The Complete Handbook of Bird & Wildlife Feeders

Chapter 1: Understanding Bird & Wildlife Feeders

Bird and wildlife feeders are simple mechanical devices, but their simplicity hides a complex set of variables that directly determine their usefulness. At its core, a feeder is a containment and delivery system designed to do one of two things: protect a food supply from weather and pest animals, or present food in a way that is convenient and safe for a specific target species. The engineering that goes into a feeder, from the angle of a seed port to the thickness of a plastic hopper, is there to balance these two goals. A feeder that does not protect the seed from rain merely replaces a bird an hour with a handful of moldy mush. A feeder that cannot exclude a squirrel is, in effect, an expensive squirrel restaurant. Understanding how these systems work is the first step in choosing a product that does its job reliably for years.

To understand how feeders work, it is useful to separate the food management system from the physical structure. The food management system includes the reservoir, the transport mechanism, and the delivery port. A tube feeder holds seed in a vertical cylinder. Gravity pulls the seed down to a series of ports, where a bird removes a seed, allowing the seed above to settle into the empty space. If the port is too small for the seed, the feeder jams. If the port is too large, the seed spills onto the ground, where it is