DOI: 10.5061/dryad.1c59zw46j
title: Data and code from: Microscale temperatures affect the incidence and implications of predator-avoidance behavior in monarch caterpillars

description: The non-consumptive effects associated with the predator-avoidance
 behaviors of potential prey species may commonly be context-dependent. In
 this study, we examined how temperature differences between the plant
 surface and the ground change the consequences of predator-avoidance
 dropping behavior in monarch caterpillars. We hypothesized that these
 temperature differences change on both diel and seasonal timescales, and
 that the risk associated with exposure to potentially high ground
 temperatures is likely to be greater for smaller caterpillars that have
 less thermal inertia and movement ability. We conducted field experiments
 to assess the mortality risk associated with dropping to the ground for
 different-sized caterpillars at a wide range of ground temperatures and to
 assess whether caterpillars show a willingness to drop that is consistent
 with their actual survival probability. We found that the survivorship
 consequences of dropping depend on both temperature and caterpillar size
 and that monarch caterpillars show context-dependent predator-avoidance
 behaviors consistent with adaptive expectations across a wide range of
 temperatures and body sizes. However, we also observed a potentially
 non-adaptive willingness to drop at high temperatures, consistent with a
 biological constraint imposed by increased reactivity. These results
 contribute to a general knowledge gap regarding the context dependence of
 non-consumptive effects in nature.
description: These data were collected as part of a field study. See the
 associated manuscript for more details.
description: # Data and code from: Microscale temperatures affect the incidence and
 implications of predator-avoidance behavior in monarch caterpillars
 [https://doi.org/10.5061/dryad.1c59zw46j](https://doi.org/10.5061/dryad.1c59zw46j) ### Description of the data and file structure We conducted field experiments to assess the mortality risk associated with dropping to the ground for different-sized caterpillars at a wide range of ground temperatures and to assess whether caterpillars show a willingness to drop that is consistent with their actual survival probability. ### Files and variables **File:** Caterpillar_Drop_Project_-_cost_of_drop.csv **Description:** Dataset for the *Drop-survival experiment*. **Variables** * date: date in %m-%d-%Y format * time: time in %I:%M %p format * instar: larval instar, 1-5 * size.mm: length in mm * ground.temp.land.C: temperature of the ground in degrees Celsius * drop.height.cm: initial height in centimeters * land.dist.cm: distance from landing point to the base of the initial host plant in centimeters * obs.time.min: observation time in minutes * fate: text description of observed outcome * success: 1 = survival, 0=mortality **File:** Caterpillar_Drop_Project_-_drop_tests.csv **Description:** dataset for the *Willingness-to-drop experiment* and *Microhabitat selection experiment* **Variables** * date: date in %m-%d-%Y format * time: time in %I:%M %p format * instar: larval instar, 1-5 * size.mm: length in mm * cat.sun: was the caterpillar in the sun or shade at the end of the 20-minute acclimation/habitat selection period? * cat.position: text description of caterpillar location at the end of the 20-minute acclimation/habitat selection period * cat.temp: caterpillar temperature in degrees Celsius * drop: did the caterpillar drop? * air.temp: air temperature in degrees Celsius * ground.temp.shade: shaded ground temperature in degrees Celsius * ground.temp.sun: direct sun ground temperature in degrees Celsius * plant.temp.shade: shaded plant temperature in degrees Celsius * plant.temp.sun: direct sun plant temperature in degrees Celsius ### Code/software **File:** Caterpillar_Drop_Project_Analysis_2025-09-04.Rmd **Description:** Rmarkdown script to analyze data and generate figures. This script was developed with R version 4.4.2 and RStudio 2024.12.0 Build 467 ### Access information none