UV patterned glass can be an excellent solution but it is important to recall that not all birds can see ultraviolet, and there is little or no UV early in the morning and on overcast days. However, migratory passerines, the most frequent victims of collisions, can see UV. It is important to consider what birds will be most likely in the vicinity of a new structure – a suburban office park and a city high rise might threaten different bird populations.