- Audubon-San Francisco Bay Area. Healthy trees, healthy birds, 2-pg flyer
- California Council for Wildlife Rehabilitators, flyers for tree trimmers on squirrels and birds
Photo by Peggy Honda
- Los Angeles Audubon Society, tree trimming guidance
Sea and Sage Audubon Society, tree trimming resource packet
- U.S. Fish and Wildlife Service. Bird nests: What you need to know. 1 p.
- Tree Trimming Guide
- The Birds and the Trees by Merlin Schlumberger