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The Ideal Free Distribution
In ecology, an ideal free distribution (IFD) is a theoretical way in which a populations individuals distribute themselves among several patches of resources within their environment, in order to minimize resource competition and maximize fitness.Fretwell, S. D. 1972. ''Populations in a Seasonal Environment''. Princeton, NJ: Princeton University Press.Fretwell, S. D. & Lucas, H. L., Jr. 1970. On territorial behavior and other factors influencing habitat distribution in birds. I. Theoretical Development. ''Acta Biotheoretica'' 19: 16–36. The theory states that the number of individual animals that will aggregate in various patches is proportional to the amount of resources available in each. For example, if patch A contains twice as many resources as patch B, there will be twice as many individuals foraging in patch A as in patch B. The term "ideal" implies that animals are aware of each patch's quality, and they choose to forage in the patch with the highest quality. The term ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecology
Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overlaps with the closely related sciences of biogeography, evolutionary biology, genetics, ethology, and natural history. Ecology is a branch of biology, and it is not synonymous with environmentalism. Among other things, ecology is the study of: * The abundance, biomass, and distribution of organisms in the context of the environment * Life processes, antifragility, interactions, and adaptations * The movement of materials and energy through living communities * The successional development of ecosystems * Cooperation, competition, and predation within and between species * Patterns of biodiversity and its effect on ecosystem processes Ecology has practical applications in conservation biology, wetland management, natural resource managemen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oikos (journal)
''Oikos'' is a monthly peer-reviewed scientific journal covering research in the field of ecology. It is published by Wiley-Blackwell on behalf of the Nordic Foundation Oikos. Since 2011, the editor-in-chief has been Dries Bonte of Ghent University. History The journal was established in 1949 as ''Oikos: Acta Oecologica Scandinavica'', together with the Nordic Foundation Oikos, to provide a vehicle for publishing in the growing field of ecology. The journal content would have no preference with regard to taxonomic group. In the 1970s the scope was narrowed to studies with relevance to the progress of theory in ecology. From 1949 to 1977, the journal appeared in one volume of three issues per year. From 1977 to 1987, two volumes per year were produced, and three volumes from 1987. In addition, from 1949–1975, a number of supplements were published at irregular intervals. Since 2007, the ''Oikos'' subject editors make nominations for the annual Per Brinck Oikos Award given to a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optimal Foraging Theory
Optimal foraging theory (OFT) is a behavioral ecology model that helps predict how an animal behaves when searching for food. Although obtaining food provides the animal with energy, searching for and capturing the food require both energy and time. To maximize fitness, an animal adopts a foraging strategy that provides the most benefit (energy) for the lowest cost, maximizing the net energy gained. OFT helps predict the best strategy that an animal can use to achieve this goal. OFT is an ecological application of the optimality model. This theory assumes that the most economically advantageous foraging pattern will be selected for in a species through natural selection. When using OFT to model foraging behavior, organisms are said to be maximizing a variable known as the currency, such as the most food per unit time. In addition, the constraints of the environment are other variables that must be considered. Constraints are defined as factors that can limit the forager's abili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marginal Value Theorem
The marginal value theorem (MVT) is an optimality model that usually describes the behavior of an optimally foraging individual in a system where resources (often food) are located in discrete patches separated by areas with no resources. Due to the resource-free space, animals must spend time traveling between patches. The MVT can also be applied to other situations in which organisms face diminishing returns. The MVT was first proposed by Eric Charnov in 1976. In his original formulation: "The predator should leave the patch it is presently in when the marginal capture rate in the patch drops to the average capture rate for the habitat." Charnov, E. L. 1976. Optimal foraging: the marginal value theorem. Theoretical Population Biology 9:129–136 Definition All animals must forage for food in order to meet their energetic needs, but doing so is energetically costly. It is assumed that evolution by natural selection results in animals utilizing the most economic and efficient strat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Behavioural Ecology
Behavioral ecology, also spelled behavioural ecology, is the study of the evolutionary basis for animal behavior due to ecological pressures. Behavioral ecology emerged from ethology after Niko Tinbergen outlined four questions to address when studying animal behaviors: What are the proximate causes, ontogeny, survival value, and phylogeny of a behavior? If an organism has a trait that provides a selective advantage (i.e., has adaptive significance) in its environment, then natural selection favors it. Adaptive significance refers to the expression of a trait that affects fitness, measured by an individual's reproductive success. Adaptive traits are those that produce more copies of the individual's genes in future generations. Maladaptive traits are those that leave fewer. For example, if a bird that can call more loudly attracts more mates, then a loud call is an adaptive trait for that species because a louder bird mates more frequently than less loud birds—thus sending mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Matching Law
