Abstract: A multi-purpose, species-discriminating bird feeder includes a base, a top, and a plurality of sides extending between the base and the top. At least two of the sides include an upper side member and a lower side member. The upper and lower side members are at least partially spaced from each other to provide an ingress/egress opening so that birds of a selected size may enter and exit an interior portion of the bird feeder through its sides. Birds or mammals larger than the selected size are prevented from entering the interior portion. Each upper side member is manually selectively adjustable so that a size of the respective ingress/egress opening between the upper and lower side members may be adjusted. The construction of the bird feeder provides good visibility for the birds to enter the bird feeder and for bird watchers to watch the birds feed. In addition, the location of the ingress/egress openings allows prompt exit from the feeder by birds disturbed by predators or other disturbance.

Abstract: A convertible bird box as illustrated has upper and lower entrance openings located in a pivoting front wall panel to create an upper roosting perch and a lower nesting location. A closure having a single opening rotates between the upper and lower entrance openings to selectively create a nesting box and a roosting box. The invention further describes a method for selectively forming a winter roosting box and a spring nesting box.