DOI: 10.5061/dryad.zkh1893js
title: Data from: Use and prevalence of novel bubble-net foraging strategy in Western Antarctic humpback whales

description: 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.
description: 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 ```