Assessment of Avian Community Structure and Habitat Connectivity in the Fanno Creek Corridor Bird Surveys, Habitat Assessment, and Management Recommendations

Author

Grace Hall, Portland State UniversityFollow

Community Partner

Clean Water Services and the Bird Alliance of Oregon

First Advisor

Catherine de Rivera

Date of Award

2024

Document Type

Project

Degree Name

Master of Environmental Management (MEM)

Department

Environmental Science and Management

Language

English

Abstract

Urbanization can significantly impact habitat quality and connectivity for avian communities, decreasing species richness and diversity (Marzluff 2001; Dri et al. 2021). However, in highly fragmented habitats, urban parks and riparian zones can provide important habitat corridors for birds that facilitate movement and access to essential resources (Şekercioğlu et al. 2015; Keten et al. 2020). On the west side of greater Portland, Oregon, Fanno Creek may serve as a habitat corridor for birds and other local wildlife.

Fanno Creek is a 25-kilometer tributary of the Tualatin River that runs through the cities of Portland, Beaverton, Tigard, and Durham in northwestern Oregon. The land surrounding the creek includes residential, commercial, and industrial properties as well as multiple public parks connected by a greenway trail. Local agencies such as Clean Water Services, Environmental Services, and Portland Parks and Recreation have completed numerous restoration projects along Fanno Creek to improve habitat function. Examples of these management efforts include native revegetation, erosion control, re-meandering of the steam channel, removal/replacement of infrastructure harmful to wildlife, floodplain restoration, and development of rain gardens to treat stormwater before it enters the creek.

The presence of connected parks and other green spaces along Fanno Creek provides potential opportunities for wildlife movement through the highly urbanized surrounding environment as well as opportunities for stopover during long distance migrations. Clean Water Services, one of the community partners for this project, is interested in an evaluation of how restoration efforts have increased habitat quality and connectivity along Fanno Creek.

The goal of this study was to examine if Fanno Creek is functioning as an effective habitat corridor for three bird species representative of different habitat needs. Methods were twofold: a habitat permeability assessment and point count surveys. Habitat permeability scores for each species were assigned across the study area following the methods described in the Metro Wildlife Habitat Connectivity Assessment Toolkit (hereafter identified as “the Toolkit”)(Bliss-Ketchum et al. 2018). Point counts followed protocol standard for avian surveys in the Pacific Northwest (Huff et al. 2000), adjusted to accommodate the spatial dimensions and temporal constraints of the project. A secondary goal of the project was to test the effectiveness of the Toolkit’s habitat assessment tools for assessing habitat use by birds. The research questions that this project addresses include the following:

❖ Do the habitat permeability scores generated by the Metro Wildlife Habitat Connectivity Assessment Toolkit correspond with abundance of surrogate bird species along Fanno Creek?

❖ What is the migratory/early breeding avian community structure along the southern reach of Fanno Creek?

❖ What do areas with lower Toolkit scores/species richness have in common in regard to habitat, and how might these habitat segments be improved for local wildlife?

These research questions provide insight into A) the effectiveness of the Toolkit in estimating presence of surrogate species in a small-scale study, B) the current avian community structure along Fanno Creek, and C) sections of the creek that may be targeted for future management efforts according to Toolkit habitat permeability scores and species abundance and richness.

Rights

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Comments

A project report submitted in partial fulfillment of the requirements for the degree of Master of Environmental Management.

See below for supplemental files, Appendices A-F

Persistent Identifier

https://archives.pdx.edu/ds/psu/42478

Recommended Citation

Hall, Grace, "Assessment of Avian Community Structure and Habitat Connectivity in the Fanno Creek Corridor Bird Surveys, Habitat Assessment, and Management Recommendations" (2024). Environmental Science and Management Professional Master's Project Reports. 84.
https://pdxscholar.library.pdx.edu/mem_gradprojects/84