10.5061/DRYAD.VMCVDNCTS
Ersoy, Selin
0000-0003-4657-4360
Royal Netherlands Institute for Sea Research
Beardsworth, Christine
Royal Netherlands Institute for Sea Research
Dekinga, Anne
Royal Netherlands Institute for Sea Research
van der Meer, Marcel
Royal Netherlands Institute for Sea Research
Piersma, Theunis
Royal Netherlands Institute for Sea Research
Groothuis, Ton
University of Groningen
Bijleveld, Allert
Royal Netherlands Institute for Sea Research
Exploration speed in captivity predicts foraging tactics and diet in
free-living red knots
Dryad
dataset
2021
foraging tactics
individual niche specialisation
stable isotope analysis
pace-of-life
2021-11-15T00:00:00Z
2021-11-15T00:00:00Z
en
60220 bytes
4
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Variation in foraging tactics and diet are usually attributed to
differences in morphology, experience, and prey availability. Recently,
consistent individual differences in behaviour (personality) have been
shown to be associated with foraging strategies. Bolder or more
exploratory individuals are predicted to have a faster pace-of-life and
offset the costs of moving more or in risky areas, with higher energetic
gains by encountering profitable foraging opportunities and prey. However,
the relationship between personality, foraging, and diet is poorly
understood. We investigated how exploratory behaviour in red knots
(Calidris canutus) is associated with foraging tactics and diet by
combining laboratory experiments, field observations, and stable isotope
analysis. First, we developed a mobile experimental arena to measure
exploration speed in controlled settings. We validated the method by
repeated testing of individuals over time and contexts. This setup allowed
us to measure exploratory personality at the field site, eliminating the
need to bring birds into captivity for long periods of time. After
releasing birds within days of their capture, we asked whether exploration
speed was associated with differences in foraging tactics and diet in the
wild. We found that tactile foraging red knots mainly caught hard-shelled
prey that are buried in the sediment, whereas visual foraging knots only
captured soft preys located close to or on the surface. We also found that
faster explorers showed a higher percentage of visual foraging than slower
explorers. By contrast, morphology (bill length and gizzard size) had no
significant effect on foraging tactics. Diet analysis based on δ15N and
δ13C stable isotope values of plasma and red blood cells confirmed our
field observations with slower explorers mainly consumed hard-shelled prey
while faster explorers consumed more soft than hard-shelled prey. Our
results show that foraging tactics and diet are associated with a
personality trait, independent of morphological differences. We discuss
how consistent behaviour might develop early in life through positive
feedbacks between foraging tactics, prey type, and foraging efficiency.
Isotope data: Red blood cell and plasma d13C and d15N isotopes collected
from the blood samples of red knots. Exploration speed: Movement
tracjectories were collected from the recordings of the top camera during
experiments in the mobile arena. We used the distance between estimated
positions to calculate speed. Errors in the positioning algorithm were
filtered by excluding speeds higher than 200 cm/s. An individual’s
exploration speed was calculated as the average speed during each 20 min
trial. The dataset includes four repeats of exploration speed. Proportion
of explorative behaviour: Behaviours were collected from the recording of
the side camera during experiments in indoor arena and mobile arena.
Behavioural budget is calculated of the time that the focal bird spend
exploring (walking and probing) the arena. Foraging behaviour: Foraging
behaviour was collected from the observations in the field. Focal birds
were filmed for 20 min or up to the moment they flew away. Behavioural
budget is calculated for two types of foraging tactics: ‘tactile foraging’
when a bird is probing continuously with the bill into the substrate, and
‘visual foraging’ when a bird is scanning the area in front of it and
pecking at items seen on the substrate surface. Prey-foraging behaviour:
In cases that we could identify the ingested prey in the
field, categorized as hard-shelled prey (e.g., cockles or Baltic tellins)
or soft prey (e.g., brown shrimp or polychaete worms) to investigate the
relationship between foraging tactics and diet.
