DOI: 10.5061/dryad.bcc2fqzs5
title: Feeding performance, kinematics and skills change with age in a granivorous songbird

description: Changes in neuromuscular performance due to maturation and ageing affect a
 wide range of motor behaviours in birds and mammals. The consequences may
 be especially pronounced during forceful and complex movements, such as
 feeding on seeds in songbirds, which require well-developed jaw muscles
 and fast, strongly coordinated beak and tongue movements. We investigated
 how feeding performance changes with age by filming juvenile and adult
 domestic canaries repeatedly over a span of two years with high-speed
 video. We extracted metrics of feeding performance, beak kinematics and
 seed handling skills of individuals during feeding on seeds with different
 characteristics. Age significantly affected several feeding metrics on the
 more challenging hemp seed, but not on the smaller and softer canary seed.
 Beak-opening frequency displayed a parabolic pattern, increasing early in
 life and slightly declining at old age, with no sex differences. Seed
 handling skills improved linearly with age and more strongly in males. The
 success rate of hemp seed husking also followed a parabolic pattern,
 improving in juveniles and declining in old age. Our results suggest that
 while learning and experience enhance feeding efficiency in early life,
 age-related declines may stem from reduced bite force or sensorimotor
 control deterioration.
description: # Feeding performance, kinematics and skills change with age in a
 granivorous songbird Dataset DOI:
 [10.5061/dryad.bcc2fqzs5](10.5061/dryad.bcc2fqzs5) ## Description of the
 data and file structure This dataset contains all the necessary data for
 reproducing the results of the research, as described in the manuscript
 with the name: 'Feeding performance, kinematics and skills change
 with age in a granivorous songbird' The data includes raw
 measurements obtained from both manual video analysis and automated beak
 tip tracking using DeepLabCut software, as well as the code for
 statistical analysis. In summary, this dataset includes: * 10 .csv files
 of raw measurements, each pertaining to a specific metric (or group of
 metrics), and 1 'master' .csv file ('age_summary')
 combining the data of the other 10 files. * an R-file with the code for
 statistical analyses and associated .txt files (see below; code/software).
 ### Files and variables #### General terminology (this is a list of terms
 that is used across most of the files): * bird: identification number of
 the individual * sex: sex of the individual (M = male, F = female) *
 birth_year: Year of birth of the individual * age_group: indicates whether
 the individual is a juvenile (young) or adult (adult) at the start of the
 experiments. * weight: Body mass of the individual prior to the experiment
 (in g) * session: A number from 1 to 4 indicating the recording session of
 the respective individual (individuals were recorded 4 times, every 6
 months over the course of 2 years). * NA: no data available because the
 individual refused to feed on the respective seed type or had died prior
 to the respective experiment. #### age_summary.csv: ##### this is the
 'master' file, which contains average values of all variables
 per individual of both seed types. This file was used for all statistical
 analyses. Terminology: * rec_date: date of the day the experiment was
 conducted on. * age_month: age of the individual at the time of the
 experiment in number of months. * seed: seed type the individual fed on
 (canseed = canary seed, hemp = hemp seed) * picking_duration: Average
 duration of the picking and head righting phase (in s) *
 cracking_duration: Average duration of the positioning and cracking phase
 (in s) * swallowing_duration: Average duration of the husk removal and
 swallowing phase (in s) * total_duration: Average duration of the entire
 feeding act (in s) * success_rate: Proportion of seed husking attempts
 that are successful (in %) * position: Average head position during seed
 cracking (number between 0 and 1) * splitting_seed: Proportion of
 successful seed husking attempts where the seed is being split in two
 halves (in %) * max_gape: Average maximum gape size (in mm) * min_gape:
 Average minimum gape size (in mm) * opening_velocity: Average maximum beak
 opening velocity (in mm/s) * closing_velocity: Average maximum beak
 closing velocity (in mm/s) * opening_acceleration: Average maximum beak
