Population Growth: Increase, over a specific period of time, in the number of individuals living in a country or region.Population Dynamics: The pattern of any process, or the interrelationship of phenomena, which affects growth or change within a population.Population Density: Number of individuals in a population relative to space.Population Control: Includes mechanisms or programs which control the numbers of individuals in a population of humans or animals.Urbanization: The process whereby a society changes from a rural to an urban way of life. It refers also to the gradual increase in the proportion of people living in urban areas.Ecosystem: A functional system which includes the organisms of a natural community together with their environment. (McGraw Hill Dictionary of Scientific and Technical Terms, 4th ed)Conservation of Natural Resources: The protection, preservation, restoration, and rational use of all resources in the total environment.Reproduction: The total process by which organisms produce offspring. (Stedman, 25th ed)Ecology: The branch of science concerned with the interrelationship of organisms and their ENVIRONMENT, especially as manifested by natural cycles and rhythms, community development and structure, interactions between different kinds of organisms, geographic distributions, and population alterations. (Webster's, 3d ed)Demography: Statistical interpretation and description of a population with reference to distribution, composition, or structure.Environment: The external elements and conditions which surround, influence, and affect the life and development of an organism or population.Esocidae: A family of freshwater fish of the order ESOCIFORMES, comprising the pikes, inhabiting the waters of the Northern Hemisphere. There is one genus, Esox, with five species: northern pike, grass pickerel, chain pickerel, muskellunge, and Amur pike.Life Cycle Stages: The continuous sequence of changes undergone by living organisms during the post-embryonic developmental process, such as metamorphosis in insects and amphibians. This includes the developmental stages of apicomplexans such as the malarial parasite, PLASMODIUM FALCIPARUM.Introduced Species: Non-native organisms brought into a region, habitat, or ECOSYSTEM by human activity.Organization and Administration: The planning and managing of programs, services, and resources.Climate Change: Any significant change in measures of climate (such as temperature, precipitation, or wind) lasting for an extended period (decades or longer). It may result from natural factors such as changes in the sun's intensity, natural processes within the climate system such as changes in ocean circulation, or human activities.Animal Nutrition Sciences: The study of NUTRITION PROCESSES, as well as the components of food, their actions, interaction, and balance in relation to health and disease in animals.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Fertility: The capacity to conceive or to induce conception. It may refer to either the male or female.Population: The total number of individuals inhabiting a particular region or area.Food Chain: The sequence of transfers of matter and energy from organism to organism in the form of FOOD. Food chains intertwine locally into a food web because most organisms consume more than one type of animal or plant. PLANTS, which convert SOLAR ENERGY to food by PHOTOSYNTHESIS, are the primary food source. In a predator chain, a plant-eating animal is eaten by a larger animal. In a parasite chain, a smaller organism consumes part of a larger host and may itself be parasitized by smaller organisms. In a saprophytic chain, microorganisms live on dead organic matter.Mechanics: The branch of physics which deals with the motions of material bodies, including kinematics, dynamics, and statics. When the laws of mechanics are applied to living structures, as to the locomotor system, it is referred to as BIOMECHANICAL PHENOMENA. (From Dorland, 28th ed)Primula: A plant genus of the family PRIMULACEAE. It can cause CONTACT DERMATITIS. SAPONINS have been identified in the root.Genetics, Population: The discipline studying genetic composition of populations and effects of factors such as GENETIC SELECTION, population size, MUTATION, migration, and GENETIC DRIFT on the frequencies of various GENOTYPES and PHENOTYPES using a variety of GENETIC TECHNIQUES.Human Activities: Activities performed by humans.Climate: The longterm manifestations of WEATHER. