The flight instructor and the student pilot began preparing for arrival at the destination airport at the conclusion of an instructional flight. While cruising at an altitude of 1,600 feet, they turned the airplane north, and noticed three buzzards that were ahead, below, and to the right of their airplane and climbing. The pilots disconnected the autopilot and entered a climbing left turn in an attempt to avoid the group of birds. After avoiding two of the birds, the remaining bird suddenly changed direction and impacted the right wing, resulting in substantial damage to its composite structure. After advising air traffic control of the encounter, the pilots landed the airplane uneventfully at a nearby airport.