We have a bird problem. Since we live in the woods, there are lots of birds around, but except for a few spots on windshields they usually aren't much of a problem. But for the last three days a large male robin has been battling his own reflection in our sunroom door. This bird brained warrior flies against the glass for hours on end. He is losing the fight because there are specks of his blood all over the glass. But he keeps at it.

Evolution did not teach him how to deal with his own reflection in glass. All through those millions of years while his instincts developed, there was no glass. Now, for the first time in eons, robins are seeing their own reflection, and they take it to be another robin intruding on their territory. So they instinctively fight.

This bird is a really slow learner. He starts at daybreak and doesn't quit until after sunset. I took a sheet of plywood out on the deck and leaned it up against the door. Unfortunately we have more glass doors than we have plywood, so he just moved over and continued the fight.

A bird's brain is much simpler than the brain of a mammal. They can learn, but only on a limited scale. I hope it doesn't take too many millions of years for them to learn about glass. They might become extinct.
Howard