Avocets are typically gregarious much of the year.
Outside the breeding season the birds are usually in flocks of 6-30 individuals, but feeding flocks in certain conditions can be several hundred strong. Flocks break up for the duration of the breeding season.
Summer flocks consist at first of immature non-breeders, later joined by failed breeders and then adults with fledged young.
The mating behaviour of avocets is very elegant. Initially both birds can be seen preening vigorously, then the female lowers her head, stretches it low over the water and stands almost motionless. The male continues to preen excitedly, frequently dipping his bill in the water and moving first to one side of her and then the other, switching sides many times by walking behind her (if he passes in front copulation is unlikely to take place).
Eventually he jumps sideways onto her back and with wings spread and bill open sinks down onto his tarsi whilst she swings her head from side to side.
After copulation, the male drops sideways into the water and the pair run forward with bills crossed, the male with one wing over the females back. Finally they run away from each other in a hunched posture.