirrel (Callosciurus erythraeus). The project used an integrated approach that included removal of the invasive squirrel populations, habitat improvement for the red squirrel and communication strategies to inform and improve public opinion. Although the project achieved some encouraging results, the eradication of the invasive squirrels is far from complete. Local eradications of invasive squirrels in some sites resulted in natural recolonization by native red squirrels and guidelines for forest management favorable to the red squirrel were developed and applied in one region. However, the invasion was wide and scattered and funding was insufficient to cover necessary manpower costs. Moreover, many private land owners refused access to their estates, that became a refuge and source site for the IAS, and strong opposition against euthanasia of animals in public parks prevented the accomplishment of the removal actions. Therefore, in a urban park, flexible management resulted in the first case in Italy of almost 400 grey squirrels successfully neutered and translocated. New actions are now ongoing in order to ensure the effectiveness of the results already achieved and to improve the conservation tools and status of the native red squirrel.
2:50PM Refreshment Break
3:00PM Large Predator Conservation in Human-Dominated Landscapes of India
  Rekha Warrier
Large carnivore populations are now increasingly restricted to fragmented habitats within human dominated landscapes. On account of their wide-ranging behaviors they are increasingly found beyond the boundaries of protected habitats, amidst human populations. The long-term persistence of large carnivores now increasingly depends upon reimagining the conservation value of human modified lands and embracing land-sharing based conservation initiatives. This requires both an understanding of large carnivore space use within novel habitats and the socio-ecological conditions that foster human-large carnivore coexistence. This issue is of relevance to the conservation of tigers (Panthera tigris). Nearly 70 % of the species global population occurs within India, the second most populous nation in the world. Agricultural areas surrounding protected habitats in India not only offer movement routes to tigers but are also the venues where intense conflicts with the species plays out. I conducted a study in the Terai Landscape which harbors a globally significant metapopulation of tigers amidst extremely dense human populations. The region has experienced a spike in human-tiger conflicts in recent years. I examined how sugarcane farmlands in the area are used by tigers and their prey species. I found that sugarcane farmlands provide seasonal habitats to tigers and their prey. These farmlands experience high use in the winter season when cover provided by the sugarcane crop is at its maximum. While human-tiger conflicts occur with high frequency in the landscape, my results indicate that these conflicts occur over a significantly smaller subset of the landscape over which human and tigers spatially overlap. In addition, despite a spate of recent conflict events with tigers, local community members show favorable attitudes towards wildlife conservation. I discuss the implications of these results in furthering our understanding of the feasibility of land-sharing based conservation actions for large carnivores.
3:20PM Land Cover Trends in South Texas (1987-2050): Potential Implications for Ocelot Recovery and Wild Felid Populations
  Jason Lombardi
The Rio Grande Delta and surrounding rangelands (10,065 km2) of southern Texas has become one of the fastest urbanizing regions in the United States over the last 35 years Coupled with rapid urbanization, this region is noted for productive agriculture and rangeland, while retaining the distinction as a rich biodiverse region in Texas. Since the early twentieth century, conversion of woody cover for agriculture and human development has become one of the main drivers of the decline of endangered ocelots (Leopardus pardalis), and the extirpation of jaguars (Panthera onca) and jaguarundi (Puma yagouaroundi) in South Texas. We classified LANDSAT imagery from 1987 to 2016 to quantify different rates of land cover change and used housing density scenarios to project changes in the amount and spatial distribution of woody cover until 2050 and its potential impact of wild felid habitat. From 1987 to 2016, woody cover increased from 3.9% along with patch density and edge density, whereas mean patch area, and Euclidean nearest neighbor decreased. Closer inspection revealed that woody encroachment of small patches (<1 ha) was the leading cause of woody cover increase by a magnitude of 4, with an observed significant skewness and kurtosis in the frequency distribution of patch size across years. By 2050, urbanization will be the dominant landscape type (39.9%) and at least 200 km2 of woody cover may be lost. Urbanization will have the greatest impact on woody cover near the US-Mexico border, thereby affecting ocelot, bobcat (Lynx rufus) and mountain lion (Puma concolor) populations in South Texas over the next 32 years. By 2050, the largest patches of woody cover will be located on private lands >60 km north of the US-Mexico border. These results provide important information for predicting future woody cover fragmentation to focus efforts for connectivity of wild felid populations.
3:40PM Urban Bird Conservation, Education, and Citizen Science in Mexico
  David García Solórzano
Ciudad Juarez, Chihuahua, represents an example of an urban community with an environment and social fabric damaged, in general terms, by the so-called social violence. The use of public spaces such as parks and gardens in this city is limited by the acts of violence associated with these sites, which on the other hand constitute redoubts of ecological niches for birds and other wildlife. In a fragmented and fearful society of living in public spaces, the activities proposed and executed by the Urban Bird Program-Ciudad Juarez group, such as the organization and development of bird sightings and the provision of information regarding the biology of the species and their ecological role, in schools and public parks, have become a reference model of social welfare, even for the students of Veterinary Medicine of the Autonomous University of Ciudad Juarez, because it allowed them the integration of a working group constituted by women with the aim of learning concepts and complementary visions to their academic formation and interest to highlight the importance of the native avifauna and share it with their community; what promotes and allows positive social interactions. These strategies seem to contribute to counteract and reduce the risk factors of social violence, which is remarkable and attributable to the teamwork of young women who bring benefits to their community, in a city classified in the past by specialists as the most dangerous city in the world.
4:00PM Application to Acquisition: Researching Rodenticide Pathways in Urban Wildlife
  Niamh Quinn
Anticoagulant rodenticides have been detected in many species of urban wildlife; yet the origins of exposure, route of exposure through the food web, and effects of this exposure on urban wildlife are not well understood. In California, and in most of the US, most research has been focused simply on detection of anticoagulant residues in wildlife species, an approach that fails to address any of these research concerns. This failure has led to an inability to improve applications of rodenticides in order to limit exposure of wildlife. Our research in urban southern California has been focused on the question surrounding the pathways of rodenticide from point of application to point of acquisition, using the coyote (Canis latrans) as the top predator in this urban system. Research includes the monitoring of bait stations and carcasses in suburban backyards to determine what non-target wildlife may be accessing the rodenticides through primary and secondary means, and how these may play a role in the exposure of urban coyotes. Research into the diet of the urban coyote has provided insight into potential food sources that could be the source of exposure. We also have begun to trace rodenticide applications up the food chain to investigate how persistent rodenticides are in urban food webs. We will discuss current results of these research projects and the impacts that they may have on informing policy regarding rodent management and wildlife conservation.

Organizers: Liza Lehrer, Melissa Merrick
Supported by: TWS Urban Wildlife Working Group, TWS Wildlife Damage Working Group, TWS International Wildlife Management Working Group

Location: Reno-Sparks CC Date: October 2, 2019 Time: 1:10 pm - 5:00 pm