Data and code from: Characterization of cooperative feeding dynamics and a novel acoustic indicator of prey capture in herring-eating killer whales

Group hunting is a widespread phenomenon, fundamentally shaping predator
social dynamics and trophic interactions with their prey. The foraging
behaviour of killer whale (Orcinus orca) groups feeding upon herring has
been described as cooperative. In this study, we used animal-borne audio
and video data to evaluate cooperative interactions and feeding rates of
herring-eating killer whales in Icelandic waters. From video observations,
whales appeared to stop herding herring following a tail-slap, feeding
close to one another on individual stunned herring. By-product mutualism
was identified, as whales consumed herring regardless of whether or not
they conducted the tail-slap. A “slurping” sound was recorded during 26 %
of video-confirmed consumption events, enabling us to estimate a mean (±
s.d.) of 29.7 ± 25.3 herring consumed per tail-slap by the foraging group.
Role specialisation was indicated, with three tagged whales repeatedly
occupying the “tail-slapping” role over the duration of video recording
periods. Only 8 % of visually-observed prey consumption events occurred in
the absence of tail-slaps (“whole-body attacks”), indicating the
cooperative tail-slap feeding is more efficient than whole body attacks.
Our study confirms the highly social and cooperative nature of tail-slap
feeding by killer whale groups, and provides a novel method to estimate
group-level feeding rates.

# Data and code from: Characterization of cooperative feeding dynamics and
a novel acoustic indicator of prey capture in herring-eating killer whales
Dataset DOI: [10.5061/dryad.tmpg4f59x](10.5061/dryad.tmpg4f59x) ##
Description of the data and file structure Dataset contains .csv files and
R code necessary to run analyses to extract and summarise aspects of
feeding behaviour in herring-eating killer whales (*Orcinus orca*) in
Icelandic waters from animal-borne video data, to acoustically
characterise suction feeding sounds ("slurps") produced by
whales when suction feeding on herring from animal-borne hydrophones, and
to estimate group-level feeding rates from slurp occurrence. Files
included also include .csv files and R code necessary to run inter-rater
reliability (IRR) statistics on video and audio scores by mutliple
scorers, as well as the code to run a role-taking analysis of
tail-slapping behaviour. ### Files and variables #### File: IRR_audio.zip
**Description:** Folder contains the .csv files necessary to run IRR
statistics on audio data annotated for "slurping" sounds by two
separate scorers. "COUNTallslurp.csv" and
"COUNTslurph.csv" contain counts of the number of occurrences of
slurps within 5-second time bins, within discrete foraging dives, for all
slurps and only high-confidence slurps respectively, within 5-second time
bins within discrete foraging dives. "countsSLURPALL.csv" and
"countsSLURPH.csv" contain counts of the number of occurrences
of slurps across the entirety of discrete foraging dives, for all slurps
and only high-confidence slurps respectively. "PAallslurp.csv"
and "PAslurph.csv" contain the presence/absence of slurps within
5-second time bins, within discrete foraging dives, for all slurps and
only high-confidence slurps respectively. #### File: IRR_video.zip
**Description:** Folder contains the .csv files necessary to run IRR
statistics on video data scored for data scored by two
(2*_*raters_222324 sub-folder) and three
(3*_*raters_22 sub-folder). In the two-raters folder
(2*_*raters_222324), "HCFPC_2R_222324.csv",
"HCNPC_2R_222324.csv" and "NonfocalTS_2R_222324.csv"
contain the presence/absence of scores with 5-second time bins, for
high-confidence focal prey consumption, high-confidence non-focal prey
consumption and non-focal tail-slap scores, respectively.
