A poultry feeder is provided which can be selectively switched between a mode in which it operates as a flood-type feeder and a mode in which it operates as a shallow-fill type feeder with adjustable height pan walls. The feeder includes a feed tube assembly comprising a drop tube and a feed flooding tube. The drop tube is movable axially relative to the feed flooding tube, which rests on the feed pan. The drop tube and feed flooding tube have windows which are brought into and out of alignment by raising and lowering the drop tube. When the feed flooding tube window is opened, the feeder operates in a flood mode and when the feed flooding tube is closed, the feeder operates in a shallow-fill mode. In this second mode, the effective height of the pan wall can be adjusted to allow chicks and chickens access to the feed.