Sandhill Cranes: Epic Migration & Whooping Crane Encounters | Nature Documentary

If the looks and call of the Sandhill Cranes seem a bit prehistoric, perhaps that's because their ancestry dates back millions of years. With a population of over a million birds, today they are the most abundant of the North American cranes. And each year, they undertake the longest migration of any crane species on the planet. This age-old migration begins here in the South. I found these ones in Southwest Arizona, where they spent a great deal of their day feeding in the local area corn and alfalfa fields. In late February, their numbers start to thin out as they begin making their northward migration. Unlike songbirds and waterfowl, Sandhill Cranes migrate mostly during daylight hours. Highly efficient flyers, they are adept at using thermal updrafts to rise thousands of feet in the air. They conserve energy then by gliding, until they catch another thermal, and this process begins all over again. In March, the Central Flyway is witness to one of the greatest wildlife spectacles in all of North America. As the flyway narrows over Nebraska, their numbers become concentrated, and in just a few short weeks, as many as 600,000 Sandhill Cranes will pass through here. Early pioneer settlers described the Platte River as a mile wide and an inch deep, and while this will not support river navigation or power generation, this braided river system is an ideal place for cranes to roost at night. They begin arriving at sunset. Silhouetted against a bright orange sky, their sound and numbers are astounding. Gracefully touching down, they begin to form large roosts, and continue to do so until well after dark. The cranes will spend their night here. Using a process known as unihemispheric slow-wave sleep, one eye closes as half their brain enters into a deep sleep. The other half, along with the other eye, remain active. In this way, the cranes can sleep, while literally keeping one eye open. As dawn arrives, we get our first glimpse of the number of cranes that arrived here last night. At the height of their migration in mid-March, there can be over 400,000 cranes on this stretch of river, making it the largest gathering of cranes anywhere in the world. As daylight improves, we can see there are both lesser and greater Sandhill Cranes here, but unless they're standing together, it's difficult to tell them apart. Greater Sandhill Cranes make up about 40% of this population, and are slightly larger in size. As the light continues to improve, the cranes become more restless. Spreading and flapping their wings, they jump, bow and dance, showing their readiness to begin the day. Then, at sunrise, they begin forming small flocks, as they head out to feed. Partially hidden by the Sandhill Cranes, in the back are three of the rarest birds in the world, Hooping Cranes. By the 1940s, it's believed their population had been reduced to less than 20 birds. Now protected, it's estimated their migratory population today is somewhere around 600. Together with the Sandhill Cranes, this family heads out to feed in the nearby fields. As morning continues, more and more cranes leave the river to feed. Some will forage in wet meadow or tall grass prairie, while others forage in the nearby cornfields, loading up on kernels left from last fall's harvest. For the next three to four weeks, they will spend most of their days here, gaining up to 25% in body weight, a requirement that will ensure they are in peak physical condition when they resume their northward journey. In the north, spring may not have fully arrived just yet, but it's been a long journey for this pair, who flew all this way for a reason. Wetlands and marshes are prime nesting habitat, and while some of it may still be frozen, it won't be long now until the sun begins to warm things up. Time to start checking out some potential nesting sites. But it looks like others may have beaten them to it. Still, there should be plenty of room for all. Cranes mate for life, and this is the time of year they reaffirm their bonds with each other. They do this through a fascinating and extensive system of calls and body language. Calling is also used to establish dominance and protect breeding territory. That is, after all, why they flew all this way. Although Sandhill cranes are naturally gray in color, they often rub mud on their feathers in a process known as staining. And where mud is found in an iron-rich environment, it stains their feathers a reddish brown. It's not fully understood why they do this, but some biologists think it may allow the cranes to blend in better with their surroundings, especially during nesting season. But first things first. This female is giving her mate the look. But he's seen that before and knows exactly how to respond. Wetlands are amongst the most threatened ecosystems in Canada, and in spring become very busy places. Wetlands make ideal habitat. They provide insects, amphibians and plant tubes to feed on, which in addition to replenishing calories lost during migration, also provide specific nutrients and proteins essential for reproduction. This pair have built a nest on a shallow island in this wetland using whatever plant material was at hand. But the nest is only a few centimeters above the water level and requires constant maintenance. The female has laid two eggs, and over the next few weeks, the parents will take turns incubating the eggs. Their babies are known as colts. And colts, born earlier in the spring, have slightly better odds of surviving their first year. So these parents will now have to endure a variety of spring weather. The male has been on the nest for several hours and now needs to feed. So he calls his mate. But she is nowhere to be seen. So he gently turns the eggs and does a little nest maintenance as he waits. Presently, she returns to the nest. And after a few final adjustments, he can now head off to feed. Within a few weeks, the wetlands are transformed. Along with all the new plant growth, there is also an abundance of new wildlife here too. The cranes have now abandoned their nesting island, and I wonder where they are. But soon I spot them. Although they laid two eggs, it looks like only one has hatched. This little one may only be a few centimeters tall, but just a few hours after hatching, he can already walk and swim. He will grow quickly, gaining as much as a half a kilo in body weight and growing up to two to three centimeters each day. It doesn't take long for him to begin looking more grown up. Since the beaks of young colts are not yet well suited to digging, his parents will help feed him. They're experts at digging and easily provide access to plenty of insects and vertebrates and roots for him to feed on. But when he's not eating, he needs to preen. His itchy down feathers are now being replaced with juvenile feathers. And since there are now so many growing in, it's almost a full-time job. It's tiring work for this little guy, and well, there's nothing like a good afternoon nap. Throughout the summer months, the young colt will continue to grow, gradually becoming more independent. And by the time fall arrives, he is almost fully grown. Now able to feed himself and fully capable of flight, he will soon accompany his parents on their long journey south, joining up with other families for the first time in his young life, where together they will teach him their ancient migration route. After spending winter in the south, they will return again next year. But as his parents ready themselves for another new family, their yearling will begin a new life on his own. It may take a few years, but eventually he too will find a mate. And this ancient life cycle of the Sandhill Cranes will begin all over again.