Black-headed gulls maybe seen along the coast or inland. Flocks forage along river sides and across farmland. They may be seen following the plough finding worms, grubs and invertebrates. They will snatch insects on the air, or catch small fish from fresh or salt water.

In summer the adult breeding birds have dark heads. Nesting colonies can number anything from two pairs to several hundred.

In winter many move in land to exploit feeding areas and roost reservoirs. The numbers may be boosted at Montrose by North European birds that have migrated south west in the autumn.