Skip to main content
Dryad logo

Independence of mate choice components (choosiness and preference functions) in Hyla versicolor

Citation

Feagles, Olivia; Hoebel, Gerlinde (2022), Independence of mate choice components (choosiness and preference functions) in Hyla versicolor, Dryad, Dataset, https://doi.org/10.5061/dryad.1c59zw3xp

Abstract

Mate choice is an important cause of natural and sexual selection, driving the evolution of ornaments and promoting diversification and speciation. Mate choice decisions arise from the interaction of several components, and knowledge of whether they interact, and how, is crucial for understanding their contributions to selection. Here we focus on the relationship between preference functions (attractiveness ranking of prospective mates) and choosiness (effort invested in obtaining the preferred mate) and test the hypothesis that they are independent components of mate choice decisions. We examine individual variation in preference functions and choosiness for call duration in female Hyla versicolor treefrogs, and show that measures describing preference functions and choosiness are not correlated. We also found a suggestive but inconclusive pattern that both components are influenced by different factors (body measures and hormones). Independence of preference and choosiness suggests that the joint study of variation in both components is required to gain a complete understanding of how mate choice contributes to sexual selection and speciation.

Methods

There are three different csv files associated with one another: 'PFuncData', 'PREDICTION_1', and 'PREDICTION_2'. Also accompanying this data is a readme file.

PFunc Data -- Collected using acoustic single-speaker playback trials with Eastern Gray Treefrogs (Hyla versicolor). We played simulated artificial male calls of varying duration on speakers broadcast to female frogs. Each female was presented 8 different stimuli (pulse numbers=6, 9, 12, 18, 21, 24, 27) during 8 different behavioral trials. A female was given a maximum of 5 minutes to choose a male call (approached speaker within 10cm). Time to choose was recorded, a faster response indicating a more attractive stimulus. 

Recorded on this data sheet is (1) female ID in columns A and J, (2) the latency to choose (sec) the speaker in columns B-I, and (3) latency to choose subtracted from 5min in columns K-R. Data was transformed (K-R) for input into the program PFunc (https://github.com/joccalor/pfunc) for a more intuitive interpretation.

PREDICTION 1 -- This data is partially derived from the raw data (methods described above) in the 'PFunc' file, the preference function traits. This data was uploaded into the program PFunc (https://github.com/joccalor/pfunc) to gather four different measures on this csv file: Peak (C), Tolerance (D), Strength (E), and Responsiveness (F). Also included are year of collection (A) and female ID (B). Peak indicates the most attractive stimulus, and the other traits generally explain how the preference function deviates from the peak. 

We also include here a different measure of mate choice, choosiness, that indicates the amount of energy a female is willing to invest for the most attractive mate. Although we still use playbacks with artificial male call stimuli, we use a two speaker design with only two stimuli (6 pulse and 18 pulse) played at different amplitudes. By manipulating amplitude, we change the percieved distance from the call, so a quieter call=further away. The choosiness data here indicates the maximum amplitude difference between stimuli (the quietest dB in which the attractive stimulus was chosen).

PREDICTION 2 -- This file examines the relationships between possible influencing variables and the mate choice traits explained above. These include (B) body size, snout-vent-length, (C) condition, regression between mass and SVL, (D) clutch size, (F) testosterone, (G) corticosterone, and the mate choice measures (H-L). Hormone concentrations were measured using ELIZA assays on salivary samples and clutch size was counted using photos and ImageJ (subset of photos uploaded here).

Usage Notes

Uploaded ReadMe file with more detailed explanations of the three csv data sheets.

Funding

James and Dorathea Levenson Ecology and Field Biology Fellowship, Award: 4500

Animal Behavior Society, Award: 2000

Society for the Study of Amphibians and Reptiles, Award: 500