After completely drying the painting with a hair dryer, I have now added a little under-painting for the branch the bird is resting on.
I used a mixture of Burnt Sienna and VanDyke Brown. Only progressing a short distance at a time, I draw some pigment, a relatively dense blend of pigment, just a little water, along the left edge of the branch. I only go about one or two inches, then I quickly rinse my brush, touch it to a cloth or paper towel so that it is wet, but not dripping. With the moist brush, I pull along the edge of the color that I just applied, pulling the water into the wash, not pulling the wash out. This technique softens the right edge of the wash without diluting too much color and without creating a strange edge where the water is applied. Be sure your water is clean and that you do not brush more than one stroke.
I continue with this method along the wooden branch, just a little at a time. If I apply the coat of color too far down the branch, it may dry out before I come back with the water.
Once the entire branch edge is applied with this technique, I can go back and touch in a little more color here and there, being sure to soften edges to keep this under-painting as simply a foundation for details to come.