DOI: 10.5061/dryad.crjdfn3b3
title: Social environment and masculinization level interact to explain testosterone levels in a communally rearing rodent: part 2: the female side

description: Testosterone is known as a “male” hormone; however, females also
 synthetize testosterone, which influences female sexual and aggressive
 behavior. In female vertebrates, season affects female testosterone levels
 as consequence of adrenal activation during the nursing season, as females
 are undergoing high energetic demands. However, female testosterone levels
 may also be related with female anogenital distance (AGD) phenotype (a
 proxy of prenatal androgen exposition), and the social group environment.
 We used data from a long-term rodent study (2009–2019) in a natural
 population of degus (Octodon degus) to examine the potential associations
 between female serum testosterone levels, season, female AGD phenotype,
 and social group composition. We quantified female serum testosterone
 levels during the mating and offspring rearing seasons, and we determined
 the number of females and males in social groups, as well the composition
 of groups, in terms of the AGD of the female and male group mates. Our
 results indicate that female testosterone levels vary with season, being
 highest during the offspring rearing season. Additionally, female
 testosterone levels were associated with the number of male group-members
 and the AGD of male group-members but were not associated with female
 social environment and focal female AGD phenotype. Together, our results
 suggest that female testosterone levels are sensitive to intersexual
 interactions. Our results also reveal that female and male testosterone
 levels do not differ between the sexes, a finding previously reported only
 in rock hyraxes. We discuss how the complex social system of degus could
 be driving this physiological similarity between the sexes.
description: # SOCIAL ENVIRONMENT AND MASCULINIZATION LEVEL INTERACT TO EXPLAIN
 TESTOSTERONE LEVELS IN A COMMUNALLY REARING RODENT: PART 2: THE FEMALE
 SIDE Data contained in this file correspond to individual and social group
 data from a wild population of degus (*Octodon degus*) and include data
 from two seasons (mating and offspring rearing) and eleven years (from
 2009 to 2019). For model 1, use testosterone data from both sheets (1 and
 2). For model 2, use data from sheet 1. For model 3, use data from sheet
 2. **Results 3.1.** To test the prediction (i) about focal female serum
 testosterone levels vary across reproductive season, run model model 1.
 **Results 3.2.** To test predictions (ii and iii) about that potential
 effects of female AGD phenotype, number of females, and mean group female
 AGD, on female testosterone levels during mating season, run model 2.1. To
 test predictions (ii and iv) about that potential effects of female AGD
 phenotype, number of males, and mean group male AGD, on female
 testosterone levels during mating season, run model 2.2. **Results 3.3.**
 To test predictions (v and vi) about that potential effects of female AGD
 phenotype, number of females, and mean group female AGD, on female
 testosterone levels during offspring rearing season, run model 3.1. To
 test predictions (v and vi) about that potential effects of female AGD
 phenotype, number of males, and mean group male AGD, on female
 testosterone levels during offspirng season, run model 3.2. In all models,
 log-transformed testosterone is the response variable. Season, focal
 female AGD, N of males, N of females, mean group female AGD, and mean
 group male AGD, were fixed factors. Year, Degu ID, were random factors.
 Model 1-2-3 included the year of study and degu identity (Degu ID) as
 random factors. Model fits were assessed with quantile residual
 dispersion. Best models were chosen by their AICc values and average model
 weight. Description of the data and file structure The file contains two
 sheets with data: Sheet 1: mating season data. Sheet 2: offspring rearing
 season data. Data from mating season include data from 2010 to 2019. Data
 from offspring-rearing season include data from 2009 to 2019. Blank cells
 corresponds to cells were data do not exists Variables included: Year
 (individual variable). Degu ID: Ear tag number or degu identity. Some
 individuals are present several times (2-5 times). For these individuals,
 each data must be considered as independent data (individual variable).
 Sex: F= female/M=male (individual variable). Group ID: The number of the
 social group to which the degu belonged. Some females were alone, these
 females should be included in model 1. Model 2 and 3 that include the
 analysis of the n of males and females and mean group males and female AGD
 variables, should be run without data from females that were alone (Social
 group variable). N of females: is the total number of females in each
 social group (Social group variable). N of males: is the total number of
 males in each social group (Social group variable). Focal AGD (mm): is the
 length of the anogenital distance, expressed in millimeters, of the focal
 individuals (individual variable). Mean group female AGD (mm): the mean
 AGD of female group mates, expressed in millimeters (social group
 variable). Mean group male AGD (mm): the mean AGD of male group mates
 after excluding the focal male AGD. Expressed in millimeters (Social group
 variable). Testosterone level (nmol/L): is the measurement of serum
 testosterone, expressed in (nmol/L). As the testosterone variable does not
 have a normal distribution, to work with data, the testosterone variable
 should be transformed by Log (individual variable). Freeform section for
 describing any code in your submission and the software used to run it.
 Analyses were performed in R 4.1.3 (R Core Team 2022). Linear mixed models
 (LMM) were fitted with the package LME4 1.1-31. DHARMa 0.4.6 and MuMIn
 1.46.0 packages were used to perform residual diagnostics and model
 selection routines, respectively.