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Resource Defense Polygyny
In animal behavior, resource defense polygyny is a mating strategy where a male is able to support multiple female mates by competing with other males for access to a resource. In such a system, males are territorial. Because male movement is restricted, female-female competition for a male also results. Males capable of maintaining a larger territory are said to have greater resource holding power. It is one of the three major types of polygyny, the other two being female defense polygyny and leks. Examples Resource defense polygyny is a common strategy in insects. For examples, damselflies in the family Calopterygidae typically display resource defense polygyny, in which territorial males guard riverine habitat that is sought after by females for egg deposition. Within a species there may be a territorial and nonterritorial morph.{{Cite book , last1=Thornhill , first1=Randy , url=https://www.degruyter.com/document/doi/10.4159/harvard.9780674433960/html , title=The Evolution of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethology
Ethology is the scientific study of animal behaviour, usually with a focus on behaviour under natural conditions, and viewing behaviour as an evolutionarily adaptive trait. Behaviourism as a term also describes the scientific and objective study of animal behaviour, usually referring to measured responses to stimuli or to trained behavioural responses in a laboratory context, without a particular emphasis on evolutionary adaptivity. Throughout history, different naturalists have studied aspects of animal behaviour. Ethology has its scientific roots in the work of Charles Darwin and of American and German ornithologists of the late 19th and early 20th century, including Charles O. Whitman, Oskar Heinroth, and Wallace Craig. The modern discipline of ethology is generally considered to have begun during the 1930s with the work of Dutch biologist Nikolaas Tinbergen and Austrian biologists Konrad Lorenz and Karl von Frisch, the three recipients of the 1973 Nobel Prize in Phys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mating System
A mating system is a way in which a group is structured in relation to sexual behaviour. The precise meaning depends upon the context. With respect to animals, the term describes which males and females mating, mate under which circumstances. Recognised systems include monogamy, polygamy (which includes polygyny, polyandry, and polygynandry), and promiscuity, all of which lead to different mate choice outcomes and thus these systems affect how sexual selection works in the species which practice them. In plants, the term refers to the degree and circumstances of outcrossing. In human sociobiology, the terms have been extended to encompass the formation of relationships such as marriage. In plants The primary mating systems in plants are outcrossing (cross-fertilisation), autogamy (self-fertilisation) and apomixis (asexual reproduction without fertilization, but only when arising by modification of sexual function). Mixed mating systems, in which plants use two or even all three ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Selection
Sexual selection is a mode of natural selection in which members of one biological sex mate choice, choose mates of the other sex to mating, mate with (intersexual selection), and compete with members of the same sex for access to members of the opposite sex (intrasexual selection). These two forms of selection mean that some individuals have greater reproductive success than others within a population, for example because they are more Animal sexual behaviour, attractive or prefer more attractive partners to produce offspring. Successful males benefit from frequent mating and monopolizing access to one or more fertile females. Females can maximise the return on the energy they invest in reproduction by selecting and mating with the best males. The concept was first articulated by Charles Darwin who wrote of a "second agency" other than natural selection, in which competition between mate candidates could lead to speciation. The theory was given a mathematical basis by Ronald F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polygyny In Animals
Polygyny (; from Neo-Greek πολυγυνία, from πολύ- ''poly-'', "many", and γυνή ''gyne'', "woman" or "wife") is a mating system in which one male lives and mates with multiple females but each female only mates with a single male. Systems where several females mate with several males are defined either as promiscuity or polygynandry. Lek mating is frequently regarded as a form of polygyny, because one male mates with many females, but lek-based mating systems differ in that the male has no attachment to the females with whom he mates, and that mating females lack attachment to one another.Clutton-Brock T.H. (1989). ‘Review lecture: mammalian mating systems.' ''Proceedings of the Royal Society of London''. Series B, Biological Sciences 236: 339–372. Polygyny is typical of one-male, multi-female groupsBoyd, R., & Silk, J. B. (2009). How Humans Evolved (preferably the downloadable pdf version): WW Norton & Company, New York. and can be found in many species includi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Female Defense Polygyny
Female (symbol: ♀) is the sex of an organism that produces the large non-motile ova (egg cells), the type of gamete (sex cell) that fuses with the male gamete during sexual reproduction. A female has larger gametes than a male. Females and males are results of the anisogamous reproduction system, wherein gametes are of different sizes, unlike isogamy where they are the same size. The exact mechanism of female gamete evolution remains unknown. In species that have males and females, sex-determination may be based on either sex chromosomes, or environmental conditions. Most female mammals, including female humans, have two X chromosomes. Female characteristics vary between different species with some species having pronounced secondary female sex characteristics, such as the presence of pronounced mammary glands in mammals. In humans, the word ''female'' can also be used to refer to gender in the social sense of gender role or gender identity. Etymology and usage The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lek Mating
