Spatiotemporal variation in harbor porpoise distribution and foraging across a landscape of fear

Williamson, L. D., Scott, B. E., Laxton, M. R., Bachl, F. E., Illian, J. B. , Brookes, K. L. and Thompson, P. M. (2022) Spatiotemporal variation in harbor porpoise distribution and foraging across a landscape of fear. Marine Mammal Science, 38(1), pp. 42-57. (doi: 10.1111/mms.12839)

Abstract

Understanding spatiotemporally varying animal distributions can inform ecological understanding of species' behavior (e.g., foraging and predator/prey interactions) and support development of management and conservation measures. Data from an array of echolocation‐click detectors (C‐PODs) were analyzed using Bayesian spatiotemporal modeling to investigate spatial and temporal variation in occurrence and foraging activity of harbor porpoises (Phocoena phocoena) and how this variation was influenced by daylight and presence of bottlenose dolphins (Tursiops truncatus). The probability of occurrence of porpoises was highest on an offshore sandbank, where the proportion of detections with foraging clicks was relatively low. The porpoises' overall distribution shifted throughout the summer and autumn, likely influenced by seasonal prey availability. Probability of porpoise occurrence was lowest in areas close to the coast, where dolphin detections were highest and declined prior to dolphin detection, leading potentially to avoidance of spatiotemporal overlap between porpoises and dolphins. Increased understanding of porpoises' seasonal distribution, key foraging areas, and their relationship with competitors can shed light on management options and potential interactions with offshore industries.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Laxton, Ms Megan and Illian, Professor Janine

Creator Roles

Laxton, M. R.: Formal analysis
Illian, J. B.: Supervision, Writing – review and editing

• Authors: Williamson, L. D., Scott, B. E., Laxton, M. R., Bachl, F. E., Illian, J. B., Brookes, K. L., and Thompson, P. M.
• College/School: College of Science and Engineering > School of Mathematics and Statistics > Statistics
• Journal Name: Marine Mammal Science
• Publisher: Wiley
• ISSN: 0824-0469
• ISSN (Online): 1748-7692
• Published Online: 15 June 2021
• Copyright Holders: Copyright © 2021 The Authors
• First Published: First published in Marine Mammal Science 38(1): 42-57
• Publisher Policy: Reproduced under a Creative Commons License