Open AccessNo evidence for female kin association, indications for extragroup paternity, and sex‐biased dispersal patterns in wild western gorillas
Author(s) -
Masi Shelly,
Austerlitz Frédéric,
Chabaud Chloé,
Lafosse Sophie,
Marchi Nina,
Georges Myriam,
DessarpsFreichey Françoise,
Miglietta Silvia,
SottoMayor Andrea,
Galli Aurore San,
Meulman Ellen,
Pouydebat Emmanuelle,
Krief Sabrina,
Todd Angelique,
Fuh Terence,
Breuer Thomas,
Ségurel Laure
Publication year - 2021
Publication title -
ecology and evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.17
H-Index - 63
ISSN - 2045-7758
DOI - 10.1002/ece3.7596
Subject(s) - biological dispersal , biology , gorilla , polygyny , offspring , kin recognition , zoology , inbreeding avoidance , ecology , kin selection , demography , evolutionary biology , mate choice , population , mating , genetics , pregnancy , paleontology , sociology
Characterizing animal dispersal patterns and the rational behind individuals’ transfer choices is a long‐standing question of interest in evolutionary biology. In wild western gorillas ( Gorilla gorilla ), a one‐male polygynous species, previous genetic findings suggested that, when dispersing, females might favor groups with female kin to promote cooperation, resulting in higher‐than‐expected within‐group female relatedness. The extent of male dispersal remains unclear with studies showing conflicting results. To investigate male and female dispersal patterns and extragroup paternity, we analyzed long‐term field observations, including female spatial proximity data, together with genetic data (10 autosomal microsatellites) on individuals from a unique set of four habituated western gorilla groups, and four additional extragroup males (49 individuals in total). The majority of offspring (25 of 27) were sired by the group male. For two offspring, evidence for extragroup paternity was found. Contrarily to previous findings, adult females were not significantly more related within groups than across groups. Consistently, adult female relatedness within groups did not correlate with their spatial proximity inferred from behavioral data. Adult females were similarly related to adult males from their group than from other groups. Using R ST statistics, we found significant genetic structure and a pattern of isolation by distance, indicating limited dispersal in this species. Comparing relatedness among females and among males revealed that males disperse farer than females, as expected in a polygamous species. Our study on habituated western gorillas shed light on the dispersal dynamics and reproductive behavior of this polygynous species and challenge some of the previous results based on unhabituated groups.