Data from: Banded mongooses avoid inbreeding when mating with members of the same natal group

Inbreeding and inbreeding avoidance are key factors in the evolution of
animal societies, influencing dispersal and reproductive strategies which
can affect relatedness structure and helping behaviours. In cooperative
breeding systems, individuals typically avoid inbreeding through
reproductive restraint and/or dispersing to breed outside their natal
group. However, where groups contain multiple potential mates of varying
relatedness, strategies of kin recognition and mate choice may be
favoured. Here, we investigate male mate choice and female control of
paternity in the banded mongoose (Mungos mungo), a cooperatively breeding
mammal where both sexes are often philopatric and mating between relatives
is known to occur. We find evidence suggestive of inbreeding depression in
banded mongooses, indicating a benefit to avoiding breeding with
relatives. Successfully breeding pairs were less related than expected
under random mating, which appeared to be driven by both male choice and
female control of paternity. Male banded mongooses actively guard females
to gain access to mating opportunities, and this guarding behaviour is
preferentially directed towards less closely related females. Guard–female
relatedness did not affect the guard's probability of gaining
reproductive success. However, where mate-guards are unsuccessful, they
lose paternity to males that are less related to the females than
themselves. Together, our results suggest that both sexes of banded
mongoose use kin discrimination to avoid inbreeding. Although this
strategy appears to be rare among cooperative breeders, it may be more
prominent in species where relatedness to potential mates is variable,
and/or where opportunities for dispersal and mating outside of the group
are limited.