Grey mouse lemurs use 'voice recognition' to avoid incest

This 'voice-recognition' was thought to occur only in large-brained animals with complex social groups, but researchers from Arizona State University and the University of Veterinary Medicine Hannover in Germany found that a tiny, solitary primate is able to recognise paternal relatives via their calls.

The study found that the grey mouse lemur (Microcebus murinus) - a small-brained, solitary foraging mammal endemic to Madagascar - can recognise paternal relatives via vocalisations, thus providing evidence that this is not dependent upon having a large brain and a high social complexity, as previously suggested.

Since grey mouse lemurs are nocturnal solitary-foragers living in dense forests, vocal communication is important for regulating social interactions across distances where visibility is poor and communication via smell is limited.

It is a particularly interesting species with which to study vocal paternal recognition because, in the wild, females remain in the same area of birth and cooperatively raise young with other female kin.

Males do not co-nest with their mates or young and provide no paternal care, which limits opportunities for familiarity-based social interactions. Thus, vocalisations are likely to be important - particularly for avoiding inbreeding.

Researchers found that two of the most frequent calls of the mouse lemur were the mate advertisement call and the alarm call. Using multi-parametric analyses of the call's acoustic parameters, they could see that both call types contained individual signatures.

Through this, they discovered that only male grey mouse lemur advertisement calls, but not alarm calls, contained acoustic paternal signatures. Furthermore, females paid more attention to advertisement calls from unrelated males than from their fathers.

The findings from the study suggest that the discrimination between mate advertisement calls and alarm calls may be an important mechanism for inbreeding avoidance.

This is likely to be highly important in the grey mouse lemur species because males are likely to remain in an area for several years and they can expand their ranges to more than twice that of the female's range, making it likely that adult males' ranges will overlap with those of their daughters from previous mating seasons.

"Given that more complex forms of sociality with cohesive foraging groups are thought to have evolved from an ancestral solitary forager much like the mouse lemur, this suggests that the mechanisms for kin recognition like those seen here may be the foundation from which more complex forms of kin-based sociality evolved," lead author Sharon E Kessler said in a statement.