won't protect useful objects, so we don't think that would be the best choice (unless you want to stop others from copying your bird feeder's imagery). Instead, consider one of the following methods of protection:
Design patents. Inventors use design patents to protect the appearance or design of a functional object. Some examples of bird feeder design patents are this one and this one. Read more about design patents.
Utility patents. Inventors use utility patents to protect bird feeders with unique functional features -- for example, this squirrel-repelling feeder or this squirrel-repelling feeder or this squirrel-repelling feeder (whoa that's a lot of repelled squirrels). Read more about utility patents. (Also you can preserve your place in line at that Patent Office without filing a full patent application by filing a provisional patent application.
Trade secret. Some inventors seek to protect their rights when submitting ideas by using nondisclosure agreements (NDAs), thereby preserving trade secrets. The problem for inventors is that often the evaluating company won't sign the NDA because of concerns that they'll be precluded from developing similar ideas. Read more about NDAs and trade secrets.