First Advisor

Martin Lafrenz

Term of Graduation

Winter 2020

Date of Publication

5-22-2020

Document Type

Thesis

Degree Name

Master of Science (M.S.) in Geography

Department

Geography

Language

English

Subjects

Wildlife conservation, Urban wildlife management, Wildlife management, Red-legged frog -- Habitat -- Oregon -- Portland -- Case studies

DOI

10.15760/etd.7305

Physical Description

1 online resource (viii, 124 pages)

Abstract

Effective habitat connectivity tools that use GIS data perform well in remote areas but may not be as dependable in urban environments. The goal was to study uses and limitations of a conservation management tool in development, the Metro Regional Habitat Connectivity Toolkit, which evaluates connectivity for and permeability of wildlife movement. Habitat quality scores are generated from GIS-derived and field collected data such as connectivity patch/matrix characteristics, water source, vegetation, other structural components, wildlife observations, and human disturbance at survey sites. I compared GIS and field generated habitat quality scores for the Northern Red-legged Frog (Rana aurora) in urbanizing Gresham East Buttes, Oregon. Using Spearman's ranked correlation, there was low positive correlation between GIS and field scores indicating the two scores assess different types of data. The magnitude of difference between these scores had no interdependence along a development gradient. Assessment of Northern Red-legged Frog locations in Forest Park, resulted in habitat quality scores which were sensitive to the presence or visibility of water sources and other structural components such as woody debris. These findings indicate the need for repeat field surveys, and the importance of field-collected data's unique contributions which ensure crucial wildlife dispersal is protected in rapidly changing environments. To give regional conservation managers confidence in applying connectivity tools in urbanizing environments, I compared a predictive Circuitscape connectivity model to additional field collected data such as habitat quality, and distance between aquatic-terrestrial habitats using aquatic egg mass surveys for Northern Red-legged Frog. Further genetic and demographic studies are recommended to fully discern the implications of these findings and to protect this Oregon state strategy species that utilizes at-risk aquatic and terrestrial connections during its annual migrations.

Rights

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/32876

Available for download on Saturday, May 22, 2021

Included in

Geography Commons

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