The glass doesn't look like glass to them
A window kills by reflection: at the right light angle, your glass is a convincing image of sky and trees, and a bird flying toward habitat meets architecture at speed. Feeder yards have a special duty here — we're concentrating traffic near our houses — and the good news is that strike prevention is a solved problem with known geometry and cheap fixes. This page is the short version every feeder yard should run.
The placement rule: 3 or 30
The counterintuitive standard, used throughout our placement advice: put feeders within 3 feet of the glass or beyond 30 feet — never in between. The logic: a bird flushing off a feeder three feet from the window can't build lethal speed before contact (close strikes are bumps); a bird thirty-plus feet away has room to maneuver and rarely targets the glass; the deadly zone is the middle distances, where a panicked bird hits full speed exactly at the pane. Window-mounted feeders like the clear window tray live safely at the "3" end of the rule — point-blank turns out to be the safe distance, which surprises everyone once.
Audit which windows matter: the killers are the big panes that reflect open sky or yard, and any glass with a see-through line to another window (birds attempt the "corridor"). Those get the treatments below; the small north-facing bathroom window probably doesn't need anything.
Treatments that work (spacing is the whole game)
The principle: birds need to perceive the glass as a barrier, which means exterior-side markings dense enough that a bird won't aim for the gaps — the working standard is the 2-by-2 rule: elements spaced no more than 2 inches apart in both directions (small birds will thread anything wider). What that means in practice: exterior dot or square grids (purpose-made films and tapes), tempera-paint patterns (cheap, seasonal, surprisingly fine-looking), insect screens (excellent — they break the reflection and the impact), or closely spaced cord curtains hung outside the pane. All of these work because they're outside, where the reflection lives; interior decorations barely register through the mirror effect.
The myth to retire: the lone hawk decal. A single silhouette sticker does essentially nothing — birds simply aim past it. Decals only work as a dense grid (back to the 2-inch spacing), at which point any shape works and the hawk was never the active ingredient.
If a strike happens
The humane protocol, briefly: a stunned bird sitting below the window gets quiet observation from a distance first — many recover within minutes and leave. If it's still grounded after a short while, or visibly injured, the standard advice is a ventilated box in a dark quiet spot, no food or water, and a call to your local wildlife rehabilitator — and please don't improvise care beyond that; rehabbers exist for exactly this. A window that strikes twice is telling you it's a priority pane for treatment.
Repeated strikes also interact with the rest of the yard system: if your bath or feeder station faces a big reflective pane, re-running the placement rules is part of the fix, not just the glass treatment.
The window program, in one table
| Move | Spec | Notes |
|---|---|---|
| Feeder distance | Within 3 ft or beyond 30 | The middle is the kill zone |
| Window feeder | Mounted on the glass | The safe extreme, plus the view |
| Markings | Exterior, ≤2" spacing both ways | Dots, tape, tempera, cords |
| Screens | Cover problem panes | Break reflection and impact |
| Decals | Only as a dense grid | The lone hawk is decoration |
| After a strike | Quiet, box if grounded, call a rehabber | No food/water, no improvising |
FAQ
Why do birds fly into windows?
Reflection — at many angles glass mirrors sky and vegetation, and birds fly toward the image. Dawn, dusk, and migration seasons concentrate the risk; big yard-facing panes do the killing.
Where should a feeder be so birds don't hit the window?
Within three feet of the glass or beyond thirty — never the middle distances where a flushing bird reaches full speed at the pane. Window-mounted trays are, counterintuitively, among the safest placements.
Do hawk decals stop window strikes?
A single decal, no — birds aim around it. Any marking works only as a dense pattern with gaps of about two inches or less, applied to the outside of the glass.
What do I do with a bird that hit the window?
Watch quietly from a distance first — many recover and leave within minutes. If it stays grounded or looks hurt: ventilated box, dark and quiet, no food or water, and call a licensed wildlife rehabilitator.
The Sunday Perch
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