 opening acceleration (in mm/s²) * closing_acceleration: Average maximum
 beak closing acceleration (in mm/s²) * frequency: Average opening-closing
 frequency of the beak (in Hz) * amplitude: Average beak amplitude during
 opening-closing (in mm) #### cracking_mode_canary_age.csv &
 cracking_mode_hemp_age.csv: ##### these files list out the cracking mode
 during successful seed husking attempts in chronological order per
 individual, for canary seed and hemp seed respectively. Terminology: * S =
 seed splitting * C = seed crushing * splitting: Proportion of successful
 seed husking attempts where the seed is being split in two halves (in %) *
 crushing: Proportion of successful seed husking attempts where the seed is
 being crushed in irregular pieces (in %) #### head_position_canary_age.csv
 & head_position_hemp_age.csv: ##### these files list out the head
 position during successful seed husking attempts in chronological order
 per individual, for canary seed and hemp seed respectively. Terminology: *
 L = low head position * M = medium head position * H = high head position
 * position: Average head position during seed cracking (number between 0
 and 1) #### kinematics_canary_age.csv & kinematics_hemp_age.csv: #####
 these files contain kinematic variables extracted from 5 tracked feeding
 trials per individual, for canary seed and hemp seed respectively. *
 trial: number of the respective feeding trial * Frame range start:
 Starting frame of fragment of interest * Frame range end: Ending frame of
 fragment of interest * cut-off frequency: cut-off frequency for filtering
 (in Hz) * frequency fragment start time: Starting time for frequency
 calculation (in s), relative to fragment of interest * frequency fragment
 end time: Ending time for frequency calculation (in s), relative to
 fragment of interest * number of cycles: Number of opening-closing cycles
 from which frequency and amplitude are calculated * max gape: maximum gape
 size (in mm) * min gape: minimum gape size (in mm) * max opening velocity:
 Maximum beak opening velocity (in mm/s) * max closing velocity: Maximum
 beak clsoing velocity (in mm/s) * max opening acceleration: Maximum beak
 opening acceleration (in mm/s²) * max closing acceleration: Maximum beak
 closing acceleration (in mm/s²) * mean fragment frequency: average
 opening-closing frequency of fragment of interest (in Hz) * mean fragment
 amplitude: average beak amplitude during opening-closing of fragment of
 interest (in mm) #### phase_duration_canary_age.csv &
 phase_duration_hemp_age.csv: ##### these files contain phase durations of
 10 feeding trials per individual, for canary seed and hemp seed
 respectively. * trial: number of the respective feeding trial * picking:
 Duration of seed picking and head righting phase (in number of frames) *
 cracking: Duration of positioning and cracking phase (in number of frames)
 * swallowing: Duration of husk removal and swallowing phase (in number of
 frames) * total: Duration of the entire feeding act (in number of frames)
 #### success_rate_canary_age.csv & success_rate_hemp_age.csv: #####
 these files list out whether seed husking attempts are successful or not
 in chronological order per individual, for canary seed and hemp seed
 respectively. * V = success * X = failure * V_tot: Number of successful
 attempts * X_tot: Number of failed attempts * Rate: Proportion of seed
 husking attempts that are successful (in %) #### age.R: R-file detailing
 the mixed linear modelling and construction of graphs used in the
 manuscript. #### age_cans.txt: Text file containing the data during
 feeding on canary seed from age_summary.csv, ready to use in the R-script
 for the statistical analyses. #### age_hemp.txt: Text file containing the
 data during feeding on hemp seed from age_summary.csv, ready to use in the
 R-script for the statistical analyses. ## Code/software All statistical
 analyses were conducted in R (version 4.3.3). This dataset includes an
 R-file with the full script for the statistical analyses and generation of
 graphs. Additionally, .txt-files of the relevant data are included in this
 dataset, ready-to-use in the R-file. The required packages are:
 'lme4' and 'lmerTest' for linear mixed modelling, and
 'ggplot2' for graph generation. ## Access information All data
 is extracted from high-speed video recordings which are not publicly
 available due to their file size (+- 180 TB in total). These videos can be
 accessed upon request by contacting the corresponding author.