Related by context. Frequent words. (Click for all words.) 58 yellow legged frogs 57 species 57 functionally extinct 57 amphibian populations 57 Adelie penguins 57 amphibian species 56 vertebrate species 56 aquatic invertebrates 55 mammal species 55 Sumatran orangutans 54 plesiosaurs 54 Steller sea lion 54 baiji 54 Biological Conservation 54 Sea otters 53 Irrawaddy dolphins 53 toothed whales 53 frogs toads 53 amphipods 53 quaggas 53 mammals 53 frog species 53 amphibians 52 eiders 52 Sumatran rhinos 52 lowland gorillas 52 bird species 52 Sperm whales 52 endangered mammal 52 marbled murrelets 52 pupfish 52 petrels 52 avian species 52 emperor penguin 51 Mule deer 51 marine invertebrates 51 freshwater mussels 51 penguin species 51 guillemots 51 threatened delta smelt 51 Florida panthers 51 leatherback turtles 51 yellow legged frog 51 temperate forests 51 golden plover 51 mountain glaciers 51 northern spotted owls 51 Amur leopard 51 leatherback turtle 50 overfishing pollution 50 Cook Inlet belugas 50 penguin colonies 50 pine marten 50 Colossal squid 50 shovelnose 50 wintering birds 50 leatherback 50 mammal 50 horned dinosaurs 50 Javan rhinos 50 placental mammals 50 Sage grouse 50 beluga sturgeon 50 marine reptiles 50 grassland birds 50 beaked whale 50 Ecology Letters 50 kittiwakes 50 seagrasses 50 wood stork 50 waterbird 50 glacial retreat 50 caribou herds 50 Sumatran elephants 50 damselfish 50 damselflies 49 critically endangered 49 seahorses 49 Humpback whale 49 sea otters 49 basking sharks 49 spoonbills 49 murrelet 49 godwits 49 narwhal 49 terrestrial ecosystems 49 biodiversity hotspots 49 wetland ecosystems 49 marine iguanas 49 Hector dolphins 49 Arctic foxes 49 marten 49 federally endangered species 49 reproduce asexually 49 endemism 48 waterbirds 48 Yellowstone cutthroat trout 48 saiga 48 Alpine glaciers 48 freshwater 48 sticklebacks