PubMed HealthSearch

SEARCH · PubMed Health

Results for “Sexual Behavior, Animal”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

Monogamy in mammals.

This review considers the behavioral, ecological, and reproductive characteristics of mammals exhibiting monogamy, i.e., mating exclusivity. From a discussion of the life histories of selected species of monogamous primates, carnivores, rodents and ungulates, several trends emerge. Two forms of monogamy occur, Type I, facultative, and Type II, obligate. The selective pressures leading to these two forms of monogamy may have been different. Facultative monogamy may result when a species exists at very low densities, with males and females being so spaced that only a single member of the opposite sex is available for mating. Obligate monogamy appears to occur when a solitary female cannot rear a litter without aid from conspecifics, but the carrying capacity of the habitat is insufficient to allow more than one female to breed simultaneously within the same home range. Within both types of monogamy, the following traits are typically seen: (1) adults show little sexual dimorphism either physically or behaviorally: (2) the adult male and female exhibit infrequent socio-sexual interactions except during the early stages of pair bond formation. Additional trends specific to mammals exhibiting obligate monogamy are: (1) the young exhibit delayed sexual maturation in the presence of the parents, and thus only the adult pair breeds; (2) the older juveniles aid in rearing young siblings; and (3) the adult male (father) aids in the rearing of young by any or all of the following: carrying, feeding, defending, and socializing offspring.

Animals

Age and sexual behavior of Japanese macaques (Macaca fuscata).

The sexual behavior of the Arashiyama West troop, a natural semi-free-ranging troop of Japanese macaques, was studied during the 1973-1974 and 1974-1975 breeding seasons. The troop was transported intact from Japan to its current location in South Texas. There they have been free to move about in a 42.2-hectare electric fence enclosure. This report describes the relationships among age, aging, and sexual behavior. Males beginning at the age of 2.5 years were observed to series-mount estrous females in the double foot clasp mount position. Mounting in series in the double foot position is the normal pattern for Japanese macaque males. The ejaculation of semen with concomitant body movements indicative of orgasm begins at age 4.5 years at the earliest and continues until death. Males 4.5 and 5.5 years of age, sexually mature in the physiological sense, were not consistently sexually mature in the behavioral sense. The oldest male displayed traits that appear analogous to traits observed in aging human males. Females begin to experience estrus at 3.5 years of age. However, like pubescent males, pubescent females display behavioral patterns of sexual immaturity. The oldest female of the troop has remained sexually active. The attainment of sexual maturity by adulthood can be viewed as a learned process leading to efficiency and prowess, followed in old age by sexual involution.

Aging

Neonatal treatment of hamsters with barbiturate alters adult sexual behavior.

Male and female hamsters were given 50 micrograms pentobarbital, 100 micrograms pentobarbital, or 100 micrograms d-amphetamine on postnatal Days 2-4. When tested for masculine sexual behavior in adulthood, males treated with 100 micrograms pentobarbital showed behavioral deficits when tested with testes intact as well as after castration and treatment with testosterone propionate. Deficits shown by 50 micrograms pentobarbital males were overcome by testosterone replacement. When tested for feminine sexual behavior, males treated with 50 micrograms pentobarbital showed enhanced lordotic responses whereas males treated with 100 micrograms d-amphetamine showed no differences from controls when tested for female sexual behavior or when tested for male sexual behavior. Drug treatments had no effect on adult masculine or feminine sexual behavior in neonatally treated females. The results of this study show that pentobarbital can inhibit normal masculinization of the male when given during behavioral sexual differentiation.

Animals

Variation in age at puberty in monkeys.

5 female and 3 male patas monkeys and 6 female and 3 male talapoin monkeys matured in a captive breeding colony. Age at puberty is given, and some variation discussed. The talapoin, a very small monkey, becomes adult at 4 1/2 years for females, 1 or 2 years later for males. The patas, a rather large monkey, becomes adult at 2 1/2 years, for females, and 1 or 2 years later for males. Both these ages for puberty differ from data for the rhesus monkey which has been accepted as generalizable to all Old World monkeys. Possible causes of differences between species in average age at puberty are discussed, including nutrition, environmental inconstancy, and relative size of infant and mother. It is suggested that age at first conception, a biologically more relevant index than menarche, should be considered as a potentially important adaptive variable when describing primate species.

