Ontogenetic modulation of risk perception and decision making in larval anurans
Data files
Abstract
To select cost-effective defensive responses, prey need to fine-tune defensive responses by integrating reliable information about predation risk with their own physiological state and energetic needs. While it is difficult to assess the actual perceived level of risk, we hypothesized that stage-related variation in defensive responses to different predation cue concentrations may offer valuable insight into decision making under predation risk. To test this hypothesis, we examined Italian agile frog (Rana latastei) tadpoles’ sensitivity to both fed and fasted predator cues at varying concentrations (1:1, 1:10, 1:100, 1:500) and two developmental stages (26-28 and 30-31 Gosner stages). Younger tadpoles responded similarly to both types of cues, by markedly lowering activity levels when exposed at 1:1 and 1:10 cues, while no significant difference from the control was recorded at low cue concentrations. Older tadpoles in contrast, showed heightened sensitivity to fed predator cues, responding even at 1:100, while largely ignoring cues from fasted predators. These results highlight a developmental shift in risk assessment, consistent with changing trade-offs between predator avoidance and other life-history priorities. This shift suggests that ontogenetic changes shape not only the strength but also the selectivity of perceived risk, reflecting more nuanced decision-making as developmental priorities evolve.
Overview
This dataset contains behavioural measurements of larval amphibians (Rana latastei) used to investigate how developmental stage modulates antipredator responses to predator chemical cues. The experiment tested the combined effects of predator diet, cue concentration, and ontogeny on activity and movement. The data support the findings reported in the manuscript Ontogenetic Modulation of Risk Perception and Decision Making in Larval Anurans.
Files and Variables
Data file
data.txt: Tab-delimited text file containing all behavioral data.
Variables
id: Unique identifier for each individual tadpole.date: Date of the video recording.session: Developmental stage (1 = one week post-hatching; 2 = three weeks post-hatching).cod_video: Identifier of the video file.tub: Identifier of the tub within the experimental arena.clutch: Identifier of the clutch from which the tadpole originated.stimulus: Predator chemical cue type and concentration (fed or unfed at 1:1, 1:10, 1:100, or 1:500 dilution).tot.time_frozen_s: Total time (in seconds) the tadpole remained inactive during the pre-stimulus period.tot.time_frozen_s_post: Total time inactive (in seconds) during the post-stimulus period.total_distance: Distance covered (in millimetres) during the pre-stimulus period.total_distance_post: Distance covered (in millimetres) during the post-stimulus period.
Data collection
-Experiments were conducted in indoor laboratory conditions in northern Italy between March and April 2023. Each individual was filmed once during a -36-minute trial comprising pre- and post-stimulus phases.
Code and Analysis
Script
Script.R: R script used for all statistical analyses, including data import, preprocessing, model fitting (GLMM and Bayesian models), and visualization of results.
Software
Analyses were conducted in R (version 4.3.2) using the following packages:
glmmTMB,brms,DHARMa,emmeans,ggplot2, and others (see script header for details).
Notes
- This dataset and code are provided to ensure full reproducibility of all analyses and figures reported in the manuscript.