Data from: Stunned by a heatwave: Experimental heatwaves alter juvenile responsiveness to the threat of predation
Data files
May 23, 2025 version files 232.22 KB
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DataHeatwave.zip
224.33 KB
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README.md
7.90 KB
Abstract
Heatwaves, increasingly prevalent in our rapidly changing climate, significantly impact animals with far-reaching ecological and evolutionary consequences. One of the first responses in animals to stress, including heat stress, is behavioural change, and this can directly influence fitness and survival. Changes in anti-predator behaviour are particularly critical, as they may compromise a prey’s ability to evade predators, thus increasing predation risk and jeopardizing survival. In the context of climate change, assessing anti-predator reactions under ecologically relevant heat stress is thus crucial, especially during the vulnerable life stage of development. This study investigated the effects of a heatwave on anti-predator responses in juvenile guppies (Poecilia reticulata). One-month-old guppies were subjected to a 5-day experimental heatwave (32°C) or a control temperature (26°C). After the treatment, all individuals were tested at a common temperature (26°C) for anti-predator behavioural responses and swimming performance, the latter serving as a proxy for physical condition. While heatwave exposure did not affect swimming performance, it significantly altered anti-predator responses. Heatwave-exposed juveniles exhibited a reduced freezing response and faster resumption of normal activity compared to control fish. Our findings demonstrate that heatwaves can modify prey’s anti-predator behaviours during critical developmental stages. This suggests that heatwaves may increase predation risk, potentially impacting survival rates and reshaping predator-prey interactions in the face of ongoing climate change.
https://doi.org/10.5061/dryad.gb5mkkx13
Description of the data and file structure
We investigated the effects of an experimental heatwave during development on anti-predator responses in juveniles, using the guppy, Poecilia reticulata, as model species. Following heatwave (or control) exposure, we tested each individual’s anti-predator behaviour in an open field set up, in response to a visual and an olfactory predator cue. In addition to the anti-predator response, we measured swimming endurance, which is associated with body condition, using a flow chamber, and performed a ‘capture test’ to estimate the fish’s physical ability to evade an approaching predator.
Files and variables
File: DataHeatwave.zip
Description: The file contains 5 datasets and 1 R code. The variables within each dataset are described within the R code File, which also contains analyses.
Missing values are indicated by "NA".
1_OpenField_visual.cvs - The overall response to a visual stimulus (in terms of distance moved, freezing time, and swimming velocity) in an open field, of juvenile fish previously exposed to a heatwave or control treatment.
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Variables in the dataset:
# LineID : Line ID; just for ordering the data
# FishID : individual ID of each fish
# FamilyID : ID of the family (fish from the same family/mother)
# Tank : ID of Tank in which 4 siblings were raised together
# Treatment : Heatwave or Control treatment
# Container : Treatment tank, that is, the container in which the fish were during te temperature treatment
# TotDistMinute : total distance moved in cm
# NrSecsFrozenMinute : seconds that fish was frozen (velocity was less than 1cm/s)
# NrSecsMovingMinute : seconds that fish was moving
# MeanVelMinWhenMoving: swimming speed – mean velocity in cm/s when fish was moving
# SL : standard length of fish (in mm)
# Weight : weight of the fish (in g)
# FultonBodCond : Fulton's index of body condition (in mg*mm–3)
2_OpenField_olfactory_mean_response.cvs - The overall response to an olfactory stimulus (in terms of distance moved, freezing time, and swimming velocity) in an open field, of juvenile fish previously exposed to a heatwave or control treatment.
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Variables in the dataset:
# Line ID; just for ordering the data
# FishID : individual ID of each fish
# FamilyID : ID of the family (fish from the same family/mother)
# Tank : ID of Tank in which 4 siblings were raised together
# Treatment : Heatwave or Control treatment
# Container : Treatment tank, that is, the container in which the fish were during te temperature treatment
# Phase : Undisturbed or predator phase
# TotDistMoved : total distance moved in cm
# NrSecsFrozen : seconds that fish was frozen (velocity was less than 1cm/s)
# NrSecsMoving : seconds that fish was moving
# MeanVelMoving : swimming speed – mean velocity in cm/s when fish was moving
# SL : standard length of fish (in mm)
# Weight : weight of the fish (in g)
# FultonBodCond : Fulton's index of body condition (in mg*mm–3)
3_OpenField_olfactory_temporal_response_PREDATOR.cvs - The temporal response to an olfactory stimulus (in terms of distance moved, freezing time, and swimming velocity) in an open field, of juvenile fish previously exposed to a heatwave or control treatment.
