I have added another wet-in-wet wash at the base of the background at this stage. I used Hooker's Green and Perylene Green. I didn't want to have the feeling that the bird was floating too much. However, the background really is secondary to what is happening with the focal point of the bird.
To accomplish this wash I added a light, wet wash of Hooker's Green. Then I charged in darker, richer values of the colors I wanted. As they float in the edges are soft and muted, so they are down-played and they don't take away from the crisp detail of the bird.
To keep the edge of this wash very soft, I used a little clean water. The clear water is applied away from the wash and pulled into the wash. This keeps the color moving INTO the wash instead of continuing to pull color out and creating a funny line at the end of the water.