Estimating cetacean population trends from static acoustic monitoring data using Paired Year Ratio Assessment (PYRA).
- Resource Type
- Academic Journal
- Authors
- Grist EPM; Chelonia Ltd., Mousehole, Cornwall, United Kingdom.; College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, United Kingdom.; McKinley TJ; College of Medicine and Health, University of Exeter, Exeter, United Kingdom.; Das S; College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, United Kingdom.; Institute for Data Science and Artificial Intelligence, University of Exeter, Exeter, United Kingdom.; Tregenza T; Centre for Ecology & Conservation, School of Biosciences, University of Exeter, Penryn, United Kingdom.; Jeffries A; Harbor Porpoise Project, Anacortes, Washington, United States of America.; Tregenza N; Chelonia Ltd., Mousehole, Cornwall, United Kingdom.
- Source
- Publisher: Public Library of Science Country of Publication: United States NLM ID: 101285081 Publication Model: eCollection Cited Medium: Internet ISSN: 1932-6203 (Electronic) Linking ISSN: 19326203 NLM ISO Abbreviation: PLoS One Subsets: MEDLINE
- Subject
- Language
- English
The cetacean conservationist is often faced with evaluating population trends from abundance data that are either sparse or recorded at different times in different years. The presence of diel or seasonal patterns in the data together with unplanned gaps is often problematic. Such data are typical of those obtained from static acoustic monitoring. We present a simple and transparent non-parametric trend evaluation method, 'Paired Year Ratio Assessment (PYRA)' that uses only whole days of data wherever they are present in each of successive pairs of periods of 365 days. We provide a quantitative comparison of the performance of PYRA with traditional generalised additive models (GAMS) and nonparametric randomisation tests that require a greater level of skill and experience for both application and interpretation. We conclude that PYRA is a powerful tool, particularly in the context of identifying population trends which is often the main aim of conservation-targeted acoustic monitoring.
Competing Interests: The authors have declared that no competing interests exist.