The bird you are going to hit is outside your cockpit windows, not inside it. Use your eyes. See and avoid. By the time you see something on your radar and decide that the pattern you see is a bird flock, and then determine based on your tilt and gain settings where said flock is located relative to your position and altitude, and then LOOK OUTSIDE to visually identify the birds and take evasive action, you have already hit them or missed them.
ATC can sometimes see flocks of birds on their radar scopes, and give advisory info ("possible flock of birds crossing the final at 3 DME"). It is useful, and to me it is the max extent that Radar is capable of being helpful in identifying birds.