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Occupancy Of Stream-Associated Amphibians Within The Interstate 90 Snoqualmie Pass Corridor, Anne Gustafson

All Master's Theses

Detection of stream-associated amphibians in visual encounter surveys is challenging due to their cryptic nature; however, occupancy models were developed to deal with these detectability problems and provide estimates of occupancy that can also be related to site characteristics. Highway crossing risks and habitat isolation were mitigated for in recent construction of wildlife underpasses, where creeks cross Interstate 90 east of Snoqualmie Pass in Washington State. The effects of these restored underpasses on stream-associated amphibians were evaluated across 8 creeks, some with and some without restored underpasses, by comparing modeled occupancy of 3 amphibian species in stream habitat upstream, under, …