"fish_2R_222324.csv" contains the presence/absence of fish seen
scores with 1-minute time bins. "counts_HCFPC_2R_222324.csv" and
"counts_HCNPC_2R_222324.csv" contain the counts of number of
occurrences of high-confidence prey consumption scores within 5-second
time bins, for focal and non-focal events respectively. In the
three-raters folder (3*_*raters_22),
"FPC_3R_22.csv" and "NPC_3R_22.csv" contain the
presence/absence of prey consumption events within 5-second time bins, for
focal and non-focal events respectively. "fish_3R_22.csv"
contains the presence/absence of fish seen scores within 1-minute time
bins. "counts_FPC_3R_22.csv" and
"counts_NPC_3R_22.csv" contain the counts of number of
occurrences of prey consumption events within 5-second time bins, for
focal and non-focal events respectively. #### File: NonFocal_slurps.csv
**Description:** Contains acoustic parameter measurements for slurps which
were not video-confirmed to be produced by the tagged whale. #####
Variables * ID: Identifier for each non-focal slurp. * Deployment: Tag
deployment during which slurp was recorded. * Low_Freq_Hz: Lower-frequency
bound of selection area within which acoustic parameters were measured for
each slurp. * High_Freq_Hz: Upper-frequency bound of selection area within
which acoustic parameters were measured for each slurp. * Dur_90_s: 90 %
energy duration for each slurp. * Inband_Power_dBFS: Inband power measure
for each slurp. * Noise_Inband_Power_dBFS: Inband power measure for
section of background noise without slurp similar to background noise
during slurp. * Center_Freq_Hz: Centre frequency measure for each slurp. *
Freq_25_Hz: 25 % energy frequency measure for each slurp. * Freq_75_Hz: 75
% energy frequency measure for each slurp. #### File: TS_scores.csv
**Description:** Video scores recorded during and characteristics of each
individual tail-slap (TS) event. ##### Variables * TS_id: Identifier for
each individual TS event. * deployment: Tag deployment during which each
TS event occurred. * duration: Duration of TS event in seconds, from
moment of TS to next surfacing or next TS. * slurp_count: Number of
occurrences of all slurps (low + high confidence) during each TS event. *
slurp_h_count: Number of occurrences of only high confidence slurps during
each TS event. * ts_whale: Whale identified to be performing the TS. *
n_ts_whale: Number of whales performing the TS. * limited_vis: Whether
visibility was limiting at any point during a TS event (yes(y)/no(n)). *
limited_fov: Whether field-of-view was limiting at any point during a TS
event (yes(y)/no(n)). * TS_whale_eat: Whether the whale(s) that performed
the TS was also observed to consume a fish during the same TS event. ####
File: binomil_slurp_per_pc.csv **Description:** Data necessary to run
models to assess potential drivers of variation in slurp production. Each
row corresponds to a high-confidence prey consumption event. #####
Variables * deployment: Tag deployment during which each prey consumption
event occurred. * slurp: Whether this prey consumption event was
accompanied by a slurp (1 = yes, 0 = no). * pc_whale: Whether the whale
consuming a prey was the tagged whale (f) or a non-tagged whale (n). *
time_s: Time since start of tag deployment at which the prey consumption
event occurred, in seconds. * depth: Depth of tagged whale at time at
which each prey consumption event occurred, in metres. * daytime_hour:
Time of day at which each prey consumption event occurred, in hours. *
daytime_min: Time of day at which each prey consumption event occurred, in
minutes. * daytime_sec: Time of day at which each prey consumption event
occurred, in seconds. * class: Age/sex class of each tagged whale for each
deployment (male, female, juvenile, other or young) * size: Age/sex size
class of each tagged whale for each deployment (male vs other vs calf) *
age: Age class of each tagged whale for each deployment (adult vs young vs
other) * vis: Visibility score (from 0-255) for each prey consumption
event. * n_visPC_TS: Total number of visually-confirmed prey consumption
events which occurred during the same tail-slap as the prey consumption
event. * n_visPC_dep: Total number of visually-confirmed prey consumption
events which occurred during the same deployment as the prey consumption
event. #### File: Focal_slurps.csv **Description:** Contains acoustic
parameter measurements for slurps which were not video-confirmed to be
produced by the tagged whale. ##### Variables * ID: Identifier for each
focal slurp. * Deployment: Tag deployment during which slurp was recorded.
