Unknown effectiveness (limited evidence)

Angle windows to reduce bird collisions

1A single randomised, replicated and controlled experiment in the USA found that fewer birds collided with windows angled away from the vertical. Assessment: unknown effectiveness — limited evidence (effectiveness 60 %; certainty 20 %; harms 0 %).

http://www.conservationevidence.com/actions/166

Mark windows to reduce bird collisions

2Two randomised, replicated and controlled studies found that marking windows did not appear to reduce bird collisions. However, when windows were largely covered with white cloth, or tinted, fewer birds flew towards or collided with them. A third randomised, replicated and controlled study found that fewer birds collided with tinted windows than with un-tinted ones, although the authors noted that the poor reflective quality of the glass could have influenced the results. Assessment: unknown effectiveness — limited evidence (effectiveness 20 %; certainty 20 %; harms 0 %).

http://www.conservationevidence.com/actions/167