Under pressure from screwworm outbreaks, and from hunters equipped with repeating rifles, dogs, traps, pitfalls, snares and night lights, whitetailed deer population declined dramatically into the 1950s. However, with the advent of effective screwworm control, and the introduction of hunting seasons, bag limits, predator control, and cooperative management among landowners, deer numbers have boomed. Current concerns about deer center on the spread of chronic wasting disease, and the ethically and genetically-fraught problems of captive breeding and high-fence hunting operations.