Data from: Use and prevalence of novel bubble-net foraging strategy in Western Antarctic humpback whales
Data files
Aug 19, 2024 version files 238.30 KB
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Allen_et_al_2024_MEPS_-_Data_Final.xlsx
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README.md
Abstract
The innovation of new foraging strategies allows species to optimize their foraging in response to changing conditions. Humpback whales provide a good study species for this concept, as they utilize multiple novel foraging tactics across populations in diverse environments. Bubble-net feeding (BNF), commonly seen in the Northern Hemisphere, has emerged as a foraging innovation in the past 20 yr within the Western Antarctic Peninsula. Using sightings data from 2015–2023, we found that BNF was present in every study year, with an annual average of 30% of foraging sightings. This data was supplemented with 26 animal-born tags deployed over the same study period. Of these tags, 12 detected instances of BNF, making up an average of 19% of the foraging tactics detected. There were seasonal trends in BNF sightings, as it was observed significantly more often at the beginning of the feeding season (January) before declining. BNF group sizes (mean: 3.41) were significantly larger than non-BNF surface feeding groups (mean: 2.21). This observation is consistent with BNF in the Northern Hemisphere, which also appears to primarily be a group foraging strategy. The seasonal pattern and relatively recent emergence of BNF suggests that its use is likely tied to specific environmental conditions, which should be investigated by comparing BNF with variables such as prey density and light availability. The social transmission of novel foraging strategies across other populations further suggests that the prevalence of this strategy likely occurs through social learning.
README
GENERAL INFORMATION
1. Title: Use and prevalence of novel bubble-net foraging strategy in Western Antarctic humpback whales
2. Co-authors: Jenny A. Allen*, Ross C. Nichols, Logan J. Pallin, David W. Johnston, Ari S. Friedlaender
*contact: jallen10@ucsc.edu
3. Data collection: Western Antarctic Peninsula, Antarctica (2015-2023)
4. Funding sources: the National Science Foundation Office of Polar Programs (Postdoctoral Fellowship 2218949 and Grants 1643877, ANT-07-39483, 1250208, and 1440435), the Palmer Long-Term Ecological Research Program (Grants 1440435 and 2026045), the Winifred Violet Scott Trust, the National Geographic Society (NGS-909906R-21), the Marine Mammal Commission, World Wide Fund for Nature–Australia (WWF–Australia), The International Whaling Commission’s Southern Ocean Research Partnership (P0710, 0711-02), the US Biological Adaptations to Environmental Change in Antarctica, the Scientific Committee of Antarctic Research (SCAR)
5. Data citation: Allen et al. (2024). Data from: Use and prevalence of novel bubble-net foraging strategy in Western Antarctic humpback whales, Dryad, Dataset
DATA OVERVIEW
The data consists of a summary of the sightings ands animal-borne tag data collected between 2015 and 2023 during the National Science Foundation Long-Term Ecological Research (LTER) Study. These data all pertain to humpback whales and were collected along the Western Antarctic Peninsula. The animal-borne tags used were Customized Animal Tracking Solutions (CATS) tags, fitted with video recorder and 3-D sensors.
SIGHTING RECORDS DATA
These data are a summary of the data collected via boat-based surveys aboard zodiacs launched from either Palmer Station or during research surveys aboard the Laurence M Gould (LMG). Each row is a unique sighting, defined as a group of associated whales that were sighted and or approached during surveys.
Number of variables: 12
Number of rows: 1108
Missing data: Lat & Long (36 each), Group_size (11), NA
Variable list:
Platform: Whether data were collected at Palmer Station (Palmer) or aboard the Laurence M Gould (LMG)
Season: The season over which data were collected, as seasons cover December-April and thus include two years
Date: Date of the sighting record
Time: Time of sighting without date
Lat: Distance south of the equator, measured in decimal degrees
Long: Distance east or west of the meridian, measured in decimal degrees
Daily Sighting Count The number sighting for that date (i.e., 1 is the first sighting of the day)
Group_size: The number of individuals within the sighting
Calves: The number of calves within the sighting
Feeding: Whether feeding took place during the sighting
OSF: "Other Surface Feeding"; Whether any surface feeding strategy other than bubble net feeding was observed during the sighting
BNF: "Bubble-Net Feeding"; Whether bubble net feeding was observed during the sighting
TAG RECORDS DATA
These data are a summary of the data collected via animal-borne CATS tags, deployed onto humpback whales from zodiacs launched from either Palmer Station or during research surveys aboard the Laurence M Gould (LMG). Each row is a unique tag deployment, defined as a tag successfully deployed onto a single animal and retrieved. Data refer to both information identified within the video footage from the tag, as well as the sensors within the tag.
Number of variables: 9
Number of rows: 9
Missing data: NA
Variable list:
Deployment ID: Unique identifier for each tag deployment
Month: The numerical month in which the tag was deployed
Year: The year in which the tag was deployed
TotalVideoAudted_s: Total amount of video footage audited for bubble events in seconds
N_BN: Total number of bubble events detected in video footage (note that these include events less than 7s in duration, which were removed during analyses)
FRate_h_BN: Hourly feeding rate (lunges/hr) for bubble net feeding, calculated by detected lunges during bubble events
N_L: Total number of lunges detected by tag sensors (inclusive of those detected during bubble events)
FRate_h_L: Hourly feeding rate (lunges/hr), calculated by detected lunges regardless of foraging strategy
BN Durations: 1-252: Duration in seconds of each individual bubble event detected in video footage. Bubble events are numbered 1-252 as a count of the total number of bubble events for that deployment (i.e., BN Durations_1 is the first bubble event for that deployment, BN Durations_2 is the second bubble event, etc). NA indicates that there was no bubble event of that count (i.e., if a deployment only had 5 bubble events, then BN Durations_6 and beyond are listed as NA).
BUBBLE EVENT DATA
These data are a summary of the identified bubble events detected within animal-borne CATS tags. Each row is a unique bubble event, detected as per Allen et al. 2024 by expert auditing of tag video footage. Depth and time data are taken from sensors within the tags.
Number of variables: 4
Number of rows: 494
Missing data: None
Variable list:
Deployment ID: Unique identifier for each tag deployment
Start Depth: Depth at which the first bubble in the bubble event was detected
Stop Depth: Depth at which the last bubble in the bubble event was detected
Duration: The length in seconds of the bubble event