Decoding owl calls: Refining occupancy inference from passive acoustic monitoring

Decoding owl calls: Refining occupancy inference from passive acoustic monitoring | Authorea try { document.documentElement.classList.add('js'); } catch (e) { } var _gaq = _gaq || []; _gaq.push(['_setAccount', 'G-8VDV14Y67G']); _gaq.push(['_trackPageview']); (function() { var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); })(); Skip to main content Preprints Collections Wiley Open Research IET Open Research Ecological Society of Japan All Collections About About Authorea FAQs Contact Us Quick Search anywhere Search for preprint articles, keywords, etc. Search Search ADVANCED SEARCH SCROLL Ecology and Evolution This is a preprint and has not been peer reviewed. Data may be preliminary. 29 May 2025 V1 Latest version Share on Decoding owl calls: Refining occupancy inference from passive acoustic monitoring Authors : Natalie Rugg 0009-0007-3259-2177 [email protected] , Cara Appel 0000-0002-4761-606X , Julianna Jenkins 0000-0002-6290-0018 , Chris McCafferty , Taal Levi 0000-0003-1853-8311 , and Damon Lesmeister 0000-0003-1102-0122 Authors Info & Affiliations https://doi.org/10.22541/au.174854177.79188832/v1 Published Ecology and Evolution Version of record Peer review timeline 415 views 327 downloads Contents Abstract Supplementary Material Information & Authors Metrics & Citations View Options References Figures Tables Media Share Abstract 1) Effective conservation of the northern spotted owl (Strix occidentalis caurina) requires accurate occupancy and space use information, especially as passive acoustic monitoring becomes the primary population assessment method. Spotted owls actively vocalize in core use areas during the breeding season, but interpreting acoustic data is complicated by variable detectability—particularly for females—and interference from invasive barred owls (S. varia). 2) Using a dense network of autonomous recording units deployed 0–3 km from known activity centers, we quantified spotted owl vocal activity by sex and context. We additionally analyzed detection patterns from regional monitoring sites overlapping our study area to refine our understanding of detectability. 3) Male four-note calls were detected more frequently and consistently than female calls, and detection rates decreased with barred owl presence. Female calls were infrequent and restricted to the activity center and immediately adjacent areas, especially if nesting. 4) Vocal space use areas were similar in size but smaller than published home ranges, reinforcing that territorial calls represent high-use areas, not full spatial use. Synthesis and applications 5) We propose a detection-based spectrum of weeks with detection for inferring site occupancy that accounts for calling rate, caller sex, and project objectives. Stricter thresholds can minimize false positives in population assessments, while inclusive thresholds reduce false negatives in habitat protection. Our results support nuanced, objective-based thresholds for interpreting spotted owl detections from passive acoustic monitoring. This approach balances accuracy with conservation risk tolerance, demonstrating that suitable habitat extends beyond acoustically inferred territories. By clarifying vocal behavior, this study advances the application of passive acoustic monitoring for habitat management and occupancy estimation amid invasive species pressures and ongoing landscape change. Supplementary Material File (decoding owl calls - full manuscript with appendix.docx) Download 13.49 MB Information & Authors Information Version history V1 Version 1 29 May 2025 Peer review timeline Published Ecology and Evolution Version of Record 9 Oct 2025 Published Copyright This work is licensed under a Non Exclusive No Reuse License. Collection Ecology and Evolution Keywords behavioral ecology comparative natural history statistical terrestrial vertebrate Authors Affiliations Natalie Rugg 0009-0007-3259-2177 [email protected] US Department of Agriculture Forest Service View all articles by this author Cara Appel 0000-0002-4761-606X US Department of Agriculture Forest Service View all articles by this author Julianna Jenkins 0000-0002-6290-0018 US Department of Agriculture Forest Service View all articles by this author Chris McCafferty US Department of Agriculture Forest Service View all articles by this author Taal Levi 0000-0003-1853-8311 Oregon State University View all articles by this author Damon Lesmeister 0000-0003-1102-0122 US Department of Agriculture Forest Service View all articles by this author Metrics & Citations Metrics Article Usage 415 views 327 downloads .FvxKWukQNSOunydq8rnd { width: 100px; } Citations Download citation Natalie Rugg, Cara Appel, Julianna Jenkins, et al. Decoding owl calls: Refining occupancy inference from passive acoustic monitoring. Authorea . 29 May 2025. DOI: https://doi.org/10.22541/au.174854177.79188832/v1 If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download. For more information or tips please see 'Downloading to a citation manager' in the Help menu . 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