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Daphnia: A diverse genus of minute freshwater CRUSTACEA, of the suborder CLADOCERA. They are a major food source for both young and adult freshwater fish.Estuaries: A partially enclosed body of water, and its surrounding coastal habitats, where saltwater from the ocean mixes with fresh water from rivers or streams. The resulting mixture of seawater and fresh water is called brackish water and its salinity can range from 0.5 to 35 ppt. (accessed http://oceanservice.noaa.gov/education/kits/estuaries/estuaries01_whatis.html)Economic Development: Mobilization of human, financial, capital, physical and or natural resources to generate goods and services.Models, Statistical: Statistical formulations or analyses which, when applied to data and found to fit the data, are then used to verify the assumptions and parameters used in the analysis. Examples of statistical models are the linear model, binomial model, polynomial model, two-parameter model, etc.Birth Rate: The number of births in a given population per year or other unit of time.Geography: The science dealing with the earth and its life, especially the description of land, sea, and air and the distribution of plant and animal life, including humanity and human industries with reference to the mutual relations of these elements. (From Webster, 3d ed)Biological Evolution: The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.Birds: Warm-blooded VERTEBRATES possessing FEATHERS and belonging to the class Aves.United Nations: An international organization whose members include most of the sovereign nations of the world with headquarters in New York City. The primary objectives of the organization are to maintain peace and security and to achieve international cooperation in solving international economic, social, cultural, or humanitarian problems.Family Planning Services: Health care programs or services designed to assist individuals in the planning of family size. Various methods of CONTRACEPTION can be used to control the number and timing of childbirths.History, Ancient: The period of history before 500 of the common era.Models, Theoretical: Theoretical representations that simulate the behavior or activity of systems, processes, or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.Stramenopiles: A common name (but used formally) for a group of organisms that are mostly kinds of algae including BACILLARIOPHYTA; OOMYCETES; PHAEOPHYCEAE; and CHRYSOPHYCEAE. They all contain CHLOROPLASTS that are thought to have been derived from the endosymbiosis of ancient RED ALGAE.Agriculture: The science, art or practice of cultivating soil, producing crops, and raising livestock.Predatory Behavior: Instinctual behavior pattern in which food is obtained by killing and consuming other species.Canidae: A family of terrestrial carnivores with long snouts and non-retractable claws. Members include COYOTES; DOGS; FOXES; JACKALS; RACCOON DOGS; and WOLVES.Forecasting: The prediction or projection of the nature of future problems or existing conditions based upon the extrapolation or interpretation of existing scientific data or by the application of scientific methodology.Animal Distribution: A process by which animals in various forms and stages of development are physically distributed through time and space.Herbivory: The act of feeding on plants by animals.Radiometric Dating: Techniques used to determine the age of materials, based on the content and half-lives of the RADIOACTIVE ISOTOPES they contain.Genetic Fitness: The capability of an organism to survive and reproduce. The phenotypic expression of the genotype in a particular environment determines how genetically fit an organism will be.Stochastic Processes: Processes that incorporate some element of randomness, used particularly to refer to a time series of random variables.Genetic Variation: Genotypic differences observed among individuals in a population.Wolves: Any of several large carnivorous mammals of the family CANIDAE that usually hunt in packs.Cladocera: A suborder of CRUSTACEA, order Diplostraca, comprising the water fleas. They are benthic filter feeders that consume PHYTOPLANKTON. The body is laterally compressed and enclosed in a bivalved carapace, from which the head extends.Selection, Genetic: Differential and non-random reproduction of different genotypes, operating to alter the gene frequencies within a population.Strigiformes: An order of BIRDS with the common name owls characterized by strongly hooked beaks, sharp talons, large heads, forward facing eyes, and facial disks. While considered nocturnal RAPTORS, some owls do hunt by day.Models, Genetic: Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.Food Supply: The production and movement of food items from point of origin to use or consumption.Aphids: A family (Aphididae) of small insects, in the suborder Sternorrhyncha, that suck the juices of plants. Important genera include Schizaphis and Myzus. The latter is known to carry more than 100 virus diseases between plants.Platyhelminths: