Patricia Homonylo was awarded the Overall Winner of the international Bird Photographer of the Year Award. Her photo, “When Worlds Collide,” is a powerful reminder of the perils that glass windows pose to avian species.

Her image shows over 4,000 birds that died colliding with windows in Toronto. Homonylo is a conservation photographer who works with the Fatal Light Awareness Program to save window collision survivors in Toronto. “Sadly, most of the birds we find are already dead,” she said. “They are collected and at the end of the year we create this impactful display to honour the lives lost and increase public awareness.” She added that over one million birds die each year from windows strikes, and that’s in North Amercica alone.

The problem is not irreversible. People and businesses can install special windows that dramatically decrease window strikes. Check out advice from the Fatal Light Awareness Program here. You can view all of the Bird Photographer of the Year winners here

Here is a sampling of these remarkable photos.

A photo of a peregrine falcon practicing his hunting skills on a butterfly won the silver award in the bird behavior category of this year’s Bird Photographer of the Year. Taken in California, photographer Jack Zhi said that although he had been photographing peregrines for years, he had never seen them play with butterflies.

‘Black Grouse’ by Markus Varesvuo