In March 2005, our friend Margery Nicolson led us on a pre-dawn hike to a
blind by the Platte River, in central Nebraska. The sound of roosting
Sandhill Cranes calling to each other grew slowly for an hour or more. Then,
one group of birds took decisively to the air. Within moments, thousands
joined them in a vast cloud, many passing directly over our heads.
You can tell the younger ones by their higher-pitched voices.
