I think ABS would be your best bet. It's not biodegradable and realtivley easy to print.

But you can use more or less any material if you use some form of coating on it. I would always go for coated PLA instead of other materials just because PLA is the easiest to print and it's nontoxic.

3d printing for outdoor use: what types of filament are most weather resistant?

I'd like to print modifications for my birdfeeder, both to patch over the hail damage from last summer and to try to deter the neighborhood squirrels. I have an FDM printer (and experience with nylon, ABS, and PLA, though don't restrict answers to those if there's something else that's better), what kind of filament would stand up best to daily exposure to sun, rain, snow, etc?