Just two of Sydney’s sulphur-crested cockatoos spread the word to all its mates (and theirs).
An innovation discovered or introduced at a few nodes can diffuse through overlapping local relationships until it becomes population-level culture. The network also preserves useful behaviour beyond the individuals that first acquired it, suggesting a natural model for decentralised learning in which capability belongs partly to the connectivity of the collective rather than solely to individual agents.
Researchers individually track birds and their relationships while testing how novel behaviours spread. In one experiment, just two cockatoos were taught to accept brightly coloured almonds; within ten days, birds as far as ten kilometres away were eating them. Evidence indicated that the behaviour travelled predominantly through imitation along social connections. Similar social transmission underlies difficult urban skills such as opening municipal bins and operating drinking fountains.
