Climate change alters sexual signaling in a desert-adapted frog
Calabrese, Gina; Pfennig, Karin (2022), Climate change alters sexual signaling in a desert-adapted frog, Dryad, Dataset, https://doi.org/10.5061/dryad.0k6djhb1z
Climate change is altering species’ habitats, phenology, and behavior. Although sexual behaviors impact population persistence and fitness, climate change’s effects on sexual signals are understudied. Climate change can directly alter temperature-dependent sexual signals, cause changes in body size or condition that affect signal production, or alter the selective landscape of sexual signals. We tested whether temperature-dependent mating calls of Mexican spadefoot toads (Spea multiplicata) had changed in concert with climate in the Southwestern U.S.A. across 22 years. We document increasing air temperatures, decreasing rainfall, and changing seasonal patterns of temperature and rainfall in the spadefoots’ habitat. Despite increasing air temperatures, spadefoots’ ephemeral breeding ponds have been getting colder at most elevations, and male calls have been slowing as a result. However, temperature-standardized call characters have become faster and male condition has increased, possibly due to changes in the selective environment. Thus, climate change might generate rapid, complex changes in sexual signals with important evolutionary consequences.
Climate data were ordered from NOAA GHCND (National Oceanic and Atmospheric Administration, Global Historical Climatology Network Daily) via the Climate Data Online search tool (https://www.ncdc.noaa.gov/cdo-web/search?datasetid=GHCND). These data are in "weatherdata.csv". Processing steps are included and described in the script "weather-data-analysis.R" and also described in the Manuscript, and include quality checks and pruning data columns, weather stations and dates that were not of interest to the study.
Frog calls and breeding pond temperatures were recorded in the field as described in the manuscript (see Methods and also Supplemental Methods). Calls were processed via Audacity and RavenPro software to measure call characters (e.g. call duration, call rate, etc.) as described in the manuscript. Temperature-standardized metrics of each call character were calculated as described in the manuscript. These processed data are in "multiplicata-calls-with-temp-corrections.csv" and the analyses that use this data are in the script "call-rates-over-time-analysis.R". Some examples of original call recordings used in the dataset are provided as supplemental files.
Use "weather-data-analysis.R" in R version 3.6.1 to analyze "weatherdata.csv"
Use "call-rates-over-time-analysis.R" in R version 3.6.1 to analyze "multiplicata-calls-with-temp-corrections.csv"
National Science Foundation, Award: IOS 1555520
Sigma Xia, Award: G201603152056018
Sigma Xia, Award: G2017100191928932
Southwestern Association of Naturalists, Award: Howard McCarley Student Research Fellowship
American Museum of Natural History, Award: Theodore Roosevelt Memorial Fund Grant in Herpetology
American Museum of Natural History, Award: Southwestern Research Station Student Support Fund
Chiricahua Desert Museum, Award: Charles W. Painter Grant in Herpetology
Graduate School, University of North Carolina at Chapel Hill, Award: Summer Research Fellowship