Bird-Strike Prevention for Wildlife-Friendly Gardens

Migratory birds along the “Pacific Flyway” are attracted to our Davis, California wildlife-friendly yard. Thanks to Audubon (https://www.audubon.org/news/reducing-collisions-glass) and Acopian Bird Savers (https://www.birdsavers.com) for the information on the parachute cord system for preventing bird strikes. Based on the guidance from these websites, I installed this panel which is removable, if needed.

I used 1/16 inch by 3/4 inch angled aluminum extrusion and drilled holes every 4 inches, the distance found to effectively deter birds from flying through. I attached the metal to the walls above and below the 8 foot-wide windows in three places each using 3/16 inch by 2.5 or 3 inch long hanger bolts (lag screws on one side and bolts on the other side). The screw side goes into the wall and the metal is then attached to the bolt side, sandwiched between two wing nuts that hold the metal out away from the window and firmly in place. I measured out a single strand of parachute cord and, before cutting the cord, taped the cord at the length I needed for the whole window (e.g., 2 feet x 21 “bars”, plus 1/3 foot x 21 spaces = 49 feet total). I made sure to overestimate the length of cord I needed by adding a few feet.