Data from: The role of between-group signalling in the evolution of primate ornamentation

Gregarious mammals interact to varying degrees and in a variety of ways
with neighbouring groups. Since navigating this wider social environment
via conventional means (social knowledge) may be challenging, we
hypothesize that between-group socio-spatial dynamics have exerted strong
selection on phenotypic markers of individual identity, quality and
competitive ability. Ornaments are sexually selected decorative traits
with far-reaching signalling potential. Here, we examined the links
between sexual dimorphism in ornamentation, home range use and encounter
rates across 144 primate species in a Bayesian framework. We show that
home range overlap (shared space among neighbours), an indicator of the
complexity of between-group interactions (but not necessarily male-male
competition), is positively associated with dimorphism in ornamentation.
We find no clear effect for between-group encounter rates. We also find
that inter-group interactions were less agonistic when there was greater
home range overlap. Taken together, these findings indicate that ornaments
play a hitherto underappreciated role in signalling to conspecifics
outside the realms of their home groups.