Our day started at 5:30 am in the cold darkness as we waited for the dawn light to photograph the high altitude San Luis Valley full of 20,000 or more Sandhill Cranes.

When the sun finally rose over the mountains it lit up the valley covered in a fresh blanket of bright white snow.  The light was bright.  Light bounced off the valley floor and underlit the undersides of flying birds so much that they looked white.

During March and April, this huge valley fills with Sandhill Cranes.  The cranes stopover on their migration from their wintering grounds to the south, like the Bosque del Apache National Wildlife Refuge.  During their stay in the San Luis Valley, they reinforce their lifelong pair bonding through an elegant dance.  The number of cranes this year was phenomenal.  Estimates of 20,000 cranes were present.  Huge flocks of Canada Geese and Northern Pintails shared the frozen fields with the cranes.

The day warmed up to a balmy 14 deg F.  Golden Eagles, Bald Eagles, Red-tailed Hawks, Peregrine Falcons, and Prairie Falcons intermittently soared above preying on the masses of waterfowl.  Normally when an eagle appeared the valley floor erupted with thousands of birds taking off.  The sounds of thousands of wings flapping accompanied by the warning calls of cranes, geese, and ducks were ominous.

On this chilly day, the cranes seemed to be less wary when an eagle was present, although every bird in the valley seems to know when an eagle shows up.

Below, I show a harrowing sequence of photos as a Golden Eagle dives on a duck.