AFRICAN BLACK DUCK (Anas sparsa) is a favorite. Probably because they don’t come easy. Have shot them over decoys but rarely. These mallard-like “river ducks” territorially defend short stretches of narrow, serpentine rivers they call home. Finding them usually requires putting on the boot-leather miles under hot sun where, laying motionless, they’ll oftentimes let you walk past undetected. This handsome pair was among only 5 collected during a 2-year period for critical genetics research conduc