Endangered species 82 Juvenile literature 32 Wildlife conservation 21 Identification 14 Pictorial works 13 Extinct animals 11 Rare animals 10 Forests and forestry 8 Birds 7 Trees 7 Orchids 6 Conservation 5 Wildlife refuges 5 Animals 4 Braille books 4 Dissertations 4 Dissertations, Academic 4 Elephants 4 Endandered species 4 Insects 4 Endangered plants 3 Fishes 3 Herbs 3 Mammals 3 Miscellanea 3 Varieties 3 Acacia 2 Asiatic elephant 2 Bats 2 Breeding 2