Birds 41 Birds, Protection of 8 BIRDS 6 Control 5 Ornithology 5 BIRDS IN ART 4 Mammals 4 NATURAL HISTORY 4 Physiology 4 Pictorial works 4 Vertebrate pests 4 Bird pests 3 Birds in art 3 Birds of prey 3 Conservation 3 Equipment and supplies 3 Pesticides and wildlife 3 Testing 3 Aircraft bird strikes 2 Behavior 2 Bird baits and repellents 2 Bird banding 2 Bird populations 2 Bird watching 2 Bromomethane 2 Flight 2 Fumigants 2 Game and game-birds 2 Geographical distribution 2 Habitat 2