.......One of my favorite examples from the article was about how birds of prey, kestrels in particular can see UV....
I visited my son an DIL yesterday and they although living in a city have an extended family of Red Shouldered hawks living in their wooded yard. There are 3 generations. An original pair and two years of offspring.
One of this years was found on the ground partially fledged. He is thought to have fallen from the nest and injured himself. He has almost no fear of humans and actually likes to rest on their deck. He brings messy presents of prey in the form of dead birds or rabbits or squirrels. He is thought to be retarded because he hangs around all the time and squeals his hawk squeal constnantly.......hours at a time. He gets up early too.
To bring the thread current, he would fly into their picture window looking out on the deck. He messed it up pretty good.He did it a lot. Hence retarded as in he wouldn't learn.
Any way, they bought some plastic maple leaves that stick to the window. They emit ultraviolet that looks clear to the human eye. Under certain conditions when viewed from outside they are faintly purple. They stopped the flights into the window immediately!!
Any way, they bought some plastic maple leaves that stick to the window. They emit ultraviolet that looks clear to the human eye. Under certain conditions when viewed from outside they are faintly purple. They stopped the flights into the window immediately!!
I was thinking of that reading your post. Older windows would have no UV absorber, so they would look transparent. But windows with UV reflective (or absorbing) film (used to protect interior contents from UV degradation or bleaching) would appear opaque or only partially transparent to a bird. It would be enough of a visual cue for the bird to avoid flying into it.