Most mammals that live in social groups avoid inbreeding in a simple way: They don’t mate with others in their group.
Banded mongooses, however, rarely leave their social groups. Still, they mostly manage to avoid mating with their nearest relatives.
Jenni Sanderson, an ecologist at the University of Exeter in England, and her colleagues tracked the mating behavior of more than 100 mongooses in about 10 different social groups in western Uganda for 16 years. The researchers shaved a unique pattern into the fur of each mongoose for identification purposes.
Only on rare occasions did Dr. Sanderson and her colleagues observe close inbreeding, like a father mating with a daughter. The findings appear in Molecular Ecology.
Inbreeding can result in smaller, less fit offspring, so it makes sense for mongooses to avoid close family members. But exactly how they identify relatives remains a mystery.
“They have individually recognizable voices,” Dr. Sanderson said. “It could be that they know their closest relatives sound most like them.”
They could also be using the sniff test. Mongooses within a social group have similar chemical secretions, Dr. Sanderson said, and it may be that close relations share a similar smell.
A report in the Observatory column on June 16 about the way in which a banded mongoose manages to avoid mating with its nearest relatives misstated part of the name of the journal that published the research. It is Molecular Ecology, not Molecular Biology.