DOI: 10.5061/dryad.k3j9kd5hq
title: Homophily in social and demographic traits predict association patterns in female western and mountain gorillas

description: Affiliative relationships are a hallmark of social relationships in
 gregarious mammals, but what drives variation of association patterns
 remain to be investigated. Gorillas, who exhibit female dispersal, provide
 an interesting counterpoint to female philopatric species to examine the
 factors influencing variation in association patterns. We examined
 demographic and social factors that may predict association patterns of
 female western (Gorilla gorilla gorilla; Loango, Gabon) and mountain
 gorillas (Gorilla beringei beringei; Bwindi, Uganda). We looked at dyadic
 and individual strength scores of social proximity data (37 group-years).
 For individual female gorillas, high dominance rank increased association
 scores and being newly emigrated decreased them. For dyads, higher mean
 dominance rank, and both partners having a dependant infant increased
 association scores, whereas a partner being newly emigrated decreased
 association scores. Further analysis of time-matched birth and emigration
 events confirmed the temporal nature of these associations. Overall,
 female gorilla association patterns show flexibility in association
 strength based on real time contingencies, namely social and demographic
 traits. Our results suggest that affiliative relationships in species with
 female secondary dispersal are governed by homophily like that of modern
 humans. Understanding the female gorilla social structure can enhance our
 knowledge of the evolutionary origins of sociality.
description: This data relates to data collected on mountain and western
 gorilla females association patterns and the predictor variables.
 Continuous variables have been z-transformed. Please refer to the
 manuscript for full details of the methods. 
description: # Homophily in social and demographic traits predict association patterns
 in female western and mountain gorillas
 [https://doi.org/10.5061/dryad.k3j9kd5hq](https://doi.org/10.5061/dryad.k3j9kd5hq) ## Description of the data and file structure Files are stored as .csv files. There are 4 files in total each referring to models 1-4 of the analysis.  ### Files and variables #### File: Model4.csv **Description:** Data to run the time-matched analysis for female gorilla dyadic immigration status - model 4. ##### Variables * Group: Gorilla group ID - ATA, KYA, ORU, BIT. * ID: Female gorilla ID - first dyad member. * ID2: Female gorilla ID - second dyad member. * Strength: Association strength score: the number of times both individuals were within 5m of each other divided by the total number of scans that each was the focal animal. * year: Year of data collection. * Event: Was the dyad one where one dyad member was an immigrant female Y =  Yes, N = No. * TimePeriod: Time period of data collection in years related to the immigration event: 0 = year of immigration, 1, 2, 3 ,4  = 1, 2, 3, 4 years after the event. * DyadID1: Female dyad ID. #### File: Model3.csv **Description:** Data to run the time-matched analysis for female gorilla dyadic birth status - model 3. ##### Variables * Group: Gorilla group ID - ATA, KYA, ORU, BIT. * ID: Female gorilla ID - first dyad member. * ID2: Female gorilla ID - second dyad member. * Strength: Association strength score: the number of times both individuals were within 5m of each other divided by the total number of scans that each was the focal animal. * year: Year of data collection. - TimePeriod:Time period of data collection in years related to the birth event: 0 = year of birth, -2,-1, 1, 2, = -2, -1, 1, 2, years before or after the event. - Event: Was the dyad one where both dyad member had a dependant infant Y =  Both, N = None/One. - DyadID1: Female dyad ID. #### File: Model1.csv **Description:** Data to run the individual level analysis for predictors of female gorilla association scores- model 1. ##### Variables * Group: Gorilla group ID - ATA, KYA, ORU, BIT. * ID: Female gorilla ID. * Strength: Association strength score: the total number of times each individual was observed within a 5m radius of another female group member per year, controlling for the total number of scans collected per female. * Year: Year of data collection. * Infant: Did the female have an infant that year - yes/no. * Immigrant: Was the female a new immigrant that year - yes/no. * last.year: Was it the females last year in the group - yes/no. * Tenure: Z-transformed female residency length in days. * OrdRank: Z-transformed females ordinal rank position. * ZGrpS: Z-transformed group size. * SBChange: Was there a new alpha male that year - yes/no. * ZFem: Z-transformed female number. #### File: Model2.csv **Description:** Data to run the dyadic level analysis for predictors of female gorilla association scores- model 2. ##### Variables * Group: Gorilla group ID - ATA, KYA, ORU, BIT. * ID: Female gorilla ID - first dyad member. * ID2: Female gorilla ID - second dyad member. * Strength: Association strength score: the number of times both individuals were within 5m of each other divided by the total number of scans that each was the focal animal. * Year: Year of data collection. * Dyad_ID: Female dyad ID. * SB_New: Was there a new alpha male that year - yes/no. * Infant1: Did one, both or neither female dyad member have an infant - both/one/none. * New_Dyad: Was one female dyad mamber new to the group that year - yes/no. * ZGp: Z-transformed group size. * ZFemNum: Z-transformed female number. * ZRankAve: Z-transformed average dominance rank for each dyad. ## Code/software Data are in .csv files so can be accessed via any programme to open .csv files e.g., excel or numbers. The R markdown file contains 4 sections to run the four models. The code to run the analysis was done in R (version 4.3.1).  Packages used for each analysis are listed with in the R markdown file ## Access information Other publicly accessible locations of the data: * No publicly accessible locations. Data was derived from the following sources: * Data was not derived from any other sources.