GENERAL INFORMATION 1. Titles of the Dataset: Exploration speed (mean
speed cm/sec) in mobile arena, exploration behaviour (behavioural budget
walking and probing), isotope data (plasma and red blood cell), foraging
behaviour collected from the observations in the field 2. Date of the data
collection: Catching between 14 August - 19 September 2018, and 1 August -
6 September 2019, Field observations from August to October 2019 3.
Geographic location of data collection: Western Dutch Wadden Sea
(53°15'N, 5°15'E) 4. Corresponding author information: Selin
Ersoy, NIOZ Royal Netherlands Institute for Sea Research, Department of
Coastal Systems, PO Box 59, 1790 AB Den Burg, Texel, The Netherlands,
selin.ersoy@gmail.com 5. Link to publication: Ersoy et al. (2021)
Exploration speed in captivity predicts foraging tactics and diet in
free-living red knots. Journal of Animal Ecology DATA & FILE
OVERVIEW DATA & FILE OVERVIEW 1. KnotData.csv: Metadata of
individual red knots Column 1: CaptureDate: The date when the red
knots were captured by means of mist-netting in the Western Duthc Wadden
Sea (53°15'N, 5°15'E) Column 2: RingNr: Unique metal
ring number of red knots. Ring were put on the legs Column 3:
Crc: Unique combination of color-rings of red knots. Rings were placed on
the legs (two in right and two in left legs) Column 4: Bill: Bill
lenght of the individual in mm. Column 5: Mass: Body mass of the
individual in gr. Column 6: cell_d15N: Isotope value from red
blood cell d15N. Column 7: cell_d13C: Isotope value from red
blood cell d13C. Column 8: plasma_d15N: Isotope value from blood
plasma d15N. Column 9: plasma_d13C: Isotope value from blood
plasma d13C. Column 10: Expl_F01_MeanSpeed: Exploratory
personality score of individual measured in mobile arena for the first
time (mean speed cm/sec) Column 11: Expl_F01_Log10MeanSpeed:
Log10 transformed of the exploratory personality score of individual
measured in mobile arena for the first time (mean speed cm/sec)
Column 12: Expl_Date: The date that exploratory personality assay was
conducted 2. ExplorationSpeedRepeatibility.csv: Data on repeated
measurement (max. 4 repeats) on exploration speed (mean speed log10
cm/sec) measured in the mobile arena Column 1: RingNr: Unique
metal ring number of red knots. Ring were put on the legs Column
2: MeanSpeed: Exploratory personality score of individual measured in
mobile arena (mean speed cm/sec) Column 3: Expl_Date: The date
that exploratory personality assay was conducted Column 4:
Condition: Whether the individual bird was wildly captured or it was in
captivity Column 5: Repeat_Nu: Repeat number of the personality
assay trials 3. ExplorationValidation.cvs: Data on personality
measurements on both mobile (FU) and indoor (WU) arenas. Exploration is
scored both mean speed and behavioural budget as proportion of walking and
probing Column 1: RingNr: Unique metal ring number of red knots.
Ring were put on the legs Column 2: Expl_Date: The date that
exploratory personality assay was conducted Column 3: Setup:
Whether the personality was measured in mobile (FU) or indoor (WU) arenas.
Column 4: Condition: Whether the individual bird was wildly
captured or it was in captivity Column 5: PropExplBehaviour:
Exploratory personality scored as behavioural budget as proportion of
walking and probing Column 6: Mean_Expl_Speed: Exploratory
personality scored as movement speed 4. ForagingFieldData.csv: Data on
proportion of foraging tactics (tactile and visual) observed in the
field. Column 1: RingNr: Unique metal ring number of red knots.
Ring were put on the legs Column 2: Expl_F01_MeanSpeed:
Exploratory personality score of individual measured in mobile arena for
the first time (mean speed cm/sec) Column 3: gizzard_size:
Gizzard size of the individual red knots measured through ultrasound
(following Dekinga et al., 2001) Column 4: bill_length: Bill
lenght of the individual in mm. Column 5: p_visual: Proportion of
visual foraging observed in the field Column 6: p_tactile:
Proportion of tactile foraging observed in the field 5.
PreyForagingBehv.csv: Data on which foraging tactic (tactile and visual)
result in catching what type of prey (soft and hard-shelled) observed in
the field. Column 1: Obs_id: Field observation id. Combination of
colour ring combination (crc) and the date of observation. Column
2: totalingested_prey: Number of total ingested prey observed from that
observation Column 3: prey_type: Identified type of prey
(shellfish, worm, shrimp, cockle) Column 4: Foraging: What types
of foraging behaviour was observed during that ingestion (tactile vs
visual) Column 5: Prey: Whether that prey type is hard-shelled or
soft prey