In operant conditioning, the matching law is a quantitative relationship that holds between the relative rates of response and the relative rates of reinforcement in concurrent schedules of reinforcement. For example, if two response alternatives A and B are offered to an organism, the ratio of response rates to A and B equals the ratio of reinforcements yielded by each response.Poling, A., Edwards, T. L., Weeden, M., & Foster, T. (2011). The matching law. ''Psychological Record'', 61(2), 313-322. This law applies fairly well when non-human subjects are exposed to concurrent variable interval schedules (but see below); its applicability in other situations is less clear, depending on the assumptions made and the details of the experimental situation. The generality of applicability of the matching law is subject of current debate. The matching law can be applied to situations involving a single response maintained by a single schedule of reinforcement if one assumes that alternativ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cichlid Fish
Cichlids are fish from the family Cichlidae in the order Cichliformes. Cichlids were traditionally classed in a suborder, the Labroidei, along with the wrasses ( Labridae), in the order Perciformes, but molecular studies have contradicted this grouping. The closest living relative of cichlids is probably the convict blenny, and both families are classified in the 5th edition of ''Fishes of the World'' as the two families in the Cichliformes, part of the subseries Ovalentaria. This family is both large and diverse. At least 1,650 species have been scientifically described, making it one of the largest vertebrate families. New species are discovered annually, and many species remain undescribed. The actual number of species is therefore unknown, with estimates varying between 2,000 and 3,000. Many cichlids, particularly tilapia, are important food fishes, while others, such as the ''Cichla'' species, are valued game fish. The family also includes many popular freshwater aquariu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daphnia
''Daphnia'' is a genus of small planktonic crustaceans, in length. ''Daphnia'' are members of the order Anomopoda, and are one of the several small aquatic crustaceans commonly called water fleas because their saltatory swimming style resembles the movements of fleas. ''Daphnia'' spp. live in various aquatic environments ranging from acidic swamps to freshwater lakes and ponds. The two most commonly found species of ''Daphnia'' are '' D. pulex'' (small and most common) and '' D. magna'' (large). They are often associated with a related genus in the order Cladocera: ''Moina'', which is in the Moinidae family instead of the Daphniidae, and is much smaller than ''D. pulex'' (roughly half the maximum length). Appearance and characteristics The body of a ''Daphnia'' species is usually long, and is divided into segments, although this division is not visible. The head is fused, and is generally bent down towards the body with a visible notch separating the two. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Positive Reinforcement
In behavioral psychology, reinforcement is a consequence applied that will strengthen an organism's future behavior whenever that behavior is preceded by a specific antecedent stimulus. This strengthening effect may be measured as a higher frequency of behavior (e.g., pulling a lever more frequently), longer duration (e.g., pulling a lever for longer periods of time), greater magnitude (e.g., pulling a lever with greater force), or shorter latency (e.g., pulling a lever more quickly following the antecedent stimulus). The model of self-regulation has three main aspects of human behavior, which are self-awareness, self-reflection, and self-regulation. Reinforcements traditionally align with self-regulation. The behavior can be influenced by the consequence but behavior also needs antecedents. There are four types of reinforcement: positive reinforcement, negative reinforcement, extinction, and punishment. Positive reinforcement is the application of a positive reinforcer. Negati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Matching Law
In operant conditioning, the matching law is a quantitative relationship that holds between the relative rates of response and the relative rates of reinforcement in concurrent schedules of reinforcement. For example, if two response alternatives A and B are offered to an organism, the ratio of response rates to A and B equals the ratio of reinforcements yielded by each response.Poling, A., Edwards, T. L., Weeden, M., & Foster, T. (2011). The matching law. ''Psychological Record'', 61(2), 313-322. This law applies fairly well when non-human subjects are exposed to concurrent variable interval schedules (but see below); its applicability in other situations is less clear, depending on the assumptions made and the details of the experimental situation. The generality of applicability of the matching law is subject of current debate. The matching law can be applied to situations involving a single response maintained by a single schedule of reinforcement if one assumes that alternativ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Populus Angustifolia
''Populus angustifolia'', commonly known as the narrowleaf cottonwood, is a species of tree in the willow family (Salicaceae). It is native to western North America, where it is a characteristic species of the Rocky Mountains and the surrounding plains.''Populus angustifolia'' Flora of North America It ranges north to the provinces of and in and south to the states of [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sugarbeet Root Aphid
''Pemphigus betae'', also known as the sugarbeet root aphid, is a species of gall-forming aphid that forms galls specifically on the commonly found narrowleaf cottonwood (aka the willow-leaved poplar tree), ''Populus angustifolia''. Sugarbeet root aphids have been found in North America and Europe. They infect sugarbeets, but also other plants like tablebeets and Swiss chard. Their size has been likened to that of a pinhead, and are pale white-yellow in color. Sugarbeet root aphids have soft bodies that are bulbous in shape, with mandibular parts that can pierce and suck and paired abdominal tubes that point backwards, and come in both winged and wingless forms. They are known for their consequential effects on agriculture due to infestation of plants, and efforts to control the pests have proved to be difficult. Description Sugarbeet root aphids have a body length of . They are characterized to be as small as pinheads, and take on a pale white-yellow color. They have globula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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