(CNN)Complex societies were thought to only exist among mammals, including humans, other primates, elephants, giraffes and dolphins.
But a new study shows that vulturine guinea fowl, a bird with distinctive blue plumage that lives in Africa, can keep track of relationships with hundreds of others -- challenging the prevailing view that big brains are a requirement for complex society.
While many birds live in groups, these birds behave "highly cohesively" and don't display any aggression between groups.
"To our knowledge, this is the first time a social structure like this has been described for birds," said Danai Papageorgiou, lead author of the paper published Monday in Current Biology and a PhD student at the Max Planck Institute of Animal Behavior in Germany.
"It is remarkable to observe hundreds of birds coming out of a roost and splitting up perfectly into completely stable groups every single day."
The study, which is the first conducted on the species, involved tracking social relationships in a population of more than 400 adult birds in Kenya for 12 months. Tracking the vulturine guinea fowl took place at the Mpala Research Centre and Wildlife Foundat