First Advisor

Catherine de Rivera

Term of Graduation

Summer 2025

Date of Publication

8-8-2025

Document Type

Thesis

Degree Name

Master of Science (M.S.) in Environmental Science and Management

Department

Environmental Science and Management

Language

English

Subjects

Anthropogenic Behaviors, Camera Trapping, Community Experience, Human-Wildlife Interactions, Participatory Science, Urban Ecology

Physical Description

1 online resource (xv, 143 pages)

Abstract

Urbanization reshapes ecological processes by fragmenting habitat and altering patterns of human-wildlife interaction, often reducing biodiversity. However, at the household scale, residential yards can either enhance or inhibit ecological connectivity - functioning as informal habitat stepping stones or barriers to wildlife. This thesis examines how residents' environmental attitudes, wildlife experiences, and socio-demographic characteristics influence yard-level behaviors and shape the presence of urban-adapted wildlife species, particularly coyotes and domestic cats, across the Portland, Oregon metropolitan region. A mixed-methods, social-ecological framework guided the analysis, integrating survey data from 244 households with wildlife detections from motion-triggered cameras (Urban Wildlife Information Network, UWIN), citizen science reports (Portland Urban Coyote Project, PUCP), and U.S. Census-based demographic data within 0.5- and 1-mile spatial buffers. Survey responses were used to construct indices of environmental values (Stewardship, Biocentric, and Utilitarian) and yard behaviors (wildlife-encouraging, discouraging, and neutral). Cronbach's Alpha confirmed high internal reliability of the composite measures, which were subsequently analyzed through multiple and stepwise regression models. Results showed that Stewardship values were the strongest predictors of wildlife-supportive yard features - including native vegetation, bird feeders, and unstructured elements like wood piles - while Utilitarian values were weakly associated with deterrent features such as fences and impervious surfaces. Biocentric attitudes also correlated with higher habitat complexity. Although some behavioral patterns were associated with the frequency of seeing or hearing coyotes and cats, lived experiences were consistently weaker predictors than environmental values.

Correlations and regression models also revealed that demographic context significantly shaped wildlife detection patterns. Neighborhoods with higher percentages of young adults and residents holding graduate degrees were more likely to report or detect coyotes and cats, while lower-income and older populations were associated with fewer detections. Notably, PUCP coyote reports showed strong positive correlations with educational attainment and the proportion of Black and Asian residents, while income levels exhibited a negative relationship with coyote sightings across both survey and citizen science data. These relationships were confirmed through negative binomial regression models, underscoring the explanatory power of demographic structure. To assess concordance among the different data sources, Pearson and Spearman correlations and Welch's t-tests were used to compare detection values across survey-reported sightings, UWIN detections, and PUCP reports. While all three methods confirmed coyote and cat presence, correlation coefficients were moderate at best, and significant differences in mean detections were found between methods. These discrepancies highlight the importance of triangulating data collection approaches when evaluating urban wildlife presence, as each method reflects different spatial biases and observational limitations.

Taken together, these findings demonstrate that individual yard management decisions are more strongly influenced by attitudinal orientations than by direct wildlife encounters, and that residential areas, through their varied social and physical characteristics, can act as extensions of broader ecological networks. This conclusion is supported by consistent associations between demographic variables, environmental features, and the presence of wildlife-encouraging or discouraging yard behaviors. GIS-linked analyses revealed that the spatial distribution of wildlife sightings was not random, but instead followed patterns shaped by both environmental context and neighborhood demographic composition. Without integrating behavioral, demographic, and ecological data, such cross-scale relationships would remain obscured. This thesis underscores the need for interdisciplinary approaches in urban ecology and provides actionable insights for city planners, wildlife managers, and conservation educators - for example, designing neighborhood specific education campaigns or targeting stewardship initiatives toward communities with lower access to green space or higher prevalence of outdoor cats. As urban development continues, private yards will play an increasingly critical role in supporting biodiversity and maintaining ecological connectivity across metropolitan landscapes.

Rights

© 2025 Clarissa Emma Cressotti

In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/ This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).

Persistent Identifier

https://archives.pdx.edu/ds/psu/44159

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