The pilot reported that he and his passenger were conducting a wildlife damage management flight in a heavily wooded area. He hovered the helicopter about 70 ft above ground level and coordinated with the passenger to locate the target. He then moved the helicopter aft and right for the passenger to have a better view of the target, when the helicopter shuddered and descended as the main and tail rotor blades collided with a tree. The pilot ascended out of the wooded area and located an open field for a precautionary landing, then landed without further incident. The helicopter sustained substantial damage to the main rotor blades and tail rotor blades. After landing, they walked back to the accident area and located one tree that was taller than the surrounding canopy and observed cut tree limbs on the ground beneath the tree. The pilot reported that there were no preimpact mechanical malfunctions or failures that would have precluded normal operation.