Seagull chicks are speckly and well-camouflaged, and are often difficult to see. Gulls nest colonially, usually on rocks, shingle or similar, but some kinds on flat roofs.
Once fledged, young gulls look different to adults, although they are the same size and shape. Herring gulls and black-backs, for example, are uniform brown the first year, other kinds have strong brown stripes on the wings. Some don't reach breeding age or full adult plumage for four or more years.