Each spring, the animals of the world are in motion again—flying, swimming, running and crawling to their summer homes and breeding grounds. The Nature Conservancy celebrates this annual pageant of nature with a listing of the “Top Five Must-See Migrations” in Colorado.
“We don’t realize that we miss some species until they suddenly return from wherever they’ve been—what a relief and a thrill,” explains Chris Pague, director of conservation programs for The Nature Conservancy in Colorado. “To see and hear tens of thousands of sandhill cranes lift into the air, along with thousands of geese and ducks, is a powerful image and one that is repeated year after year.”
“One of the greatest conservation challenges is going beyond protecting breeding grounds and wintering grounds to make sure that migrations have the places to happen,” he continues. “It is one of nature’s most important events, and one worth protecting for future generations to enjoy.”
The Top Five Must-See Migrations for Colorado
1. Swainson's Hawk
A truly remarkable long-distance migrant, Swainson’s hawks winter in the grasslands of northern and central Argentina, and then migrate over the rainforests of South and Central America, across the Chihuahuan Desert and into western North America to nest.
Early to mid-April marks the arrival of the Swainson’s hawk into the plains of Colorado. This time of year, they seem to magically appear on their nesting sites, mainly the grasslands of eastern Colorado. Also, in September, these birds migrate south again along the Colorado Rocky Mountain Front. As many as 1,300 can be seen in 3 hours!
2. Sandhill Cranes
Nearly the entire Rocky Mountain population of sandhill cranes — approximately 20,000 cranes — can be found in Colorado’s San Luis Valley in the spring and winter in preparation for their northward migration to breeding locations. The birds arrive in late January and leave by early April.
Spring migrants stop in the San Luis Valley to fatten their bellies in grain fields, wet meadows,and marshes. In fall, cranes can be found near Hayden and Craig, Colorado. Hundreds of birds that bred in Colorado and areas further north stay in the Yampa Valley from mid-September to mid-November. From there they migrate south to the San Luis Valley or directly to Bosque del Apache National Wildlife Refuge, New Mexico.
3. Rufous Hummingbird
Among the earliest returning fall migrants in North America, the Rufous hummingbird is abundant at the Conservancy’s Carpenter and Zapata Ranches between mid-June and September. These small, pugnacious birds travel to and through Colorado toward their wintering grounds, finding comfort in flower gardens, hummingbird feeders and wildflower meadows throughout the state’s mountain ranges. The species is known for its bully-like behavior at bird feeders and flowers, chasing other hummingbird species (and the occasional tanager or oriole) away to keep the food source all to itself.
4. Mountain Plover
From mid-March through April, in the great grasslands of eastern Colorado, mountain plover arrive from our neighbors to the southwest—Arizona, California, Mexico and New Mexico. They can be seen in the Pawnee and Comanche National Grasslands and in almost every remote prairie dog town, especially along Colorado Route 72 in Lincoln County.
This species was once common and relatively widespread in eastern Colorado and the mountain parks. They arrive during the late winter in the Colorado prairies. Birds remain in small flocks for a while, often enduring snow and high winds, before pairing off and breeding.
5. Warblers, Vireos, Flycatchers and Buntings
Just as the cottonwood, aspen, and willows begin to leaf out--from mid-April to mid-May—these songbirds, mostly from Central America and Mexico, arrive and fill much of Colorado with their songs. These species vary from the brilliant yellow warblers and bright blue lazuli buntings and the more subtle beauty of flycatchers, and can be seen throughout Colorado, especially around riparian areas with willows and cottonwoods.