Though migration is already well underway, we will see peak numbers of birds between mid-April and mid-May. There are a number of ways we can each contribute to helping safeguard birds on their journeys (keeping cats indoors, providing habitat in our yards, and marking our windows to prevent collisions), but one of the easiest things we can do is turn off unnecessary overnight lighting—especially during peak migration—to reduce the fog of skyglow that clouds the skies over our cities and towns, drowning out the stars and luring birds into lit areas.
Want to lend birds a hand? Researchers at Colorado State University’s AeroEco Lab use the unique signatures produced by concentrations of birds on radar maps to predict when and where bird numbers will be highest each night during spring migration. With this information, aeroecologists issue forecasts, including red, orange, and yellow alerts, that help focus our efforts on peak movement nights.
This spring, Take the Pledge to Go Lights Out, and watch our social media feeds for red alert nights when it is most critical to turn off our lights to keep our avian friends aloft!
Did you know?
- During migration, some birds modify their sleep patterns to facilitate long-distance nocturnal travels. Frigatebirds, for example, use a strategy called unihemispheric sleeping, which allows them to rest half the brain while the other half stays alert. Other birds will take brief power naps during the day. On her 3,000-mile journey between Central and South America and northern Canada and Alaska, a Swainson’s Thrush can sleep for just nine seconds at a time!
- In preparation for migration, some birds nearly double their weight (or more!) in a feeding frenzy called hyperphagia, which helps them put on fat to fuel their rigorous journeys.
The last species to arrive in Oregon include many aerial insectivores—birds like kingbirds and nighthawks whose migration is carefully choreographed to align with warming days and the associated increase in flying insects.
- Some birds talk to each other while migrating, which likely evolved to facilitate collective decision-making in flight. Researchers in the Midwest found that when these species get drawn into lit areas and vocalize, they inadvertently lure other birds in, resulting in collisions with buildings. Such birds are known as supercolliders and include Dark-eyed Junco, Song Sparrow, Hermit Thrush, Brown Creeper, Fox Sparrow, Swainson’s Thrush, and Common Yellowthroat, to name a few.
- The same researchers looked at collision rates at the Chicago Convention Center and found a 75% reduction in collision rates when the building turned off overnight lighting.
- Some Bar-tailed Godwits undertake a 6,800-mile nonstop migration from Alaska to New Zealand every fall. To achieve this feat, they absorb 25% of their liver, kidneys, and digestive tract, increase the size of their heart and chest muscles, and put on a lot of fat!
- Recent tagging has shown that Sooty Shearwaters are among the longest distance migrants on earth, with some individuals traveling over 47,000 miles each year on their figure-eight route between South Pacific breeding areas and wintering grounds in the subarctic.
- A Rufous Hummingbird measures three inches long, weighs less than a nickel, and undertakes one of the longest migrations of any bird relative to body size. They can fly nearly 3,900 miles one way from SE Alaska to Mexico (or 78 million body lengths)!