Penn State study: average Amish farm has 40-60 bird species. Industrial farm across the road — 10-15. 4x more.
Why
Hedgerows (industrial farms remove — hinder machinery). Trees (shade, nests). No pesticides (insects exist = food for birds). Crop diversity (varied food). Compost piles (worms, beetles). Horse manure (flies → starlings).
Birdhouses
Amish children build birdhouses in shop class. Every field — 2-3 birdhouses. Bird eats insects that eat crops. Free pesticide. With a song.