1.Using kitchen scissors cut along both sides of chickens’ backbones; discard backbones. Place chickens, skin-side up, on board; press down on breastbones to flatten. Using fingertips, carefully ease skin away from chicken breasts and thighs (don’t pull it off).
2.Combine anchovy, rind, capers and butter in small bowl; season.
3.Push half the butter mixture under chicken skins. Melt remaining butter; brush all over chickens.
4.Heat covered barbecue. Cook chickens, skin-side down, on barbecue, using direct heat, until browned lightly. Turn chickens, sprinkle with half the rosemary; cook, covered, using indirect heat, following manufacturer’s instructions, about 25 minutes. Serve sprinkled with remaining rosemary.