- Low_Freq_Hz: Lower-frequency bound of selection area within which
acoustic parameters were measured for each slurp. - High_Freq_Hz:
Upper-frequency bound of selection area within which acoustic parameters
were measured for each slurp. - Dur_90_s: 90 % energy duration for each
slurp. - Inband_Power_dBFS: Inband power measure for each slurp. -
Noise_Inband_Power_dBFS: Inband power measure for section of background
noise without slurp similar to background noise during slurp. -
Center_Freq_Hz: Centre frequency measure for each slurp. - Freq_25_Hz: 25
% energy frequency measure for each slurp. - Freq_75_Hz: 75 % energy
frequency measure for each slurp. #### File: FD_scores.csv
**Description:** Video scores recorded during and characteristics of each
individual foraging dive (FD). ##### Variables * Year: Year during which
tag deployment occurred. * Deployment: Tag deployment during which each FD
occurred. * Video Segment: Continuous video segment during which each FD
occurred. * Foraging Dive: Number of foraging dive within each video
segment. * Start: Start time of foraging dives in seconds from start of
video segment. * End: End time of foraging dives in seconds from start of
video segment. * Duration: Duration of each foraging dive in seconds. *
Limited Vis: Whether visibility was limiting at any point during a FD
(yes(y)/no(n)). * Limited FOV: Whether field-of-view was limiting at any
point during a FD (yes(y)/no(n)). * TS_count: Number of acoustically
detected TS during each FD. * SLURP_count: Number of occurrences of all
slurps (low + high confidence) during each FD. * SLURP_H_count: Number of
occurrences of high-confidence slurps during each FD. * vs_TS_PA:
Presence/absence of visually-confirmed TS during each FD. * vis_TS_count:
Number of visually-confirmed TS during each FD. * N TS whales: Number of
whales performing TS during each FD. * TS whale: Whale identified to be
performing the TS during each FD. * TS whale eat: Whether the whale(s)
that performed the TS was also observed to consume a fish during the same
TS event in each FD. * Focal_HC_PC: Presence/absence of high-confidence
prey consumption events by the tagged whale in each FD. * Min Number of
Foraging whales: Minimum number of whales seen to be consuming fish during
each FD (excluding the tagged whale). * PP_PA: Presence/absence of prey
processing and partial prey consumption during each FD. * vis_F_HCPC:
Number of visually confirmed high-confidence prey consumption events by
the tagged whale during each FD. * vis_NF_HCPC: Number of visually
confirmed high-confidence prey consumption events by non-tagged whales
during each FD. * vis_HCPC: Number of visually confirmed high-confidence
prey consumption events any whale during each FD. * PC_with_slurp: Number
of visually confirmed high-confidence prey consumption events occurring
concurrently with a slurp during each FD. #### File:
individual_tscounts.csv **Description:** Number of tail-slap events
detected during each feeding bout, including focal tail-slaps, as well as
minimum and maximum group size estimates for each feeding bout. #####
Variables * dep: Deployment ID for each feeding bout. * fb: Indication of
whether the feeding bout is the first (1) or second (2) feeding bout in
each deployment. * fb_id: Feeding bout ID. * n_tsvents: The number of TS
events detected within each feeding bout. n_focalts: The number of focal
TS events detected within each feeding bout. * min_n: Minimum group size
estimate for each feeding bout. * max_n: Maximum group size estimate for
each feeding bout. #### File: IRR_statistics.R **Description:** This code
runs the IRR statistical tests for the audio and video data contained
within the IRR_audio.zip and IRR_video.zip folders respectively. ####
File: Videoscores_summary.R **Description:** The first part of this code
extracts and summarises relevant information from video scores within both
discrete foraging dives (FD) and tail-slaps (TS). The second part of this
code calculates the proportion of PCs accompanied by a slurp, and applies
this to estimate group-level feeding rates. #### File:
Acoustic_Slurps_Analysis.R **Description:** This code calculates source
levels and runs descriptive stats on measurement outputs from Raven. ####
File: Drivers_of_variation.R **Description:** This code runs models to
assess potential drivers of variation in slurp production. #### File:
Role-taking_analysis.R **Description:** This code runs the role-taking
analysis of tail-slapping behaviour, simulating an expected distribution
of tail-slaps by the focal whale for each feeding bout and comparing it to
the observed tail-slapping behaviour. ## Code/software R was utilised for
all analyses, with code provided. Libraries necessary are
"dplyr", "irr", "lme4" and
"MuMIn".