Given time and training, he was able to readjust and accept his role as silverback in the troop. Ivan was rarely observed breeding with the female gorillas in his troop, and he did not sire offspring.
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Adult males exist in two different forms: the brightly colored and "fatted" dominant males, and the paler and "nonfatted" subordinate males. Both males engage in mating, but only the dominant males can sire offspring. Males sometimes fight for breeding rights which results in dominance. Though conflicts are rare, they can be deadly.
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Mating can last up to 15 minutes, during which time the pair continuously submerge and surface.Kelly, pp. 86–88. While dominant males usually monopolise reproductive females, multiple paternity is known to exist in American alligators, where as many as three different males may sire offspring in a single clutch. Within a month of mating, the female crocodilian begins to make a nest.
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The pygmy slow loris can conceive by 18 months and give birth to its first offspring by two years of age. Studbook records show that the youngest male to sire offspring was around 18 months of age, and the youngest female conceived at 16 months. Gestation length is 184–200 days, and the lactation period lasts 123–146 days. Offspring are weaned at about 24 weeks of age.
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Most primate mothers cease ovulation while breastfeeding an infant; once the infant is weaned the mother can reproduce again. This often leads to weaning conflict with infants who attempt to continue breastfeeding. Infanticide is common in polygynous species such as gray langurs and gorillas. Adult males may kill dependent offspring that are not theirs so the female will return to estrus and thus they can sire offspring of their own.
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These females also tend to gain direct benefits through the increased production of fledglings and offspring that become adults. In addition, male song repertoire length is positively correlated to annual harem size and overall lifetime production of offspring that survive. Song repertoire size alone is able to predict male lifetime number of surviving offspring. Females tend to be attracted to males with longer song repertoires since they tend to sire offspring with improved viability.
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It was observed in F. truncorum that when two males had their ability to sire offspring compared, one of the two would consistently create more progeny. In spite of this, there was no evidence to support the idea that one male would be particularly better at creating more offspring than the other. This indicates that the female is able to store different amounts of sperm from separate males, which would then result in one male producing significantly more offspring.
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Juvenile in a Costa Rican Pacific dry forest The mantled howler uses a polygamous mating system in which one male mates with multiple females. Usually, the alpha male monopolises the breeding opportunities, but if the alpha male is distracted, a lower-ranking male can get an opportunity to mate. And in some groups, lower-ranking males do get regular mating opportunities and do sire offspring. Alpha males generally maintain their status for about 2½ to 3 years, during which time they may father 18 or so infants.
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Mature Polypay rams will weigh between 240 and 300 lbs. All animals entered in a show or sale should be a twin or better and all ewes shown in a Yearling Ewe Class must have already lambed. Although Polypays are a general purpose breed, they are also known as a maternal breed because of their prolificacy, ability to breed aseasonally, early fertility, high milk production, and good mothering. In cross-breeding programs with a meat-type terminal sire offspring exhibit hybrid vigor for traits such as growth rate and carcass quality.
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For example, the lizards Eulamprus heatwolei show a behavioral syndrome with two behavioral types. There is a correlated relationship between how territorial an individual is, how likely they are to explore their environment, and what strategy they use to avoid predation. This behavioral syndrome has also been shown to influence the mating system of this species; territorial males are more likely to sire offspring with territorial females, and larger territorial males compete less with other males for mates. However, less territorial, or "floater", males and females produce consistently larger offspring than territorial parents or hybrids.
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Similar to promiscuous mating, female primates are proceptive during the first and second trimester of pregnancy in order to increase paternity confusion of their offspring. Finally, in multi-male multi-female groups, female synchrony, in which females are all fertile at the same time, can prohibit the dominant male from monopolizing all of the females. This also allows sneak copulations in which non-dominant males sire offspring. Female synchrony also serves to reduce risk of female infanticide by forcing potentially infanticidal females to focus on provisioning their own infants rather than acting aggressively.
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In addition to winemaking, grapes have been grown for the production of raisins. The earliest act of cultivation appears to have been the favoring of hermaphroditic members of the Vitis vinifera species over the barren male vines and the female vines, which were dependent on a nearby male for pollination. With the ability to pollinate itself, over time the hermaphroditic vines were able to sire offspring that were consistently hermaphroditic. At the end of the 5th century BC, the Greek historian Thucydides wrote: The period that Thucydides was most likely referencing was the time between 3000 BC and 2000 BC, when viticulture emerged in force in Asia Minor, Greece, and the Cyclades Islands of the Aegean Sea.
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During the breeding season, male testes increase significantly in size, facilitating sperm competition due to female promiscuity. Studies with the gray mouse lemur have shown that the optimal insemination period, during which a male is most likely to sire offspring, occurs early during a female's receptivity. Only during the mating season does male mortality rise above that of female mortality. Although the gray mouse lemur displays multi-male, multi-female mating patterns, studies have shown that females do exhibit indirect mate selection (a form of selected polyandry). During the study, females would mate with 1–7 males up to 11 times during their single night of receptivity, but would avoid or counteract males that attempted to monopolize mating.
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He sired a gray colt named Karazi, who won three races in France before being shipped to Del Mar for the 2007 season. Among Arazi's offspring are Congaree, who won the 2001 Wood Memorial Stakes, the 2002 and 2003 Cigar Mile Handicap, and the 2003 Hollywood Gold Cup and Carter Handicap. His reputation may be as a broodmare sire; offspring from his daughters include the ill-fated Electrocutionist, winner of the Dubai World Cup; Lahudood, winner of the 2007 Breeders' Cup Filly & Mare Turf and Eclipse Award champion turf filly; Bribon, winner of the Grade I Metropolitan Handicap in 2009; and Americain, winner of the Melbourne Cup in 2010. In September 2017 Arazi, aged 28, was reported to be enjoying his retirement at Stockwell Stud, Victoria, alongside Brief Truce, who beat him in the 1992 St James's Palace Stakes.
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In his discussion of "the desire for sexual variety", Symons reviews literature on the "Coolidge effect", the "phenomenon of male rearousal by a new female". Discussing rape, Symons suggests that because males can "potentially sire offspring at almost no cost ... selection favors male attempts to copulate with fertile females whenever this potential can be realized." He criticizes the feminist Susan Brownmiller's argument in Against Our Will (1975) that rape is not sexually motivated, writing that she inadequately documents her thesis and that all of the reasons that she and other authors have given for concluding that rapists are not motivated by sexual desire are open to criticism. Symons writes that Brownmiller's claim that the function of rape is to keep all women in a state of fear has been "vigorously contested", and that it is also an example of a naïve form of functionalism, which is unacceptable since no process that might generate such "functions" has been shown to exist.
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