Why a shuttlecock is called a birdie — because traditional feather shuttles are made from real goose or duck feathers, 16 of them by BWF rule, fixed into a cork base about 25–28 mm wide. The name 'shuttle' comes from the Old English weaving tool; 'cock' from the feathered tail-like shape. The casual American nickname 'birdie' stuck because the projectile is literally a small bird-feather assembly. Verified specs included, plus the manual feather-tying that still happens by hand.