Herring gulls migrate in groups to more temperate climates during the winter, from November to March. The rest of the year, colonies of this species settle near food sources. That’s why it’s not uncommon to see them in urban environments, fields, garbage dumps, and parks, as well as on golf courses, islands, cliffs, and roofs. Perfectly adapted to urban areas, the seagull nests on the roofs of buildings where they are protected from predators. As soon as a colony is well established in a place, it will return there each spring to nest. The seagull can therefore return to nest in the same location for a period ranging from 10 to 20 years.
Omnivorous, the herring gull has the ability to regurgitate food that it can’t digest. Individuals of this species stick together in places where they are likely to recover food scraps left by humans.
Around mid-March, upon returning from their migratory journey, herring gulls find their usual nesting site. In couples, they build a new nest there or improve an existing nest. The female seagull usually has one brood of three eggs per year. Laying takes place around mid-May, and the incubation period usually lasts from 26 to 28 days.