In the high mountain desert of southwest Colorado, the temperatures can still be bitterly cold when the first signs of spring appear.
"The cranes arriving signify that spring is here," said Michael Blenden, project leader at the San Luis Valley National Wildlife Refuge. "The Rocky Mountain population of greater Sandhill cranes spend the winter in central New Mexico along the Rio Grande valley. And starting around mid-February they move north to the San Luis Valley here in Colorado. By mid-March to early April they will be departing for their breeding grounds in southern Montana, southeastern Idaho and Wyoming."
About 26,000 cranes flock to the San Luis Valley to take advantage of the food resources and wetland habitat available at the Monte Vista National Wildlife Refuge.
"The migration of the Sandhill crane is pretty unique. There aren't too many places where we see this concentration of cranes," said Scott Miller, Biologist at the San Luis Valley National Wildlife Refuge.
"This is an important migration route," said John Rawinski, an avid birder and author of "Birding Hotspots of South-Central Colorado." "They have quite a sizable journey ahead of them. The cranes can rest, feed on the grain and prepare themselves here for the long migration ahead."
There are three subspecies of Sandhill cranes: the greater, the lesser, and the Canadian. The largest species, the greater, stand about four feet tall and has a six-foot wingspan. The cranes are mostly a slate gray color with red markings on their heads. Sandhill cranes are one of the oldest known birds according to fossil records tracing back 2.5 million years.
The Sandhill cranes are also known for their distinctive mating dance.
"Cranes typically nest for life; they travel all the time with one specific mate," said Blenden. "This time of year they are preparing for mating and part of that is a ritual called the mating dance. It's like two jesters playing with each other, bounding, dancing and flopping their wing."
The annual crane migration draws bird watchers from across the country. The unique setting of thousands of cranes congregating with the San Juan mountains as a back drop creates spectacular views for birders and photographers. In March, bird watchers gather for the annual Monte Vista Crane Festival to watch and learn about the Sandhill cranes and other wild life at the Monte Vista National Wildlife Refuge.
"Its inspirational, its motivational – it's also my form of stress management," said Rawinski. "If I come out here and spend a little time out here watching birds it seems like you're far removed from worldly issues."