7-10-2024 RIVER SHANNON, LIMERICK - BLACK HEADED GULL (Chroicocephalus ridibundus)

The Black-headed gull (Chroicocephalus ridibundus) is a small and one of the most abundant gulls in much of Europe and Asia, and also in eastern Canada. It displays a variety of compelling behaviors and adaptations. Some of these include removing eggshells from one's nest after hatching, begging co-ordination between siblings, differences between sexes, conspecific brood parasitism, and extra-pair paternity.

The summer adult has a chocolate-brown head (not black, although does look black from a distance), a pale grey body, black tips to the primary wing feathers, and a red bill and legs. The hood is lost in winter, leaving just two dark spots. Immature birds have a mottled pattern of brown spots over most of the body and a black band on the tail. There is no difference in plumage between the sexes. In flight, the white leading edge to the wing is a good field mark. First-year birds have a black terminal tail band, more dark areas in the wings, and, in summer, a less fully developed dark hood.