Author contact information:
Megan K. Freiler, University of Minnesota (freil018@umn.edu)
Liam N. Halstead, Swarthmore College (lhalste1@swarthmore.edu)
Mark A. Bee, University of Minnesota (mbee@umn.edu)
Alexander T. Baugh, Swarthmore College (abaugh1@swarthmore.edu)

Last updated: 3/22/2025

Description: Data on steroid hormone levels and morphological measures of Cope's gray treefrogs in an experimentally induced amplexus experiment.

During amplexus, male frogs clasp a female for several hour prior to gamete release. In this experiment, we tested the hypothesis that amplexus can cause changes in circulating levels of steroid hormones in Cope's gray tree frogs ('Hyla chrysoscelis'). Frogs were collected in breeding ponds in Carver Park Reserve in Minnesota in May and June of 2024. An amplexed pair and two single males were collected in quick succession and brought to the edge of the pond for each experimental trial. In each trial, we quantified levels of testosterone, estradiol, and corticosterone after 90 minutes in four treatment groups: males allowed to enter amplexus with a newly provided female ("amplexus induced"), paired males removed from their mate ("amplexus terminated"), unpaired control males, and the female that was removed from the amplexus terminated male and given to the amplexus induced male.

amplexushormonedata2024.csv

This file contains data on several steroid hormone levels, morphological measures of frogs, and environmental and time parameters during an induced amplexus experiment.

subjectID = identification code for each individual frog (1-42 a,b,c,f)
trial = alphabetic code to denote the trial 
treatment = letter to denote each experimental treatment group with four levels: a is "amplexus 		terminated", b is "amplexus induced", c is "control", and f is "female".
sex = whether frog was male (m) or female (f)
trial_starttime = time (min after 2200 h) the experimental trial began
amplex_starttime = time (min after 2200h) the amplexus induced group entered amplexus
time_amplex = time (min) it took male b ("amplexus induced") to enter amplexus with the provided female 
svl = snout-vent-length (mm) of the frog
tfl = tibia-fibula-length (mm) of the frog
mass = body mass (g) of the frog
frog_temp = estimated body temperature (°C), taken by measuring the temperature of the water the frogs was in with an infrared thermometer
bleed_starttime = time (min after 2200 h) that whole blood was collected from the subject
time_bleed = time (to nearest min) it took to collect whole blood from the subject
bleed_latencytotal = time (min after 2200 h) whole blood was collected after trial started
bleed_latencyamplex = time (min after 2200 h) whole blood was collected after amplexus induced male entered amplexus
plasma = estimated plasma volume (μL) of sample
testosterone = levels of circulating testosterone (pg/μL) quantified by EIA
corticosterone = levels of circulating corticosterone (pg/μL) quantified by EIA
estradiol = levels of circulating estradiol (pg/μL) quantified by EIA