A lek is an aggregation of male animals gathered to engage in competitive displays and courtship rituals, known as lekking, to entice visiting females which are surveying prospective partners with which to mate. A lek can also indicate an available plot of space able to be utilized by displaying males to defend their own share of territory for the breeding season. A lekking species is characterised by male displays, strong female mate choice, and the conferring of indirect benefits to males and reduced costs to females. Although most prevalent among birds such as black grouse, lekking is also found in a wide range of vertebrates including some bony fish, amphibians, reptiles, and mammals, and arthropods including crustaceans and insects. A classical lek consists of male territories in visual and auditory range of each other. An exploded lek, as seen in the kakapo (the owl parrot), has more widely separated territories, but still in auditory range. Lekking is associated with an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yellow-headed Blackbird (Xanthocephalus Xanthocephalus)
The yellow-headed blackbird (''Xanthocephalus xanthocephalus'') is a medium-sized blackbird with a yellow head. It is the only member of the genus ''Xanthocephalus''. Description Measurements: * Length: 8.3-10.2 in (21-26 cm) * Weight: 1.6-3.5 oz (44-100 g) * Wingspan: 16.5-17.3 in (42-44 cm) Yellow-headed blackbirdsTwedt, Daniel J. "Ecology of yellow-headed blackbirds." ''Ecology and Management of Blackbirds (Icteridae) in North America''. CRC Press, 2017. 43-64. are considered to be relatively large blackbirds with large heads. Their name derives from the Greek word for yellow, xanthous, and the word for head, cephalus. Adults have a pointed bill. The adult male is mainly black with a yellow head and breast; they have a white wing patch sometimes only visible in flight. The adult female is mainly brown with a dull yellow throat and breast. Immature members of both sexes are brown with duller yellow plumage compared to adult males. Immature males also have some wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calopterygidae
The Calopterygidae are a family of damselflies, in the suborder Zygoptera. They are commonly known as the broad-winged damselflies, demoiselles, or jewelwings. These rather large damselflies have wingspans of 50–80 mm (compared to about 44 mm in the common bluetail damselfly, '' Ischnura elegans''), are often metallic-coloured, and can be differentiated from other damselflies by the broader connection between the wings and the body, as opposed to the abrupt narrowing seen in other damselfly families. The family contains some 150 species. The Calopterygidae are found on every continent except Antarctica. They live along rivers and streams.Córdoba-Aguilar, A. & Cordero-Rivera, A. (2005)Evolution and ecology of Calopterygidae (Zygoptera: Odonata): status of knowledge and research perspectives.''Neotrop. Entomol'' 34(6), 861-879. Etymology The name is derived from Greek ''kalos'' meaning beautiful and ''ptery'' meaning winged. Characteristics The adults have metallic bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yellow-headed Blackbird
The yellow-headed blackbird (''Xanthocephalus xanthocephalus'') is a medium-sized blackbird with a yellow head. It is the only member of the genus ''Xanthocephalus''. Description Measurements: * Length: 8.3-10.2 in (21-26 cm) * Weight: 1.6-3.5 oz (44-100 g) * Wingspan: 16.5-17.3 in (42-44 cm) Yellow-headed blackbirdsTwedt, Daniel J. "Ecology of yellow-headed blackbirds." ''Ecology and Management of Blackbirds (Icteridae) in North America''. CRC Press, 2017. 43-64. are considered to be relatively large blackbirds with large heads. Their name derives from the Greek word for yellow, xanthous, and the word for head, cephalus. Adults have a pointed bill. The adult male is mainly black with a yellow head and breast; they have a white wing patch sometimes only visible in flight. The adult female is mainly brown with a dull yellow throat and breast. Immature members of both sexes are brown with duller yellow plumage compared to adult males. Immature males also have some wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polygyny Threshold Model
The polygyny threshold model is an explanation of polygyny, the mating of one male of a species with more than one female. The model shows how females may gain a higher level of biological fitness by mating with a male who already has a mate. The female makes this choice despite other surrounding males because the choice male's genetics, territory, food supply, or other important characteristics are better than those of his competitors, even with two females on the territory. Graphical depiction The graphical depiction of the model presented in Gordon Orians' 1969 paper is often used to explain the concept. The graph shows two curves on a graph of biological fitness versus environmental quality. Environmental quality refers to the quality of the male's territory. The left curve, labeled monogamous, is the perceived biological fitness for a female entering into a monogamous relationship with a given male. The right curve, labeled bigamous, shows the fitness of the same female enter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mating Systems
A mating system is a way in which a group is structured in relation to sexual behaviour. The precise meaning depends upon the context. With respect to animals, the term describes which males and females mate under which circumstances. Recognised systems include monogamy, polygamy (which includes polygyny, polyandry, and polygynandry), and promiscuity, all of which lead to different mate choice outcomes and thus these systems affect how sexual selection works in the species which practice them. In plants, the term refers to the degree and circumstances of outcrossing. In human sociobiology, the terms have been extended to encompass the formation of relationships such as marriage. In plants The primary mating systems in plants are outcrossing (cross-fertilisation), autogamy (self-fertilisation) and apomixis (asexual reproduction without fertilization, but only when arising by modification of sexual function). Mixed mating systems, in which plants use two or even all three mating s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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