Bird Window Collisions: How to Protect Birds During Spring Migration

If you’ve been watching your yard lately, you already know there are more birds, more movement, and a lot more activity in general— even compared to just a few weeks ago. 

That’s because May is peak migration in Ontario. It's a time when warblers, orioles, thrushes, and many other species are passing through or settling in for the season. It’s one of the most exciting times of year for birdwatching.

It’s also when one of the most common, and preventable risks, becomes most important.

Yellow Warbler. Photo by Heather Kerrison. 

The Hidden Risk in Our Own Backyards

Each year in North America, millions of birds die from window collisions.

What surprises most people is this:

The majority of these collisions happen at homes, not office towers.

During migration, birds are moving through unfamiliar areas, often quickly and at low heights. When they encounter glass, they don’t see it as a barrier.

They see:

• Reflections of trees and sky
• Open sightlines through windows
• A clear path forward

And they fly straight into it.

Why This Time of Year Matters Most

Right now, birds are:

• Traveling long distances
• Moving through new environments
• Stopping briefly to rest and refuel

They don’t have time to learn which spaces are safe.

At the same time, your yard is likely more active than ever: feeders are busy, trees are filling in, and reflections become stronger.

It’s the perfect combination for collisions to happen.

What You Can Do (It’s Simpler Than You Think)

The good news is that small changes can make a big difference.

1. Make Your Windows Visible

Adding decals or markers helps break up reflections so birds recognize glass as a barrier.

Options like UV-reflective decals or Feather Friendly® markers are designed to be highly visible to birds while remaining subtle to us.

Browse Decals + Feather Friendly →

Feather Friendly decals. Photo by Kristen Martyn. 

2. Rethink Feeder Placement

Where you place your feeder matters more than most people realize.

• Within 3 feet of a window means birds can’t build up speed
• More than 25 feet away reduces confusion from reflections

Window feeders are also a great, safe option for close-up viewing.

3. Reduce Reflections

Simple adjustments can help:

• Partially close blinds or curtains
• Add screens or external elements
• Be mindful of reflections during early morning and evening

4. Pay Attention and Report Collisions

If you’ve ever heard a “thump” against a window, you already know how sudden this can be.

Taking a moment to assess your window, especially now, can help prevent future strikes. You can also help researchers track this problem. If a bird strikes your window, report it to the Global Bird Collision Mapper. You’ll be contributing to important conservation data.

With these small, thoughtful changes, we can keep birds flying safely and help ensure they return again next season. Let’s protect the birds we love.

Happy spring bird watching!

Warmly,

Heather