Harbour porpoises are flexible predators displaying context dependent foraging behaviours
Data files
Dec 04, 2024 version files 659.52 MB
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Data_Stedt_2024.xlsx
38.66 KB
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README.md
3.92 KB
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Video_supplement_Stedt_2024.mp4
659.36 MB
Abstract
Opportunistic mobile predators can adapt their behaviour to specific foraging scenarios, allowing them to target diverse prey resources. An interesting example is the harbour porpoise (Phocoena phocoena), a marine mammal with a huge energy demand feeding on a large variety of fish, squid and shrimps. Little is known about the foraging behaviour of harbour porpoises, as observations of wild specimens are notoriously difficult to obtain. In this study, foraging was identified in almost 60% of videos from UAV recordings in Danish coastal waters during daylight hours. Observations reveal them to be flexible predators, foraging on both single fish and schools of fish, as well as individually and in groups of varying size. We argue that some of the observed behavioural adaptations and context-dependent strategies for prey capture are based on information transfer and social learning. Our results provide unprecedented insights into the foraging behaviour of an opportunistic mammalian predator. Further, this study highlights the importance for porpoises to have access to coastal areas for energy acquisition, where they are in conflict with anthropogenic disturbances such as fisheries with the risk of by-catch.
README
README for Data_Stedt_2024.xlsx and Video_supplement_Stedt_2024.mp4
This readme file was generated on 2024-06-19 by Johanna Stedt
Last updated 2024-11-26
Data_Stedt_2024.xlsx
Extracted data from UAV recordings of harbour porpoises
Video_supplement_Stedt_2024.mp4
Video examples of the observed behaviours and foraging techniques described in Stedt et al. (2024)
Dataset and video file accompanies the paper
Stedt J., Hamel H., Torres Ortiz S., Højer Kristensen J. & Wahlberg M. (2024) Harbour porpoises are flexible predators displaying context dependent foraging behaviours. Ecology and Evolution.
GENERAL INFORMATION
Author/Principal Investigator Information
Name: Johanna Stedt
ORCID: 0000-0002-0994-9023
Institution: Lund University
Address: Department of Biology, SE-223 62 Lund, Sweden
Email: johanna.stedt@biol.lu.se
Period of data collection: September 2015 to September 2023
Method of data collection: quadcopter UAVs from the DJI Phantom and Mavic Series (models DJI 3, DJI 4 Pro 2.0 and Mavic III Classic)
Geographic location of data collection: coastal waters around Funen, Denmark
SHARING/ACCESS INFORMATION
Data and code published under Creative Commons Zero waiver (http://creativecommons.org/about/cc0). If you use any part of these data or code, please acknowledge the primary authors using the recommended citation given below.
Recommended citation for this dataset and video supplement:
Stedt et al., (2024) Harbour porpoises are flexible predators displaying context dependent foraging behaviours, Dryad, Dataset/Video supplement, https://doi.org/10.5061/dryad.dv41ns26k
METHODOLOGICAL INFORMATION
UAV raw output files were processed as described in the paper to produce the data file Data_Stedt_2024.xlsx.
Short representative sequences of observed behaviours and foraging techniques described in Stedt et al. (In press) were selected from raw UAV output files and combined into the video file Video_supplement_Stedt_2024.mp4 using iMovie.
DATA-SPECIFIC INFORMATION FOR: Data_Stedt_2024.xlsx
This file contains the complete extracted dataset of UAV sequences with harbour porpoises visible >20 seconds. The data have been processed in preparation for analysis as described in the paper.
The file Data_Stedt_2024.xlsx contains two data sheets: Non-foraging and Foraging.
SHEET-SPECIFIC INFORMATION FOR: Non-foraging
Number of variables: 6
Number of cases/rows: 227
Variable List:
ID: Individual identification number
Date: Date as YYYY-MM-DD.
Location: Geographic location for UAV recording
NrHP: Max number of observed individual harbour porpoises in the sequence
Calves: Max number of observed individual harbour porpoise calves in the sequence
Depth: Depth category (shallow/deep/shallow + deep, shallow: 0-5m, deep: >5m)
SHEET-SPECIFIC INFORMATION FOR: Foraging
Number of variables: 15
Number of cases/rows: 314
Variable List:
ID: Individual identification number
Date: Date as YYYY-MM-DD.
Location: Geographic location for UAV recording
NrHP: Max number of observed individual harbour porpoises in the sequence
Calves: Max number of observed individual harbour porpoise calves in the sequence
Depth: Depth category (shallow/deep/shallow + deep, shallow: 0-5m, deep: >5m)
PreyVis: Prey visibility (1/0, 1=yes, 0=no)
PreyType: Observed prey type (single/school/single + school/na, na = prey not visible)
Cruise: Foraging mode cruise search observed (1/0, 1=yes, 0=no)
Bottom: Foraging mode bottom search observed (1/0, 1=yes, 0=no)
Split: Foraging mode split observed (1/0, 1=yes, 0=no)
Chase: Foraging mode chase observed (1/0, 1=yes, 0=no)
Turn: Foraging mode turn observed (1/0, 1=yes, 0=no)
Herd: Foraging mode herd observed (1/0, 1=yes, 0=no)
Catch: Foraging mode catch observed (1/0, 1=yes, 0=no)