Birds and window panes

posted in: Collision-Reflection | 0


Our earlier post on “An eagle called on the Director, SBG” had a comment by Morten Strange: “What is absolutely weird in this case is that the window broke, I cannot
 recall another case like this, the impact must have been tremendous! It is a
 wonder the bird didn’t get fatally injured,”

Eddie Chapman, who runs Birding Scandinavia from Voss, Norway, has this to say on Morten’s comment: “I used to work in the glass industry many years ago. One of my jobs was 
replacing broken windows. On at least four occasions that I can remember, I 
was called out to do repair work where birds of prey had hit the window and
 broke it. These were usually Eurasian Sparrowhawk (Accipiter nisus) or Northern Goshawk ((A. gentilis)). Not
 once did I find a dead bird of prey under the broken window, and on two occasions, I was told by the house owner, that the birds of prey were trying
 to catch smaller birds and crashed into the glass while doing so.

Wang Luan Keng wrote: “I once had a Yellow Bittern (Ixobrychus sinensis) hit the window of the lab in the National Institute of Education. It was a very loud knock but the window did not break. We went out and found the bittern on the ground, almost dead and the bill had a bent tip!

“Another time, a bunch of crows were chasing a female Asian Koel (Eudynamys scolopacea) in the Singapore Botanic Gardens. The koel eventually knocked into the trunk of a tree and fell. When it was brought to me, blood was oozing out of its mouth. I knew the skull had cracked. It died shortly.

“Many people have also sent me birds that they have picked up from their house or workplace. On autopsy, many have a cracked skull or bent/broken bill. These birds are mostly small-medium sized ones like pittas, pigeons, bitterns, koels, etc. I guess these smaller birds are not as lucky as the eagle.

“In the States, many people hang window ornaments on their glass doors and windows to warn birds against flying into them. In Singapore, we don’t seem to have this practice. In fact, we just keep building more glass buildings and killing more birds!”

Sparrowhawks may escape death after crashing through the glass of windows but smaller birds may not be that fortunate.

Whatever it is, in the United States, it has been estimated that as many as one billion birds are killed each year through collisions with glass. Ornithologist Daniel Klem Jr. claims that only habitat destruction kills more birds.

When the glass is clear, birds see the other side and fly through. With reflective glass, birds see the reflected sky and trees. Either way, they usually end up dead. Many times you may not see an actual corpse, as a cat may have taken it. But there would always be a distinctive smudge on the window if the glass pane is not smashed.

Image of the seafront at Gottensburg, Sweden by YC.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.