When you think of migrating animals, you might picture mule deer, or wildebeest — maybe even salmon. But some of the most extraordinary migration routes are carried out by birds, ranging in size from just a few ounces to a few pounds, and it’s happening here in Utah.
“Birds live at a geographic scale that is so different than what we're used to," said Adam Brewerton, the avian conservation program coordinator with the Utah Division of Wildlife Resources. "These migratory birds think about the world in this way that I can't even wrap my head around.”
Brewerton said these migrations are made even more challenging by light pollution and difficult-to-navigate windows.
“Birds use landscape features and visual cues like stars, moon location,” Brewerton explained. “They’re really keyed into where light is and where light isn't.”
One way to reduce light pollution at home is to turn off unnecessary lights and consider installing shielded fixtures for outdoor lighting.
Brewerton said there are uniquely designed programs to aid Utahns in this very task. “Lights Out programs, Lights Out Salt Lake City, Tracy Aviary has a lot of information and resources there for people.”
Windows also pose a significant threat to birds because they’re difficult for birds to perceive.
“Windows are obviously transparent. That's why we have them," Brewerton said. "So, birds can see right through them, and often don't recognize that there's something physical and in the way of what they're just seeing right through. And then the other thing that will happen is that, depending on the angle of the light, windows can be highly reflective, and so [the window] acts like a mirror, and birds just don't recognize that they're seeing a reflection.”
If you’re finding bird carcasses below your windows — or simply want to take proactive steps — Brewerton offers some solutions.
“One of the more effective and widely used ones are window markings that help break up the pattern of either that complete transparency or something that breaks up that reflection," Brewerton said. "Commonly you'll see dots placed along windows or stringers in front of windows.”
Brewerton said there is one important thing to keep in mind if you’re taking these steps.
“The general recommendation is that any anything put on a window must have a spacing of two inches or less," he said. "Otherwise, birds will feel like they can still fly through the gaps.”
Brewerton added that simple fixes can go a long way — using black or white markers to create small dots on windows can help birds recognize the barrier. There are also specialized markers that appear clear to us but reflect ultraviolet light, making them visible to birds.
To many of us, Utah is home. But for migratory birds, it’s an important stop along vast international journey. By taking simple steps to reduce light pollution and make windows more detectable, we can help ease the challenges they face along the way.