Sexual behavior and factors affecting female reproduction in house and field crickets

The objective of this investigation was to clarify the adaptive significance of female sexual behaviours in the house cricket, Acheta domesticus, and the Texas field cricket, Gryllus integer. Experiments were focussed primarily on: nutritional factors affecting female reproductive success; the ontogeny of female sexual behaviours; female mating frequency and progeny production; and the pattern of sperm competition. Reproduction of singly mated female A. domesticus assigned to 3 nutritional regimes was compared . Females fed a vitamin and protein-enriched mouse chow, cannibalistic females, and starved females produced on the average, 513 , 200 and 68 offspring, respectively. Cannibals probably could not obtain the same amounts of essential nutrients as females fed mouse chow. Reabsorption of oocytes was likely the major factor contributing to the decreased reproduction of starved females. In addition, female !. domesticus fed mouse chow, but allowed constant access to males produced 11 times as many offspring than did females fed corn meal. Females fed corn meal probably could not absorb or synthesize enough dietary lipids, thus resulting in poor ovariole growth. Female !. domesticus first mate at an average adult age of 7 days, closely corresponding to when they first exhibit positive phonotaxis. Females mate repeatedly and often consume the externally attached spermatophore. In ~. domesticus, females allowed constant access to males produced significantly more offspring than did single maters. Similarly, doubly mated G. integer females produced more offspring than did single maters. This difference resulted largely from the failure of many single maters to reproduce. Remating by female crickets partly functions in offsetting the possibility of a failed initial mating. Nymph production increased significantly with the time the spermatophore was attached in singly mated ~. domesticus. Spermatophore consumption by the female was not affected by male guarding behaviour, and the interval between mating and eating of the spermatophore may often be shorter than the time required for maximum insemination. Some degree of sperm depletion in singly mated !. domesticus and G. integer may have occurred. The patterns of daily offspring production of singly and multiplymated females suggests that a factor provided by a male during mating stimulates female oviposition and/or egg production. Female crickets also might acquire nutrition from spermatophore consumption, a benefit that is augmented by female multiple mating. The electrophoretic examination of various allozymes in ~. integer did not permit determination of a pattern of sperm competition. However, the possibility of last male sperm predominance is related to male guarding behaviour.

Sexual behavior in a one-male unit of Rhinopithecus bieti in captivity

Data regarding the sexual behavior of black-and-white snub-nosed monkeys (Rhinopithecus bieti) were collected in 1998 in a one-male unit in captivity by all-occurrences sampling during the mating season. Before the present study, little was known about the sexual behavior of this species. This study showed that female solicitation is mainly expressed as "prostration plus glancing laterally" (PG) or "sitting plus head moving up and down" (HM), and male solicitation is exhibited by the "grunt bared-teeth display." The mount-to-ejaculation ratio was 5.2 on average, and single-mount ejaculations (SMEs) were observed in only 4.4% of mounts on days with at least one ejaculation. Therefore, the main copulatory pattern of this species is multiple-mount ejaculation (MME). Females initiated 72% of 18 ejaculatory mounts. Females initiated more ejaculatory mounts than non-ejaculatory ones. In general, the patterns of sexual behavior in this species are similar to those reported for other Colobines. (C) 2004 Wiley-Liss, Inc.

Effects of female postmating odour on male sexual behaviour, in Heliconius butterflies /

The effects of the female postmating odour on male sexual behaviour were examined in Heliconius erato and H. charithonia (Lepidoptera: Nymphalidae). Predictions from the antiaphrodisiac hypothesis were tested using the two reproductive strategies of these species. Within the pupal mating strategy, results from behavioural experiments quantified and statistically tested dispersal rates of pupal-perched males to the presence of stimuli with and without the postmating odour. Results do not support an antiaphrodisiac function to the postmating odour. Similarly, within the adult courtship strategy, behavioural test results indicate that males do not alter their expenditure of energy in terms of either the duration or frequency of courtship behaviours elicited by females with and without the postmating odour. The data from both experiments did not support the antiaphrodisiac hypothesis for the function of the female postmating odour. A novel hypothesis predicting that the postmating female odour acts as an oviposition-deterring pheromone is presented.

