A mechanism for producing simulated tail motion or other motion in a waterfowl decoy. It may include a cantilevered carbon fiber composite spring clamped rigidly at one end and free at the other. At the free distal end of the spring, a permanent magnet and simulated tail are affixed. Fixed rigidly nearby, within the decoy body, near the magnet but not in direct contact with the magnet, is an inductor/coil. The coil is energized and de-energized at a frequency matching the resonant frequency of the spring/magnet/tail assembly, which causes the tail/magnet assembly to oscillate back and forth from side to side as the magnetic field within the coil varies, providing variable attraction between coil and magnet. Custom circuitry, which is energized by a battery, provides appropriately timed electrical impulses to the coil.
