Date of Award

12-2025

Document Type

Thesis

Degree Name

Master of Science (MS)

Degree Statement

Master of Science in Wildlife Biology & Conservation

Department

Department of Biology & Wildlife

Granting Institution

University of Alaska Fairbanks

Committee Chair

Brinkman, Todd

Committee Member

Candler, Ellen

Committee Member

Prichard, Alex

Table of Contents

Chapter 1: General introduction.

Chapter 2: The soundscapes of Alaska's Arctic Coastal Plain: spatiotemporal patterns across developed and undeveloped regions

Chapter 3: Paired camera traps and acoustic monitoring reveals disparate acute noise sensitivity in caribou on the Arctic Coastal Plain of Alaska

Chapter 4: General conclusions.

Abstract

Passive acoustic monitoring is an effective tool for collecting baseline acoustic data in remote locations and for advancing our understanding of soundscapes, the sound that emanates from a landscape. Terrestrial Arctic soundscapes remain understudied. The Arctic Coastal Plain (ACP) of northern Alaska is an ecologically, culturally, and economically significant region, containing a mix of land-uses and management practices. This study leverages a spatially large (~8,000 km2), multi-year dataset of acoustic recordings and paired images collected across the ACP to investigate how natural and anthropogenic factors influence the soundscape (Chapter 2), and how acoustic metrics influence the behavior of caribou (Rangifer tarandus) (Chapter 3), an important subsistence species. Analysis of over 36,000 hours of audio revealed that mean sound pressure levels (SPL; e.g., loudness) were significantly higher within the Prudhoe Bay Oilfield Complex (PBOC; 32.3 dBA) than in Arctic National Wildlife Refuge (ANWR; 29.3 dBA), driven in part by greater anthropogenic noise (13.8% vs. 1.8% of recordings) and biological sounds (53.0% vs. 44.3% of recordings). Over 4,600 caribou photo sequences were paired with acoustic data to test the influence of sound variables on the occurrence of disturbed behaviors. When modeling acute responses of caribou to co-occurring sound we identified a positive association between SPL and disturbed behavior, with the effect amplified when elevated SPL coincided with anthropogenic noise. Caribou at PBOC were markedly less likely to exhibit disturbed behavior than at ANWR, suggesting regional variation in responsiveness that may be linked to more frequent and long-term exposure to human activity. This work represents the first spatially extensive, multi-year assessment of the ACP soundscape and is the first to use paired acoustic and camera data to assess caribou behavioral response to sound. Collectively, these results provide land managers with a better foundation to assess the acoustic impacts of development in the Arctic.

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