Migrators arrive after a long journey | VailDaily.com

Migrators arrive after a long journey

Emerald Gustowt
Curious Nature
Vail CO Colorado

If you’re still in town now that our ski resorts are almost closed for the season, chances are you’re either a local or a transplant that has grown roots. Either way, you’re in luck as Mother Nature sets out preparations for “her day,” Earth Day. She’s hung her decorations in the blooming trees, and invited her snowbird friends from South America to join the party. You might be lucky enough to see them celebrating by nesting and raising their young along open areas in spring and summer.

The Swainson’s hawk (Buteo swainsoni), a.k.a. locust or grasshopper hawk, is slightly smaller than a red-tailed hawk, and more slender. Most adults have light underfeathers with a reddish bib on the chest, and a white throat and face patch. When they fly over, you’ll notice a dark edge with pale flight feathers, which is unique for identification. This time of year, they are making their way to our state from the pampas (plains) of Argentina, where they feed mainly on insects during our winter (South America’s summer) months. The Swainson’s hawk has one of the longest migrations at up to 10,000 kilometers (averaging nearly 200 kilometers per day!). Large flocks can often be seen making the journey, sometimes with over 100 birds – appropriate guests to invite if you’re having a party!

These birds also have a tendency to return to the same breeding areas, and mate with the same partner each year, often using the same nest site as well. While they are here, you’ll find them in grassland areas, meadows, sagebrush, and even in hardwoods hunting for small mammals, reptiles, birds and insects. Of the large raptors breeding in northern Colorado, only the Swainson’s regularly nest near cultivated lands. In fact, you may see them following the farmer’s plow to snatch their prey from the disturbed soil. When they set up home for their new family, it will usually be in a tree or on a cliff overlooking good open hunting grounds. The female will lay two to four eggs that hatch in 28 to 35 days, so start looking for chicks beginning in early June. Both parents will care for the young, with hunting often the father’s main job.

Young fledglings are very important, as these hawks provide “pest” control, and play a pivotal role in our natural world. Like other wildlife, they are threatened by habitat loss, nest site availability, and chemical pesticides. Regular natural fires keep habitat for their prey in good shape; otherwise it becomes harder for them to find dinner. In the mid-1990s, farm pesticides in Argentina are thought to have affected 6,000 to 20,000 birds (up to 5 percent of the total population). Luckily, conservation efforts to learn about and save this species have also helped many other birds, making it an ambassador, or “umbrella species.”

Being within the American Central flyway, or bird freeway, Colorado is a great place to watch birds migrate in the spring and fall. And birds that moved to lower elevations will start to return to the mountains for the summer as well. Nobody wants to miss the party! You’re invited, too, so don’t miss out! Grab some binoculars and a field guide and get out there to meet and greet our good friends as they return from their very long flight.

“Fixing up the old nests,

Busy, busy, busy!

Bringing sticks for new rests,

Hurry, hurry, hurry!

Bits of moss and thread

Make a downy bed

To roll the eggs about

While they’re hatching out.”

-Watie W. Swanzy

Emerald Gustowt is a volunteer for Walking Mountains Nature Center, with a background in wild bird rehabilitation, and is excited to be a migrator from Florida herself.

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