The black-headed gull (Chroicocephalus ridibundus) is a common, small gull species found across Eurasia. It has primarily white-grey plumage, with breeding individuals displaying a distinctive brown-black head, a feature absent in non-breeding birds. This gull inhabits wetlands, coastal areas, and lake islets, often forming large colonies of hundreds. Its diet is diverse, including invertebrates, fish, seeds, and carrion.