Parental care in the common tern (Sterna Nirundo): sexual roles in a monogamous seabird

The parental behaviour of male and female Common Terns (Sterna hirundo) was documented throughout two breeding seasons at a colony near Port Colborne , Ontario. Thirteen and fourteen pairs of terns were chosen for intensive study in 1982 and 1983, respectively. The delivery of fish by males to their mates ("courtship feeding") occurred prior-to, during, and following the egg-laying period. Following the laying of the second egg, courtship feeding rates declined significantly. There was a significant, positive correlation bebween courtship feeding rates and subsequent chick feeding rates by males. The incubation rates of females were significantly higher than those of males, especially during the first ten days of incubation. Territorial attendance rates during the incubation stage were similar for males and females. During the chick stage, territorial attendance rates of females were significantly higher than those of males. The size of fish fed to chicks by males increased as the chicks grew older and chick feeding rates of males were approximately three times higher than female rates. Based on these quantitative differences in parental care activities, the cumulative parental time investment by the two sexes was very similar. However, the energetic investment by males was likely greater than that by females, since male parental contributions (e.g. courtship feeding and chick feeding) often entailed extensive foraging behaviour.

Sexual behavior in Spanish adolescents of divorced parents

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Effects of prenatal hydrocortisone acetate exposure on fertility and sexual behavior in male rats

The aim of the present study was to investigate the effects of hydrocortisone during the prenatal period and its later repercussions on the fertility and sexual behavior of male rats. Pregnant rats were treated (s.c.) with hydrocortisone acetate, at 1.5 mg/day on the 17th, 18th, and 19th days of gestation. Decreased body weight and no alteration in anogenital distance were observed in male offspring. Adulthood, presented reductions of body weight, plasma testosterone levels, and seminal-vesicle wet weight without secretion as well as no alteration in the wet weights of the testes, epididymis, and seminal vesicle with secretion in the treated group. Males exposed to hydrocortisone during the prenatal period were able to mate with normal females, which became pregnant but exhibited an increased number of post-implantation losses. In spite of this, these treated males exhibited decreased male sexual behavior and the appearance of female sexual behavior after these male rats were castrated and pretreated with exogenous estrogen. These results indicate that exposure to hydrocortisone in the later stages of pregnancy may have a long-term effect on the fertility and sexual behavior of mate rats, suggesting an incomplete masculinization and defeminization of the central nervous system. (C) 2003 Elsevier B.V. (USA). All rights reserved.

Effects of neonatal clomiphene citrate on fertility and sexual behavior in male rats

In order to investigate the participation of estrogen during the period of brain sexual differentiation, male rats were treated with clomiphene citrate in the neonatal phase. Fertility and sexual behavior were assessed during adult life. Sexual maturation, body weight, and wet weight of the testes were unchanged. Although the adult male rats treated with clomiphene in the neonatal phase presented a significant reduction in the frequency of mounts, 90% of these rats were able to mate with normal females, which became pregnant. However, these females exhibited a significantly increased number of pre- and post-implantation losses. When these adult male rats were castrated and received estrogen, 60% presented female sexual behavior (receptive behavior and acceptance of mount). Thus, treatment of pups with clomiphene immediately after birth has a long-term effect on the reproductive physiology and sexual behavior of male rats. (C) 2002 Elsevier B.V. All rights reserved.

Post-partum testosterone administration partially reverses the effects of perinatal cadmium exposure on sexual behavior in rats

This study investigated the effects of perinatal cadmium exposure on sexual behavior, organ weight, and testosterone levels in adult rats. We examined whether immediate postpartum testosterone administration is able to reverse the toxic effects of the metal. Forty pregnant Wistar rats were divided into three groups: 1) control, 2) 10 mg kg-1 cadmium chloride per day, and 3) 20 mg kg-1 cadmium chloride per day. These dams were treated on gestational days 18 and 21 and from lactation 1 to 7. Immediately after birth, half of the offspring from the experimental and control groups received 50 μl (i.p.) of 0.2% testosterone. Male sexual behavior, histological analysis and weight of organs as well as serum testosterone levels were assessed. Results showed that both cadmium doses disrupted sexual behavior in male rats, and postnatal treatment with testosterone reversed the toxic effects of 10 mg kg-1 cadmium and attenuated the effects of 20 mg kg-1 cadmium. Body weight and absolute testis, epididymis, and seminal vesicle weight were decreased by the higher cadmium dose, and testosterone supplementation did not reverse these effects. Serum testosterone levels were unaffected by both cadmium doses. No histological changes were detected in all organs analyzed. Maternal cadmium exposure effects in sexual parameters of male rat offspring were explained by the altered masculinization of the hypothalamus. We suggest that cadmium damaged cerebral sexual differentiation by its actions as an endocrine disruptor and supported by the changes discretely observed from early life during sexual development to adult life, reflected by sexual behavior. Testosterone supplementation after birth reversed some crucial parameters directly related to sexual behavior.

