Patient of the Week: Window Collision Causes Swainson’s Thrush to Miss Migration Window

By Ashley Lema, Wildlife Rehabilitator

On October 16, 2020 we received this Swainson’s Thrush, who was brought to our Wildlife Care Center after hitting a window in Clackamas, Oregon. The good Samaritan said the bird remained still with their head turned to the side after the collision and was having trouble flying away afterwards. They made the right decision to bring the bird in for care. Once our staff were able to examine the thrush, they found an injury to one of the eyes. With medication and time to recuperate, the thrush healed and was ready to be released. However, Swainson’s Thrushes are migratory, and this bird was on their journey south when they flew into a window. After weeks in care, all of their fellow Swainson’s Thrushes were long gone from the area. Unfortunately this meant they had missed their migration window and were going to have to stay with us over winter, until their species returned. We are now eagerly awaiting their arrival, and will release this bird once we see others in the area!

The Swainson’s Thrush perched on a natural branch in their outdoor enclosure.
The Swainson’s Thrush perched on a natural branch in their outdoor enclosure.

From hummingbirds to swans, millions of birds migrate across North America every year, covering hundreds to thousands of miles. Bird migra­tion takes advantage of seasonal surges in pro­tein (like insects) and other nutrients (like fruit) that are necessary for breeding. While long-distance migratory birds use stopover habitats by day, most birds make these remarkable and perilous journeys at night by visualizing the magnetic pull of the earth and using the moon and stars to set their course. 

As migrating birds pass over brightly lit cities, skyglow drowns out the stars, confusing them and luring them into our urban areas. Once trapped in the windowed maze of the city, birds either hit buildings directly or circle them until they collapse from exhaustion. During spring and fall migration, significant numbers of birds (including Swainson’s Thrushes) die from collisions with windows. Turning off unnecessary overnight lighting helps us not only save energy, but helps birds make it to their destinations safely! 

Click here to see how many birds will be passing through Oregon during migration each night, and which nights have a lights out alert due to the high volume of birds in our sky.

Swainson’s Thrushes are medium-sized songbirds, with slim bodies, large buffy eye rings, mostly brown feathers with pale underparts, and a spotted chest. Swainson’s Thrushes become numerous across most of North America’s forests during the migration seasons (including at our own Wildlife Sanctuary). They forage in trees and on the ground, looking for insects mostly, but will also eat small fruits.


Why Do Birds Hit Windows? And How Can I Help?

    • Birds cannot perceive windows as barriers, and sometimes see the reflection of trees or the sky and think it’s a continuation of habitat, not a solid barrier. Because of this they often fly at full speed straight into our windows. Nearly half of the birds will die on impact, others can be lucky and only become stunned for a short period of time and can fly away soon after the strike. Many birds suffer injuries such as neurological damage, fractured bones, eye trauma, internal bleeding, air sac complications, etc.
    • Nearly half of all window strikes happen at residential homes, or most commonly within the first 3-4 stories of a building. As Portland grows, the risks to birds also increase. You can help by minimizing the incidence of window strikes at your home or business by making your glass windows visible to birds and reducing light pollution. Click here for more tips regarding DIY solutions, naturescaping, decals/window film, netting/screens.
Swainson's Thrush
Swainson's Thrush, photo by Hayley Crews.

What to Do If A Bird Hits Your Window

    • Observe from afar so as to not stress the bird further. Some window strike victims recover quickly and are just “stunned.” However, in this state, the bird may be vulnerable to predators. If possible, you can gently cover the bird with a towel, and place them in a shoebox or other container you can secure, then place them somewhere quiet and safe.
    • Wait 1 hour, then attempt to open the box outdoors. Hopefully the bird will be alert and be able to fly away. Do not try to throw the bird to get it to fly; this can cause more injuries than they initially had. If you did not contain the animal, check back in an hour to see if they are in the same area.
    • If the bird doesn’t fly away, the best thing you can do is contain the animal in a securely closed (but ventilated) box and keep the animal quiet and undisturbed until you can transport it to your closest wildlife rehabilitation facility. Do not offer food or water.
    • Take action to prevent further injuries at that window!
    • Take the Lights Out pledge.

Bird Alliance of Oregon’s Wildlife Care Center accepts new patients from 9 a.m. – 5 p.m. every day. You can also leave a message on our Wildlife Hotline at (503) 292-0304 or email and one of our wildlife solutions counselors will get back to you and provide advice for your specific situation.


Unfortunately due to COVID-19 we had to operate our Wildlife Care Center this past year with about 20% of our normal staffing and with about a 25% increase in our annual patient admissions. We were left with the difficult but necessary decision to discontinue providing follow-up updates on patients brought into our center so that we could focus on the daily care of the animals. And while we simply cannot write a story about each animal, our goal for this fresh and bright new year is to show you what we can: in the form of a weekly patient update! Check in every Thursday for our “Patient of the Week”; with information on the species, the circumstances that brought the animal in, and preventative advice so you can be a better steward for our wildlife!

If you’d like to contribute to the Wildlife Care Center, please consider making a donation here. Your support helps us save lives.