Providing evidence to improve practice

Action: Angle windows to reduce collisions by birds Bird Conservation

Key messages

A single randomised, replicated and controlled experiment in the USA found fewer birds collided with windows angled away from the vertical.

Supporting evidence from individual studies

1 

A randomised, replicated and controlled experiment in 1991 in Pennsylvania, USA (Klem et al. 2004), found that a fewer birds collided with windows angled at 20o or 40o from the vertical (28% and 15% of 53 recorded collisions respectively) than with vertical windows (57% of collisions). Six plate glass, wooden framed windows (1.4 x 1.2 m, 1.2 m off the ground, 15-43 m apart) were used, between January and May, on the edge of deciduous woodland and farmland.

Referenced papers

Please cite as:

Williams, D.R., Child, M.F., Dicks, L.V., Ockendon, N., Pople, R.G., Showler, D.A., Walsh, J.C., zu Ermgassen, E.K.H.J. & Sutherland, W.J. (2017) Bird Conservation. Pages 95-244 in: W.J. Sutherland, L.V. Dicks, N. Ockendon & R.K. Smith (eds) What Works in Conservation 2017. Open Book Publishers, Cambridge, UK.