In the beginning of the summer, brownish-grey nestlings can even be found on the city streets and these nestlings cannot be placed back into the nests which may be located at high roofs.
The nestlings may be from different gull species. See if the nestling has webbed feet (most waterfowl have) and transport the nestling near a water body. Such suitable places are such where people do not go that often and where reed, bulrush or willows, etc. grow. Place the nestling in such a suitable place: it will find food itself and it can hide (from danger) between the plants. Waterfowl are mostly friendly and an individual nestling is adopted by a family with a progeny of the same species.
Make sure that the nestling taken to a new place does not follow you!
