Why birds fly into windows

#FlashbackFriday This was originally published in April 2017

Anna Pidgeon, Associate Professor
Department of Forest and Wildlife Ecology
UW-Madison College of Agricultural and Life Sciences

Total Time – 3:06

0:20 – Why do birds fly into windows
0:43 – Risk factors for birds
1:23 – Other Hazards
1:48 – What can we do
2:19 – Bird feeder placement
2:55 – Lead out


Sevie Kenyon: Why birds fly into your windows. We’re visiting today with Anna Pidgeon, Department of Forest and Wildlife Ecology, University of Wisconsin-Madison in the College of Agricultural and Life Sciences and I’m Sevie Kenyon. Anna, everyone has heard or seen a bird fly into a window can you give us an idea on why that happens?

Anna Pidgeon: Birds are apparently unable to perceive glass. When they see a reflection in the glass they perceive it as open sky or as habitat or if they see through the glass to plants inside of the building or if they see through the glass to other side they don’t recognize there is a solid surface in between them.

Sevie Kenyon: Can you describe the risk factors and times for birds?

Anna Pidgeon: Situations in which birds are in close proximity to expanses of glass that reflect habitat are dangerous situations. And those can occur when birds are foraging during the day or they can happen on migration, and during migration many bird species launch into the night around sunset. They fly for several hours and then they come down to rest and re-fuel and when they land near houses in this unfamiliar territory and they’re looking around for food they often run into glass.

Sevie Kenyon: What other hazards do we have for birds out here? We’ve got the buildings and the windows are there other hazards?

Anna Pidgeon: Habitat loss is the primary factor causing mortality of birds, but beyond that cats are by our best estimates the biggest direct mortality factor caused by humans. And then, building collisions are right up there at number two. Other factors include collisions with automobiles and collisions with wind turbines etcetera.

Sevie Kenyon: Are there things we can do with our buildings to make them more bird friendly?

Anna Pidgeon: There are design considerations and there are considerations for where feeders are placed and if you are dealing with existing structure there are add-ons that are one can do to make the building more friendly. So, for example in a new building construction, using glass that has patterns etched into it called fritted glass which birds can perceive, is a really safe way to design your home to be bird friendly.

Sevie Kenyon: Is there anything to be gained by where you place your bird feeders?

Anna Pidgeon: Oh, absolutely. The best practices are to put your feeder quite close to your house so that when birds leave the bird feeder suddenly because they’re startled or whatever, they aren’t able to build up enough momentum to hurt themselves if they do mistake the glass window for habitat. And another thing that you can do if you have feeders is to put netting up or other, birds can perceive UV light, so you can put decals up that they perceive strongly in the UV section of the electromagnetic spectrum that we don’t perceive so well, but those need to be reapplied because UV degrades in sunlight.

Sevie Kenyon: We’ve been visiting with Anna Pidgeon, Department of Forest and Wildlife Ecology, University of Wisconsin-Madison in the College of Agricultural and Life Sciences and I’m Sevie Kenyon.



Sharing is Caring - Click Below to Share