Related by context. Frequent words. (Click for all words.) 72 populations 53 Population 52 species 51 population 51 amphibian populations 50 Endangered 50 Mortality 50 Species 49 grassland birds 49 Critically Endangered 49 Endemic 49 Migratory 48 Prevalence 48 subpopulations 48 Economies 48 breeding colonies 48 Diseases 47 Diagnoses 47 mammal species 47 Sage grouse 46 Harvests 46 migratory species 46 Salamanders 46 birthrates 46 Epidemics 46 subspecies 46 deer herds 45 Incidence 45 Mammals 45 amphibian species 45 temperate forests 45 Overfishing 45 terrestrial ecosystems 45 Infestations 45 Concentrations 45 mammals 44 Habitats 44 Infections 44 Study Examines 44 Cyanobacteria 44 crocodilians 44 insect populations 44 Coral Reefs 44 Bald eagles 44 Susceptibility 44 avian species 44 breeding pairs 44 Males 43 Inequalities 43 penguin species 43 vertebrate species 43 Extinct 43 habitats 43 damselflies 43 Pathogens 43 Tumors 43 genetic variability 43 temperate regions 43 Walruses 42 Life Expectancy 42 caribou herds 42 bee populations 42 Tumours 42 POPULATION 42 habitat fragmentation 42 rookeries 42 nesting pairs 42 Chronic Diseases 42 waterbirds 42 Parasitic 42 temperate zones 42 Microorganisms 42 Gypsy moths 42 threadfin shad 42 tiger mosquito 42 subpopulation 42 Amphibians 42 overhunting 42 Countries 42 freshwater ecosystems 42 coral species 42 Steller sea lions 42 Life expectancy 41 Urbanization 41 grebe 41 bird species 41 Aphids 41 Orangutans 41 apex predators 41 Breast Cancer Risk 41 Biologically 41 honeybee colonies 41 taxa 41 pronghorns 41 Disease 41 Parasites 41 wolf populations 41 breeding colony 41 clouded leopards 41 Intermarriage 41 mortality