The Pied Avocet breeds in colonies on open coastal meadows and low, sparsely vegetated islands. The nest is a simple scrape on the ground, sometimes with a little nest material, and the clutch usually comprises 3–4 eggs. Colonial breeding gives protection against predators, and the birds jointly and aggressively defend their nests and young by launching repeated mock attacks at intruders. When disturbed, the whole colony leaves the nests at once and meets the intruder with a concerted, loud defence, which effectively drives off many predators.