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Variables in the dataset:
# Line ID : just for ordering the data
# FishID : individual ID of each fish
# FamilyID : ID of the family (fish from the same family/mother)
# Tank : ID of Tank in which 4 siblings were raised together
# Treatment : Heatwave or Control treatment
# Container : Treatment tank, that is, the container in which the fish were during te temperature treatment
# Phase : Undisturbed or predator phase (Here all Predator)
# Time : Time in 10 seconds units during the phase
# TotDistMovedTenSec : total distance moved in cm
# NSecsFreezingTenSec : seconds that fish was frozen (velocity was less than 1cm/s)
# NSecsMovingTenSec : seconds that fish was moving
# MeanVelTenSecMoving : swimming speed – mean velocity in cm/s when fish was moving
# SL : standard length of fish (in mm)
# Weight : weight of the fish (in g)
# FultonBodCond : Fulton's index of body condition (in mg*mm–3)
4_OpenField_olfactory_temporal_response_UNDISTURBED.cvs - The temporal response in a control period without a stimulus (in terms of distance moved, freezing time, and swimming velocity) in an open field, of juvenile fish previously exposed to a heatwave or control treatment.
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Variables in the dataset:
#Line ID : just for ordering the data
# FishID : individual ID of each fish
# FamilyID : ID of the family (fish from the same family/mother)
# Tank : ID of Tank in which 4 siblings were raised together
# Treatment : Heatwave or Control treatment
# Container : Treatment tank, that is, the container in which the fish were during the temperature treatment
# Phase : Undisturbed or predator phase (Here all Undisturbed)
# Time : Time in 10 seconds units during the phase
# TotDistMovedTenSec : total distance moved in cm
# NSecsFreezingTenSec : seconds that fish was frozen (velocity was less than 1cm/s)
# NSecsMovingTenSec : seconds that fish was moving
# MeanVelTenSecMoving : swimming speed – mean velocity in cm/s when fish was moving
# SL : standard length of fish (in mm)
# Weight : weight of the fish (in g)
# FultonBodCond : Fulton's index of body condition (in mg*mm–3)
5_Capture_and_Flow_chamber.cvs - The performance in a capture test and in a flow chamber test of juvenile fish previously exposed to a heatwave or a control treatment.
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Variables in the dataset:
# Line ID : just for ordering the data
# FishID : individual ID of each fish
# FamilyID : ID of the family (fish from the same family/mother)
# Tank : ID of Tank in which 4 siblings were raised together
# Treatment : Heatwave or Control treatment
# Container : Treatment tank, that is, the container in which the fish were during the temperature treatment...
# Weight : weight of the fish (in g)
# SL : standard length of fish (in mm)
# Capture_minutes : Minute in which the fish was captured
# Capture_seconds : Second (within minute above) in which the fish was captured
# Capture_time : Total time taken until (in seconds) until the fish was captured
# Flow_minutes : Minute in which the fish was swept out of the chamber
# Flow_seconds : Second (within minute above) in which the fish was swept out of the chamber
# Flow_time : Total swimming time in the flow chamber (in seconds)
# Flow_setting : Highest water velocity reached
# FultonBodCond : Fulton's index of body condition (in mg*mm–3)
Code/software
R can be used to open the code and load the csv.s files. The following packages were used in the code: lme4, car, lmerTest, blmeco, effects.
We tested whether a heatwave affects anti-predator responses in one-month-old juvenile P. reticulata using a split clutch approach, where siblings were randomly assigned to either the treatment (heatwave) or the control. Following the heatwave (or control) exposure, we tested each individual’s anti-predator behaviour at a common temperature (26°C) in an open field set up, in response to a combination of a visual and an olfactory predator cue. Subsequently, predator evasion capacity was assessed using a capture test, and swimming endurance was assessed in a flow chamber.