Dawn Plus 10 Million Years
Sandhill cranes again flying high after near decimation
Before the sun even hints of rising above the San Pascual Mountains to the east, before the sky turns from black to burnt orange to gold, the shadows on the water begin to move. First one, then another and another, until the shallow lake becomes a blur of motion and a cacophony of noise – rattling, rolling, haunting calls that reverberate across the marsh like an ocean wave.
It is dawn plus 10 million years.
The shadows on the New Mexico waterway belong to sandhill cranes, the oldest living bird species in the world. There is fossil evidence from Wyoming that sandhills have been on earth nine to 10 million years, that they may actually have evolved in North America. And they’ve been coming to this wild, rugged corner of the Rio Grande Valley and the Chihuahuan Desert for much of that time.
Click image for the photo gallery:
Today the place is named Bosque del Apache National Wildlife Refuge, where since 1939, the U.S. Fish & Wildlife Service has been helping these ancient creatures survive in a world that had seemingly turned against them. Uncontrolled hunting and habitat destruction in the early years of the century had reduced the sandhill population to dangerously low levels; in 1941, just 17 sandhills spent the winter months at the new refuge. Today that number has climbed to as many as 17,000.
As impressive as these numbers may seem, they pale in comparison to the numbers of sandhills that concentrate a little further northeast along a 60-mile stretch of Nebraska’s Platte River. There, each March, half a million sandhills come to re-fuel and build up body fat for the remainder of their migration and the breeding season. Some will only go as far as the Yellowstone country, others will continue further into the Canadian sub-Arctic, and even others will travel as far as Siberia.
“In many cases, the birds breed so far north that human encroachment is not really a problem,” explains Anne Lacy, Crane Research Coordinator for the International Crane Foundation in Baraboo, Wis., “and this undoubtedly has helped sandhills survive so long. The problems the birds face today primarily center around their crucial staging areas like the Platte River, where demands on water usage have changed the river’s flow.
“Habitat management is the common issue facing most wildlife species today, but at least in the case of sandhills, the different factions have been able to sit down and discuss the problems and search for solutions. The cranes seem to have that kind of effect on people.”
Standing nearly four feet tall on their spindly legs, weighing about 10 pounds, and dressed in dull gray feathers with a wingspan of six feet, it is not difficult to imagine sandhill cranes staging in unimaginable numbers and repeating such lengthy migrations for millions, of years. The birds simply look prehistoric, but they can remain aloft for as long as 24 hours if forced to, during which time they may cover more than a thousand miles. They can reach speeds of 60 miles an hour with a good tailwind, and climb as high as 26,000 feet. Some will live more than 30 years, during which they may fly more than 100,000 miles.
“Overall, the sandhill has to be considered one of the most remarkable wildlife species in the world, not only because it has survived so long, but also because of how it has survived,” continues Lacy. “The total sandhill population, including the six subspecies, numbers between 500,000 and 600,000 birds, so overall it is doing well.”
Mankind has been enthralled with cranes for thousands upon thousands of years, and we still are. Native Americans believed cranes flew away each autumn to search for the previous spring, which they would bring back when they returned. Greek and Roman scribes, including both Aristotle and Herodotus, wrote about cranes, and archaeologists excavating Egyptian tombs dating to 4,500 B.C. found burial chambers lined with figures of cranes carved into the limestone walls.
A Chinese flute carved from a crane bone 9,000 years ago still played when it was unearthed just a dozen years ago. To most societies, cranes represented longevity, good fortune, and nobility.During the birds’ brief six-week stay on the Platte, tens of thousands of visitors come to observe, photograph, or just have their own spirits rekindled by these prehistoric creatures, and they spend some $50 million to do it each year.
In ancient times, sandhills began wintering at what would become Bosque del Apache and then stopping on the Platte because in both places they found their specialized roosting, food, and water requirements met. Even today the Platte is the only place along their migration path that meets their needs. The birds spend each night in shallow water, preferably a sand or mud bar surrounded by deeper water. There they stand, often on one leg, protected from predators by the water. Ancients believed the birds held a rock with their raised foot, ready to drop and wake the other sleeping birds with its splash if a predator did approach.
They’re vegetarians, preferring the dry side of their generally marshy habitat where land and water meet, and although sandhills may look similar to egrets, herons, and other long-legged waders, they are not related. Sandhills mate for life; they are ground nesters that rarely perch in trees; and they don’t nest in rookeries but in isolated pairs. Because this leaves them so vulnerable while laying eggs and caring for their young, over the eons sandhills have developed a trait known as “feather painting,” in which the birds daub mud and sediment over their wings and back to help camouflage themselves.
At Bosque del Apache, more than 50 miles of irrigation canals have been constructed to literally create marshes and ponds in the desert with water diverted from the Rio Grande. After the sandhills depart in March, the impoundments are drained, plowed and burned, then re-filled to allow a new growth of sedges and millet that will be awaiting the cranes’ return in October. Sandhills aren’t the only ones to enjoy this bounty; as many as 50,000 snow geese come in as well.
Although greatly outnumbered, it is the sandhills that take center stage. Perhaps it’s the size difference between the cranes and the geese, or maybe their different food requirements, but I’ll just bet it’s a recognition of seniority, especially during those gray-black pre-dawn hours when the shadows on the water begin to move.