Keep an eye out for colorful visitors around your yard this week. Bird migration is at its spring peak!
Don’t be surprised if you notice curious observers staring or pointing up at the sky this week. It’s bird migration time — and it’s at its spring peak in the Alamo City!
San Antonio is perfectly located along the Central Flyway from Mexico north across Texas into the Great Plains and Canada. The lack of mountains and other obstructions in our wide-open spaces encourage spring birds to broadly congregate over central Texas as they make their way north toward nesting territories.
On favorable nights (like tonight) they’ll number in the many millions. You can hear them calling overhead in the predawn darkness if you pause while loading the car or rolling the bins to the curb. In addition to the mockingbird’s morning vocals, you may hear a chorus of additional whistlers and the light percussion of warblers, orioles, flycatchers and many more as they alight on the treetops after a high flight overnight.
New online tracking tools like BirdCast let you see it for yourself: 15 million birds flew over Bexar County already this week, and similar numbers are expected to pass through in the next few days. (That’s more than all the people and grackles in San Antonio, combined!) Weather surveillance radar picks up millions of tiny slow-moving targets moving northward at night when temperatures are perfect for wings to maintain speed and altitude.
Dokter, A. M. 2023. BirdCast, live migration map; 2023-05-02-0540. Cornell Lab of Ornithology. https://birdcast.info/migration-tools/migration-forecast-maps.
Since birds use the moon and stars to navigate, they become easily confused by artificial lights, especially during foggy or rainy weather. Even midnight specialists like nighthawks can be disoriented by lights around buildings, where window collisions and other dangers abound (half a billion birds die from window strikes each year.)
You can help them avoid crashing into windows and wires by switching off your own outdoor lights during heavy migration. Lights Out Texas recommends turning off all non-essential lighting from 11 p.m. to 6 a.m.
Also, keep your bird baths filled with fresh water and away from areas where predators can hide, as many migrants will linger during the day to refuel before heading on their way at sunset.
So listen and keep an eye out for colorful visitors around your yard — painted buntings, cuckoos and Baltimore orioles are all possible even in urban San Antonio.
Looking for a better view?
Everywhere is a good place to see migration this week, but birds also tend to be channeled by local topography into well-known “migrant traps” where they can be more easily seen and photographed. Check out these classic hotspots as well as the Botanical Garden, Brackenridge Park, Crescent Bend Nature Park and Mitchell Lake Audubon Center.
San Antonio Audubon Society, Bexar Audubon Society and other groups offer guided tours of many locations.
