This time of year, the passing squadrons of migrating sand-hill cranes wheel and veer over my casa near the Rio Grande, which is their flight-way. They're heading today toward a wet and watery refuge 100 miles south, at Bosque del Apache.
Their cries fill the sky, but they're tricky to spot, because their undersides are pale and, at the altitudes where they fly, their slim silhouettes don't stand out against that azure sky.
Their cries are unmistakable. They're there, but you look where the sound says they should be and there's nothing there. But then in a shimmer, the flock wheels and changes course and as they bank and swoop, they appear.
Even at the distance--they're at least 700-1000 feet in the air, and often at a remove of many hundreds of meters in lateral distance--the effect can be mesmerizing.
I invariably stop to try to spot the flocks when I hear them, when I'm out walking a dog on the ditch.
Twice a year, late autumn and middle spring...
For now, at least.