Age Factors

The delayed anovulation syndrome: influence of hormones and correlation with behaviour.

Experiments were conducted to assess the influence of the ovary and various steroid treatments on the development of the delayed anovulatory syndrome (DAS) in female rats. The influence of neonatally administered androgen on the development of ovarian function and female sexual behaviour was studied. It was found that neither the presence of the ovary nor the administration of oestrogen or androgen affected the time-course of the DAS. Doses of androgen which produced the DAS had little effect on female sexual behaviour and there was no evidence of time-dependent changes in sexual behaviour comparable to the time-dependent changes of ovarian physiology observed during the DAS.

Animals

Effects of exogenous gonadotropic and steroid hormones on the social behaviour and gonadal maturation of male domestic ducklings Anas platyrhynchos L.

Male domestic ducklings were injected during their first month of life with mammalian gonadotrophins (ovine LH or FSH, HMG) or gonadal steroids (testosterone or oestradiol). LH and testosterone stimulated sexual behaviour while oestradiol inhibited the increase of aggression observed in control birds during the experiment. The mammalian gonadotrophins did not increase plasma testosterone but nevertheless they all stimulated the testis growth. Several hypotheses which could explain this finding (stimulation of spermatogenesis without any apparent effect on testosterone) are discussed and the possibility of a direct action of LH on the sexual behaviour is analysed. Social displays were only moderately stimulated by testosterone and not at all by gonadotrophins. The hormonal controls of these behaviour patterns remains thus largely unknown.

Aggression

[Observations on the acceleration of the sexual maturation of female mice by the presence of males and by exogenous oestrogen (author's transl)].

The influence of the presence of adult males on the acceleration of sexual maturation of female mice was examined under various experimental conditions and compared with the influence of exogenous oestrogen. The criteria of sexual maturation were not equally influenced. It is concluded that sexual maturation is a complex feature and that acceleration of single criteria does not signify sexual maturation.

Animals

Courtship latency in male Drosophila melanogaster.

Male Drosophila melanogaster differ in the age at which they reach sexual maturity following eclosion from the pupa. Courtship latency, which is the time taken by a male to initiate courtship of a conspecific female, is related to age. Young males take significantly longer than older males to begin courtship. The probability that a male will initiate courship is influenced by the physiological state of the female. Males of different genotypes readily court mature (3-day-old) virgin females, but they differ significantly in their reaction to immature (12-hr-old) and fertilized females. Genes located on the third chromosome largely control male courtship latency, but responses to immature and fertilized females have different genetic bases, suggesting that the relevant stimulus inputs governing these responses also differ. The adaptive significance of courtship directed toward immature or fertilized females, which rarely mate, probably depends on the average level of sexual responsiveness of potentially receptive mature virgin females in a given population.

Age Factors

Sex, migraine and serotonin interrelationships.

Sexual deficiency or frank impotence in man could be due to an imbalance of monoamines, particularly 5-HT, at the mating center level. An absolute or relative excess of 5-HT seems to antagonize testosterone at the level of the mating center receptors in the brain. Plasma testosterone levels in so-called psychological impotence are normal. When the 5-HT concentration in sexually deficient men is sufficiently decreased with parachlorophenylalanine (PCPA) treatment and testosterone levels increased following its administration, a vivid sexual stimulation appears in about half of the untractable cases. Similar results are observed by substituting testosterone with monoamine oxydase inhibitor (MAOI) in PCPA-treated volunteers. Furthermore, MAOI-PCPA are administered to emphasize the brain shift between serotonin and catecholamines. Yet the PCPA-MAOI treatment avoids the prostate carcinogenic risk of testosterone administration in aging males, and seems to have euphorizing effects stronger than those expected only from MAOI therapy. Because of the several side effects of PCPA-MAOI testosterone, the present experiments should be interpreted very cautiously.

5-Hydroxytryptophan