Researchers analyzing parrot social networks reveal a sophisticated structure of ever-shifting alliances and competitors, behaviors that have only been well-studied in primates and other mammals. Their advanced cognition allows them to live in complex, dynamic social environments, according to a new study published in The Auk: Ornithological Advances.
Brainy mammals such as dolphins and primates, as well as social carnivores like hyenas and lions, have well-documented complex social behaviors. What differentiates many of them from big populations of cooperating critters, like ants and bees, is their dynamic setting with layers of relationships and complex interactions. Parrots have unusually large brains relative to their body size, yet assumptions about parrot sociality have remain largely untested.
So, to quantify the social lives of parrots, a trio of researchers led by Elizabeth Hobson from New Mexico State University observed wild monk parakeets (Myiopsitta monachus) in Argentina and captive ones in Florida. They wanted to test several common assumptions about pair bonds, dominance hierarchies, and the changing composition of social groups.
Because parrots in the wild are often seen flying in pairs, researchers assumed that parrot sociality revolves around the pair bond. And their analyses reveal that parrots in captive groups at least do show a strong preference for associating with a specific individual and are usually found near their mate. They're not flying around with just any individual. Supported pairs are the fundamental unit of parakeet social structure, although these close associates weren’t always heterosexual breeding pairs and were sometimes even trios.
The team also found evidence for ancillary tiers of social structure. These networks are highly connected with very strong associations between one or two other individuals, multiple moderate associates, and a few weak associates. Although, the researchers found no evidence that they share foraging information among groups.
In addition to these positive social ties, there were also negative social relationships marked by aggression. The researchers were able to use their observations of winners and losers in aggressive encounters to assign individual parakeets a dominance rank.
Taken together, the findings show that the social lives of monk parakeets are structured by several types of relationships. For individuals to recognize where they fit in, they’d need to recognize and remember others in their group, remember how they interacted with specific individuals previously, and remember the outcomes of those interactions. Having to manage this process would require significant cognitive skills.
"Understanding the social systems of parrots is critical to understanding social processes, such as vocal learning and the spread of behaviors,” Hobson says in a news release, “and can also give us greater insight into how social and cognitive complexity evolved in other species.”