In September of 2019, the American Bird Conservancy published a compilation of tests for products designed to prevent window strikes. The project was supervised by Christine Sheppard, Ph.D., Director of Glass Collisions Program at American Bird Conservancy.

Wild birds were given a choice of flying down a flight tunnel with clear glass covering the departure point or flying down a flight tunnel with clear glass protected with WindowAlert decals at the departure point. The departure point in both tunnels was protected by a nearly invisible, tiny filament netting. This netting prevented any bird from being injured during the tests.

A video camera recorded flights and computer recorded flight data. Birds tested were resident species netted during migratory season. Nearly all test subjects were migrant passerines.

The WindowAlert decals used for the study were of Classic Square design. Tests were done using the Classic Square as well as the Classic Square cut to 50% of its normal size.

The results of the study were as follows:

Decal Spacing (Horizontal x Vertical) Columns x Rows Results
Classic Square 2.4 cm x 5.0 cm 3 x 7 92% decal avoidance
Classic Square 4.3 cm x 5.0 cm 2 x 7 78% decal avoidance
Half Square 2.4 cm x 5.0 cm 3 x 13 92% decal avoidance
Half Square 4.3 cm x 5.0 cm 2 x 13 74% decal avoidance
  1. These tests reveal a high success rate for WindowAlert decals with birds avoiding the decals up to 92% of the time.
  2. Full-size decals perform better than half-size decals (78% v 74%) when more openly spaced (4.3 cm v 2.4 cm horizontal).
  3. Finally, closer spacing of decals to one another also improves performance (92% v 78% success).

For a copy of the full report, click here: 2019 ABC Study