Summer’s great crescendo
As the excitement fades from the return of trumpeter swans, we turn our eyes to the skies along the Tintina Trench, to watch for sandhill cranes. Trumpeter swans might kick off our birding season, but the sandhill cranes are the great crescendo heading into summer. Flocks of hundreds will darken the skies above Faro this spring, as they have for thousands of years.
Sandhill cranes are members of the Gruiformes order. They share this group with whooping cranes, five subspecies of sandhill crane, the American coot and the sora. They have grey bodies and white cheeks, with a jaunty red cap on their foreheads. They stand about one metre tall and, like trumpeter swans, have a two-metre wingspan. But unlike the ten-kilogram swans, sandhill cranes only weigh about three kilograms.
Like most large birds, sandhill cranes mate for life and are known for their elaborate mating dances and rituals. They’re revered in many cultures for their fidelity and the devotion of both parents to raising their young. The groups migrating overhead are families returning to their nesting grounds before the parents say goodbye to their young and start raising a new brood.
Sandhill cranes are the most numerous of all cranes in the world. Their adaptability to new environments and food versatility has allowed them to weather many changes across the landscape. They’ll eat anything, from seeds and berries to frogs and fish, even rodents, insects and plants. They’re considered a grassland bird as opposed to a wetland bird, and male cranes are called “stallions”; female cranes are “mares,” and baby cranes are “colts.”
Though they look like other long-legged wading birds, such as herons or storks, they’re not closely related at all. Cranes and herons are examples of convergent evolution: they have different ancestors but have evolved over millions of years to look similar and fill similar niches.
Towns like Faro will see about 150,000 to 200,000 cranes fly over every year. The birds are coming up from their wintering grounds in the sandhills of Texas, New Mexico and Northern Mexico. Along the way, they’ll stop in staging areas such as Platte River, Nebraska, to rest and feed (like Swan Haven for trumpeter swans).
When they reach the Yukon, they’ll follow the Tintina Trench, a geological fault line where two terranes meet and that carves a 725-kilometre-long diagonal line from Watson Lake, up to Faro and over to Alaska. They’re racing to their nesting grounds in Central Yukon and Alaska, where they return year after year.
Sandhill cranes have the longest migration of any crane in the world, with some making a 22,500-kilometre round trip. Some will go as far as the North Slope and even over to Siberia. They can travel as far as 800 kilometres in a day by using a technique called “kettling” (think: steam rising from a kettle). The sun heats the Earth’s crust and warm air rises.
The cranes find these patches of warm air, called thermals, and ride the rising air to gain altitude without a lot of effort. To the observer, it looks like a flock of cranes has suddenly gotten confused and is flying around in circles. Once high enough, they’ll stretch out again into a giant V, to soar with minimal wing flaps, gradually losing altitude until they find the next thermal.
You can witness this truly amazing spectacle of nature in the Yukon during the first two weeks of May. The Town of Faro has been hosting a festival on the first weekend of May for more than 20 years, to celebrate the return of the cranes. Take a trip to Faro this spring to see hundreds of thousands of sandhill cranes fly over.
