Behavioral dataset for GLMM models testing premating isolation and calculating strength of reproductive isolation in the biguttulus complex

Abstract

The dataset comes from no-choice mating experiments on three closely related grasshopper species of the *Chorthippus biguttulus *complex: C. biguttulus (Big), C. brunneus **(Bru) and C. mollis (Mol). The aim was to measure how male and female courtship behaviors differ between conspecific and heterospecific pairings, and how much each behavior contributes to behavioral reproductive isolation. Adults were either reared under common-garden conditions from field-collected parents or collected directly from the field and acclimated to the lab. Individuals of the same species, sex and origin (lab-reared or wild-caught) were housed in groups of three. Each female was paired individually with a male of each of the three species on three consecutive days. The male species rotated daily, so each female met one conspecific and two heterospecific males. Each trial ran for a maximum of 90 minutes or until mating occurred, with the male species’ song played in the background to stimulate duetting. For each trial, six behaviors were recorded in courtship order: male call singing, male courtship singing, female response (stridulation), male mounting attempt, female rejection, and mating (yes/no). Files and variables File: DataClean.csv is semicolon-delimited, with one row per no-choice trial (one female paired with one male). Counts are unitless event counts per trial. Missing values are coded as NA. Variables Trial_ID: Unique row/trial identifier Trial: Experimental block (a set of parallel female/male group pairings run over three consecutive days). Day: Day on which the trial was run, counted from the start of the experimental series. Day.planned: Day originally scheduled for the trial; may differ from Day if trials were rescheduled. Start: Trial start time, 24-hour clock in hhmm format (e.g., 1500 = 15:00). End: Trial end time, same format as Start. Female: Species of the female: Big (C. biguttulus), Bru (C. brunneus), Mol (C. mollis). Male: Species of the male, same codes. Interaction: Homo (conspecific pair) or Hetero (heterospecific pair). Combination: Female species followed by male species (e.g., BigMol = Big female with Mol male). Type.F: Origin of the female: lab (common-garden reared) or wild (field-collected). Type.M: Origin of the male, same codes. Replicate: Replicate/row number of the trial. Cage.females: ID of the cage (group of three females) the female came from. Used as the grouping variable in the models. Cage.males: ID of the cage (group of three males) the male came from. Box: Number (1-3) of the enclosure in which the pair was tested; three trials ran in parallel. Mating: Whether copulation occurred (1 = yes, 0 = no). Singing: Number of male call songs, sung at a distance from the female (male call singing). Active.Singing: Number of male courtship songs, sung near the female (male courtship singing). Total.Singing: Total number of male songs (Singing + Active.Singing); the denominator for female response. Response: Number of times the female stridulated in response to male song (female response). Hfailed: Number of mounting attempts that failed (male fell off or moved away). Hmount: Number of mounting attempts that were not rejected or failed (i.e., led to copulation). Hrejection: Number of mounting attempts rejected by the female (female kicked the male off), given the number of times a male tried to mount the female. Harassment: Total number of male mounting attempts (male mounting attempt); the denominator for female rejection. Rejection: Number of mounting attempts rejected by the female (female kicked the male off). Total.Rejection: Sum of Hrejection and Rejection Code/software R version 4.4.1, R Core Team, 2024