Collaborative Research: Linking social-environmental health to the trophic and disease dynamics of urban carnivores

University Of Washington, Seattle WA

Investigators

Abstract

Urban areas are expanding worldwide, presenting a major challenge to biodiversity conservation because many species are unable to persist in these human-dominated landscapes. However, some species do persist and even thrive in cities, including carnivores that play critical roles in ecosystems. Despite the ecological and societal importance of urban carnivores, key knowledge gaps remain in understanding how and why their populations change within and across cities. In this project, the researchers hypothesize that the same environmental health disparities that affect people in cities likewise affect carnivore populations through the joint effects of toxicants, altered diets, and disease risk. A better understanding of the health and disease dynamics of urban carnivores could help to prevent future disease outbreaks, because carnivores are important hosts for many diseases that infect humans. Additionally, urban carnivores may serve as early warning sentinels of environmental problems in cities because toxicants and infectious agents can build up in their bodies due to their high position in the food web. This study will provide insights that will allow urban planners to better predict how measures taken to address societal inequities will affect urban ecosystems via carnivores. For example, the project’s findings will reveal how actions such as pollution reduction or increasing green space should affect the abundance and health of urban carnivores. A better understanding of factors driving carnivore population dynamics in cities will promote biodiversity conservation in a rapidly urbanizing world. The researchers propose that urban carnivore population dynamics are principally governed by heterogeneity in environmental health via impacts on diet, disease prevalence, and toxicant exposure. Urban landscapes offer anthropogenic subsidies that fundamentally alter the risk, reward, and health consequences of foraging behavior compared to wildland areas. These novel connections among diet, toxicants, and infectious disease may strongly affect the population dynamics of urban carnivores in ways that are not possible to predict when each force is examined separately. The researchers will use health disparity maps along with wildlife camera trapping, necropsies of carnivore carcasses, stable isotope analysis, and genetic analyses of scats across three major metropolitan areas in the western US (Seattle–Tacoma, San Francisco Bay Area, and Los Angeles) to quantify these linkages. Because diet can strongly affect exposure to toxicants in urban areas, these factors are difficult to disentangle in studies of wild carnivores. The research team will therefore experimentally quantify the effect of diet on immune functioning by using diet trials with captive coyotes. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.