Yes, as a matter of fact....we have seen seagull babies. The nests we have seen are in South Boston, MA, on warehouse roofs along the Boston Harbor. We go there twice weekly to pick up seafood . The chicks get large (looking bigger than mom) quickly, but are tan and brown instead of black, white, and grey. The nests are generally close to obstructions sticking up from the roof that help hold them in place.