Since 1988, NDA has worked to promote sustainable, high-quality deer populations, wildlife habitats and ethical hunting experiences through research, education, advocacy, and hunter recruitment. NDA teaches deer hunters how to improve local deer populations, habitat and hunting experiences.To enhance the fun and excitement of deer hunting, NDA encourages the protection of most or all yearling (1½-year-old) bucks combined with an appropriate harvest of does, when necessary, to maintain a healthy population in balance with habitat conditions and hunter desires.