THE black-headed gull (Chroicocephalus ridibundus) is a small bird, measuring approximately 40 centimeters in length and weighing around 250 grams. It has a white body and wings, with a black hood that is prominent during the breeding season but absent during migration, revealing a white head. The bill is red with a black tip, and the legs are greenish-yellow. During the winter months, these fascinating birds stop in Shenzhen on their migration route. They inhabit various habitats such as wetlands, lakes, rivers, and coastal areas. In our city, Shenzhen Bay Park is the most likely location for spotting them. In the breeding season, they form large colonies near water bodies, while atother times, they gather in smaller groups along coastlines. These social birds often assemble in sizable flocks and are recognized for their vocal nature. They have a diverse repertoire of calls, including a distinctive “l(fā)aughing” call. They exhibit impressive aerial acrobatics when hunting for insects and small fish. Black-headed gulls primarily feed on insects, small fish, crustaceans, mollusks, carrion, and refuse, which explains their regular presence in urban areas. During the breeding season, they also consume earthworms and aquatic insects. They build nests on the ground, typically among vegetation or on islands. The female lays up to three eggs per clutch, which will hatch after about three weeks. Both parents take turns incubating the eggs and caring for the young. The chicks fledge after about four weeks and become independent after another four. Despite its substantial population and wide distribution, the black-headed gull faces threats from habitat loss and pollution, especially in urban areas. Conservation efforts aim to protect and restore wetland habitats, reduce pollution, and promote sustainable fishing practices. | 