A phylum of acoelomate, bilaterally symmetrical flatworms, without a definite anus. It includes three classes: Cestoda, Turbellaria, and Trematoda.Fisheries: Places for cultivation and harvesting of fish, particularly in sea waters. (from McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)East Timor: A country in Southeastern Asia, northwest of Australia in the Lesser Sunda Islands at the eastern end of the Indonesian archipelago. It includes the eastern half of the island of Timor, the Oecussi (Ambeno) region on the northwest portion of the island of Timor, and the islands of Pulau Atauro and Pulau Jaco. On May 20, 2002, East Timor was internationally recognized as an independent state. This followed its declared independence from Portugal on November 20, 1975 and a period of armed conflict with Indonesia.WyomingPasseriformes: A widely distributed order of perching BIRDS, including more than half of all bird species.Atlantic OceanArchaeology: The scientific study of past societies through artifacts, fossils, etc.Cities: A large or important municipality of a country, usually a major metropolitan center.Body Size: The physical measurements of a body.Sea Lions: A group comprised of several species of aquatic carnivores in different genera, in the family Otariidae. In comparison to FUR SEALS, they have shorter, less dense hair.Toxicology: The science concerned with the detection, chemical composition, and biological action of toxic substances or poisons and the treatment and prevention of toxic manifestations.Hemiptera: A large order of insects characterized by having the mouth parts adapted to piercing or sucking. It is comprised of four suborders: HETEROPTERA, Auchenorrhyncha, Sternorrhyncha, and Coleorrhyncha.Economics: The science of utilization, distribution, and consumption of services and materials.Arvicolinae: A subfamily of MURIDAE found nearly world-wide and consisting of about 20 genera. Voles, lemmings, and muskrats are members.Trees: Woody, usually tall, perennial higher plants (Angiosperms, Gymnosperms, and some Pterophyta) having usually a main stem and numerous branches.Sex Ratio: The number of males per 100 females.Species Specificity: The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.Africa, Eastern: The geographical area of Africa comprising BURUNDI; DJIBOUTI; ETHIOPIA; KENYA; RWANDA; SOMALIA; SUDAN; TANZANIA; and UGANDA.Health Manpower: The availability of HEALTH PERSONNEL. It includes the demand and recruitment of both professional and allied health personnel, their present and future supply and distribution, and their assignment and utilization.Genetic Drift: The fluctuation of the ALLELE FREQUENCY from one generation to the next.Endangered Species: An animal or plant species in danger of extinction. Causes can include human activity, changing climate, or change in predator/prey ratios.Seasons: Divisions of the year according to some regularly recurrent phenomena usually astronomical or climatic. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)DNA, Mitochondrial: Double-stranded DNA of MITOCHONDRIA. In eukaryotes, the mitochondrial GENOME is circular and codes for ribosomal RNAs, transfer RNAs, and about 10 proteins.Butterflies: Slender-bodies diurnal insects having large, broad wings often strikingly colored and patterned.Weather: The state of the ATMOSPHERE over minutes to months.Far East: A geographic area of east and southeast Asia encompassing CHINA; HONG KONG; JAPAN; KOREA; MACAO; MONGOLIA; and TAIWAN.Computer Simulation: Computer-based representation of physical systems and phenomena such as chemical processes.Beetles: INSECTS of the order Coleoptera, containing over 350,000 species in 150 families. They possess hard bodies and their mouthparts are adapted for chewing.Animal Migration: Periodic movements of animals in response to seasonal changes or reproductive instinct. Hormonal changes are the trigger in at least some animals. Most migrations are made for reasons of climatic change, feeding, or breeding.Extinction, Biological: The ceasing of existence of a species or taxonomic groups of organisms.Rain: Water particles that fall from the ATMOSPHERE.Deer: The family Cervidae of 17 genera and 45 species occurring nearly throughout North America, South America, and Eurasia, on most associated continental islands, and in northern Africa. Wild populations of deer have been established through introduction by people in Cuba, New Guinea, Australia, New Zealand, and other places where the family does not naturally occur. They are slim, long-legged and best characterized by the presence of antlers. Their habitat is forests, swamps, brush country, deserts, and arctic tundra. They are usually good swimmers; some migrate seasonally. (Walker's Mammals of the World, 5th ed, p1362)