Hi Mike With 1/400 you are in the ballpark Do try making some at a newspaper and check the sharpness, vary the shutter speed and will see the results. It will help you improve the technique.
I guess you were tyring to select the bird to work on the bg? Can be done but its tricky, I'm sure we have a tutorial on selections and might give you some ideas. What I like best is that you know what to look for. Try setting up a feeder with a good bg !!! Give them food and they will show !!!!