Hummingbird Migration and Window Strike Mortality

Hummingbirds are among the smallest and most metabolically demanding birds, making them especially vulnerable to the energy cost of window strike injuries during migration.

Key Facts

Ruby-throated hummingbirds weigh about 3 grams but fly over 800 kilometers non-stop across the Gulf of Mexico
A hummingbird must eat half its body weight in sugar daily to fuel its 1,200 heartbeats per minute
Window strikes that stun but do not kill hummingbirds can cause fatal energy depletion if recovery takes too long
Hummingbirds are important pollinators for over 150 species of wildflowers in North America
A single migrating hummingbird may need to refuel at multiple specific flower patches along its route

Welfare Considerations

Hummingbirds injured by window strikes face a dual welfare problem: acute concussion injury and the energy depletion of the recovery period. A hummingbird that recovers for 24 hours without food access will fail to complete migration and may die on the route. Their extreme metabolic demands mean even brief periods of incapacitation create welfare emergencies. Given that hummingbirds frequently investigate reflective surfaces, they are overrepresented in window strike casualties relative to their population size.

What You Can Do

Apply window deterrent film or paint to windows in hummingbird migration corridors
Provide appropriate hummingbird feeders with fresh solution during spring and fall migration
If you find a stunned hummingbird, keep it in a small dark box for no more than 30 minutes before releasing
Plant native flowers that provide migration refueling stops for hummingbirds