Abstract:
Female intrasexual competition can be intense in cooperatively breeding species, with some
dominant breeders (matriarchs) limiting reproduction in subordinates via aggression, eviction
or infanticide. In males, such tendencies bidirectionally link to testosterone, but in females,
there has been little systematic investigation of androgen-mediated behaviour within and
across generations. In 22 clans of wild meerkats (Suricata suricatta), we show that matriarchs
1) express peak androgen concentrations during late gestation, 2) when displaying peak
feeding competition, dominance behaviour, and evictions, and 3) relative to subordinates,
produce offspring that are more aggressive in early development. Late-gestation antiandrogen
treatment of matriarchs 4) specifically reduces dominance behaviour, is associated with
infrequent evictions, decreases social centrality within the clan, 5) increases aggression in
cohabiting subordinate dams, and 6) reduces offspring aggression. These effects implicate
androgen-mediated aggression in the operation of female sexual selection, and intergenerational
transmission of masculinised phenotypes in the evolution of meerkat cooperative
breeding.
