The fall migration renews opportunity to view sandhill cranes in valley refuges
The squeaky-wheel yawping from a congregation of excited sandhill cranes is unforgettable. What’s even more unforgettable is the sight of a flock of greater sandhill cranes, the largest of three migrating subspecies of sandhill crane — greater, Canadian and lesser. With grayish plumage and a red forehead, the greater sandhill crane can reach 5 feet tall and weigh 14 pounds.
“They’re starting to arrive,” reports Ron Garcia, refuge manager of the Baca National Wildlife Refuge in the San Luis Valley National Wildlife Refuge Complex, a major stopping point for the cranes. The complex is a trio of national wildlife refuges — Monte Vista, Alamosa and Baca — managed by the U.S. Fish and Wildlife Service. The 14,804-acre Monte Vista refuge was the first of the refuges, created by the Migratory Bird Conservation Commission in 1952. The 12,026-acre Alamosa refuge followed a decade later, the 92,500-acre Baca refuge in 2000.
Garcia said that while the cranes are arriving in increasing numbers, the favorable conditions across the summering grounds has created a slow start to the fall crane migration, which often peaks in October. “Wherever they’re at they’re in decent shape and they’re not needing to rely on the valley yet.”
However, he added, “virtually the entire Rocky Mountain population will come through the San Luis Valley at some point this fall. It’s just a matter of how they come through. Are they coming through more dispersed over a longer time or are they coming through all at once?”
According to Scott Miller, senior biologist at the complex, “the population (of greater sandhills) fluctuates a bit each year but stays pretty much between 16,000 to 24,000 birds.”
“In addition to the greater sandhills,” added Miller, “we typically get anywhere between 4,000 to 6,000 estimated lesser sandhills.”
Time to Visit
It is prime time to visit the San Luis Valley to see these charismatic birds in their fall migration.
“Typically,” said Garcia, “by mid- or the end of October, the majority of the birds are gone from the valley.”
From the valley, the birds head south.
“They primarily follow the Rio Grande right down into New Mexico,” said Garcia, “and some of them disperse from there. The major wintering grounds for this population is the Middle Rio Grande Valley, and some disperse east, west and south even from there.”
Weather is a major factor of when the cranes will leave the San Luis Valley. When roosting areas in the wetlands are unfrozen, cranes tend to stick around. The tall birds stand in the water during the night to avoid predators. When the water freezes, the birds are vulnerable and head out.
To help the cranes stick around, the refuge floods the wetlands with water from artesian wells to maintain roosting habitat, much of which is within view of either side of Colorado Highway 15 from auto pullouts just a half-mile south of the Monte Vista refuge’s visitor center.
The wetlands have already been flooded. “We’re ready for them,” said Garcia.
Unlike the spring migration, which congregates in the refuges to feed on unharvested grain, Garcia said the fall migration disperses birds across the valley on private lands to feast on wasted grain from the fall harvest.
To view the birds, Garcia suggests starting at the refuges where they roost. “They really are off the autotour route or off of Highway 15. Just after sunrise and just before sunset is typically when they’re flying between their feeding and their roosting grounds. My recommendation would be to go early, sunrise, to see where they’re flying out of their roosts and follow them.”
And there’s more to see than cranes. The complex provides a haven for migratory birds, songbirds, raptors, water birds and other wildlife like mule deer, coyotes, rabbits and beaver. Canada geese and ducks, especially mallards, are bountiful at the refuges. About 40 percent of the Monte Vista and Alamosa refuges are open to waterfowl hunting in the fall, but this takes place apart from prime viewing opportunities.
The 2020 37th Annual Monte Vista Crane Festival will be March 6 – 8. Registration opens on January 2, 2020.