You need a Federal Migratory Game Bird Harvest Information Program, or Federal HIP, validation on your hunting license. It's not really a stamp. It costs $1.50, which pays the license vendor for issuing the validation. It is required for hunting doves, sandhill cranes, snipe and all waterfowl. With the information gained when hunters answer a questionnaire each year when buying the Federal HIP, the U.S. Fish and Wildlife Service can do a more accurate job of managing these migratory birds.