This painting is taking me much longer than I imagined, which is good! I'm spending more time thinking about color choices before jumping in. Although I have a color comp, I still need to decide how to create the colors I want, and what shadow combinations will be suitable.
Here I have put in another layer of shadow in the foreground wings, and put the first layer down for color. The great horned owl's hood is going to be a rich brown, so I used a layer of yellow ochre as a base layer. Since the barred owl's cloak will be a rich green, I used cadmium yellow. I find layering watercolor creates a tone that blends better than putting down one simple layer of thick mixed color.
Again, I found myself in such concentration I went a long stretch without scanning! Lots of detail in the feathers at this point. For the great horned owl's wing, I created a mask with tracing paper around the entire painting except that wing, then used a toothbrush to splatter white gouache and payne's gray watercolor to get the speckled appearance that great horned owls have on their wings and back.
For the sky, I mixed color with white gouache to make the color more opaque. I find this works well when I want a very rich, smooth color. At this point, I also removed the masking fluid from the moon, and painted in the branches.