An elongated, tubular bird feeder comprising one or more pairs of interlocking feeder ports, where the feeder ports are of identical constructions, such that each feeder port mates with an identical feeder port. Each port defines an external perch and an external shield that is curved to fit the contour of the tube, a neck which fits tightly into an opening in the tube, and a reduced diameter portion that defines an end face, from which projects two interlocking features: a horizontally-oriented blade member; and a vertically-oriented generally sector-shaped member. When two ports are pushed together into diametrically-opposed side openings in the tube, with end faces located proximate one another, the two sector members will be located adjacent one another to define an essentially semi-circular upper region, and the two blades will be located next to one another to define an essentially horizontal blade member.