DOI: 10.5061/dryad.zcrjdfnk3
title: Data for: Multiple mechanisms for inbreeding avoidance used simultaneously in a wild ape

description: Mating with close kin can have considerable negative fitness consequences,
 which are expected to result in selective pressure for inbreeding
 avoidance mechanisms, such as dispersal, mate choice and postcopulatory
 biases. Captive studies have suggested that inbreeding avoidance through
 mate choice is far less widespread than expected and may be absent where
 other mechanisms already limit inbreeding. However, few studies have
 examined multiple mechanisms of inbreeding avoidance simultaneously,
 particularly in the wild. We use 13 years of detailed dispersal,
 copulation, and paternity data from mountain gorillas to examine
 inbreeding avoidance. We find that partial dispersal of both sexes results
 in high kinship in multimale groups, but that copulations between close
 kin occur 40% less than expected. We find strong kin discrimination in
 mate choice, with significant avoidance of maternal kin but more limited
 avoidance of paternal kin. We find no evidence for post-copulatory
 inbreeding avoidance. Our analyses support familiarity-based mechanisms of
 kin identification and age-based avoidance that limits mating between
 fathers and daughters in their natal group. Our findings demonstrate that
 multiple complementary mechanisms for inbreeding avoidance can evolve in a
 single species and suggest that inbreeding avoidance through mate choice
 may enable more flexible dispersal systems to evolve.
description: # Data for: Multiple mechanisms for inbreeding avoidance used
 simultaneously in a wild ape
 [https://doi.org/10.5061/dryad.zcrjdfnk3](https://doi.org/10.5061/dryad.zcrjdfnk3) **Copulation data:** Between 2003 and 2015, the Fossey Fund monitored between 3 and 12 gorilla groups for up to 4 hours each day. During monitoring, copulations were recorded both *ad libitum* (i.e., whenever observed) and as part of the focal follow protocol. In each year, in each multimale group, we extracted copulations that were observed between opposite-sex pairs in which the female was over the age of 6 years (n=71) and the male was over the age of 9 years (n=52) by the start of the year, and both individuals were present in the same group for the entire year. We extracted the total number of copulations observed between the pair during the year. The number of hours of *ad libitum* and focal observation for each pair in each year was also calculated. Groups with fewer than 700 hours of observation in a year were excluded. Kin relationships between each dyad were inferred based on the mother and father of each individual: mother-son (n=82), father-daughter (n=93), maternal siblings (n=60), paternal siblings (n=301), full siblings (n=27), none (n=685) and unknown (n=1101). **Paternity bias data:** All offspring of known paternity born within the study population, with estimated dates of conception between 2003 and 2015 were extracted from the demographic data (n=44). All the mother’s copulations in the 1-month on either side, and the 6-months on either side of the estimated conception date were extracted, and the kinship of the mating partners identified. These data were summarised into the number of copulations, and number of mating partners in each of the kin categories ## Description of the data and file structure **Copulation data:** Each line represents one co-resident opposite-sex pair of mountain gorillas of reproductive age, in one year. Rows include female and male ID, the number of times they were observed copulating, the group and year, the number of hours the group was monitored for that year, the number of hours the female was followed as a focal individual that year, the number of hours the male was followed as a focal individual that year, whether the female had an offspring under 3 years old, the kinship category of the pair, whether they were maternal kin, whether they grew up in the same natal group, their estimated genetic relatedness, the female's age (years), whether the female was in her natal group, and the male's age (years). **Paternity bias data:** Each line represents an infant of known paternity born within the study population with an estimated date of conception between 2003 and 2015. Columns indicate the group they were born in, their ID, the ID of their mother and father, their estimated date of conception, the kin category of their parents, and the number of copulations involving their mother that were observed in the one month and six months either side of their conception, and the number of mating partners the mother had, in each of the kin categories.