Developing another crane painting

Original reference, cropped and "photoshopped", sized for an 18" x 36" canvas.

This one may be called "Taking Flight".  Another crane painting.  Ken took the shot at Bosque del Apache in the fall of 2013.  It's a gorgeous photo.  I pumped the color a bit, cropped it, sized it and re-arranged it a bit.  I drew the cranes one at a time, pulling them out of the photos (some were so jumbled up in one area that it was a little difficult to discern what they were doing, what attitude their wings were taking, which is what I was after.)  You can see my thumbnail in the previous post.  I also did a charcoal of the background, figuring out the values, before I did the following underpainting:

Underpainting done on canvas toned with yellow ochre.  I painted with burnt sienna and ultramarine.

Charcoal drawing of cranes, "to size", about 6" each, trying to capture each wing attitude.

I painted in the cranes using values of Ivory Black in 7 steps.  Now I will start on the "second statement" using local color. I will follow as closely as possible the values I have set out in this underpainting.