Whenever I hear the supposed numbers around bird death attributed to both cats and buildings, they seems enormously exaggerated:

In Canada, tens of millions of birds are killed annually by crashing into glass on buildings, most of which are low-rise or residential.

Tens of millions? We should be seeing piles of dead birds all around low rise building all over Canada. I haven’t been to Canada in 20 years, but I don’t recall that being the case. If that were true of Canada, then it would be true of America, too, and that certainly isn’t the case. I seldom see a dead bird. I don’t ever recall being in a house when a bird hit a window, and I’m an old guy. I’m sure plenty of people will say it happened to them ONCE, but tens of millions of times? Bird strikes on windows would be routine.

I recently read that the massive bird deaths attributed to cats are exaggerated. It turns out that those studies are greatly flawed. It seems that the decreases in bird populations are due to MANY factors, of which windows and cats are only 2, and have been there for a long time. Other factors, like Climate Change, urban sprawl, real estate development, pesticides/ herbicides, various predators besides cats (owls, hawks, eagles, squirrels, raccoons, crows, etc.), etc.

Everybody has a pet reason for the decrease in bird populations, and they’re all right.