An examination of the Gonorrhea Cases & Places Study: An analysis of the Theory of Gender and Power, Situational/Environmental Variables Theory, and Sexual Script Theory as it relates to risky sexual behavior in African American adults

Objective. The purpose of the study is to provide a holistic depiction of behavioral & environmental factors contributing to risky sexual behaviors among predominantly high school educated, low-income African Americans residing in urban areas of Houston, TX utilizing the Theory of Gender and Power, Situational/Environmental Variables Theory, and Sexual Script Theory. Methods. A cross-sectional study was conducted via questionnaires among 215 Houston area residents, 149 were women and 66 were male. Measures used to assess behaviors of the population included a history of homelessness, use of crack/cocaine among several other illicit drugs, the type of sexual partner, age of participant, age of most recent sex partner, whether or not participants sought health care in the last 12 months, knowledge of partner's other sexual activities, symptoms of depression, and places where partner's were met. In an effort to determine risk of sexual encounters, a risk index employing the variables used to assess condom use was created categorizing sexual encounters as unsafe or safe. Results. Variables meeting the significance level of p<.15 for the bivariate analysis of each theory were entered into a binary logistic regression analysis. The block for each theory was significant, suggesting that the grouping assignments of each variable by theory were significantly associated with unsafe sexual behaviors. Within the regression analysis, variables such as sex for drugs/money, low income, and crack use demonstrated an effect size of ≥ ± 1, indicating that these variables had a significant effect on unsafe sexual behavioral practices. Conclusions. Variables assessing behavior and environment demonstrated a significant effect when categorized by relation to designated theories.

An examination of the Gonorrhea Cases & Places study: An analysis of the Theory of Gender and Power, Situational/Environmental Variables Theory, and Sexual Script Theory as it relates to risky sexual behavior in African American adults

Objective. The purpose of the study is to provide a holistic depiction of behavioral & environmental factors contributing to risky sexual behaviors among predominantly high school educated, low-income African Americans residing in urban areas of Houston, TX utilizing the Theory of Gender and Power, Situational/Environmental Variables Theory, and Sexual Script Theory. ^ Methods. A cross-sectional study was conducted via questionnaires among 215 Houston area residents, 149 were women and 66 were male. Measures used to assess behaviors of the population included a history of homelessness, use of crack/cocaine among several other illicit drugs, the type of sexual partner, age of participant, age of most recent sex partner, whether or not participants sought health care in the last 12 months, knowledge of partner's other sexual activities, symptoms of depression, and places where partner's were met. In an effort to determine risk of sexual encounters, a risk index employing the variables used to assess condom use was created categorizing sexual encounters as unsafe or safe. ^ Results. Variables meeting the significance level of p<.15 for the bivariate analysis of each theory were entered into a binary logistic regression analysis. The block for each theory was significant, suggesting that the grouping assignments of each variable by theory were significantly associated with unsafe sexual behaviors. Within the regression analysis, variables such as sex for drugs/money, low income, and crack use demonstrated an effect size of ≥±1, indicating that these variables had a significant effect on unsafe sexual behavioral practices. ^ Conclusions. Variables assessing behavior and environment demonstrated a significant effect when categorized by relation to designated theories. ^

Sexual behavior in penguins

Mode of access: Internet.

Sexual behavior, neuroendocrine, and neurochemical aspects in male rats exposed prenatally to stress

The present study was designed to examine some short- and long-term effects of maternal restraint stress-during the period of sexual brain differentiation-on reproductive and endocrine systems, sexual behavior, and brain neurotransmitters in male rat descendants. Pregnant rats were exposed to restraint stress for 1 h/day from gestational days (GDs) 18 to 22. Prenatal stress did not influence the wet weight of sexual organs and the quantity of germ cells in adult male pups; however, these animals showed reduced testosterone levels, delayed latency to the first mount and first intromission, and also decreased number of ejaculations. Additionally, there was an increase in the dopamine and serotonin levels in the striatum. Our results indicate that prenatal stress had a long-term effect on neurotransmitter levels and sexual behavior. In this sense, reproductive problems caused by injuries during the fetal period can compromise the later success of mating as well as the capacity to generate descendants. (C) 2004 Elsevier B.V. All rights reserved.

Doramectin reduces sexual behavior and penile erection in male rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ethics in sexual behavior assessment and support for people with intellectual disability

Sexuality is an issue of equality, rights, and ethics, especially when it comes to the sexuality of people with intellectual and developmental disabilities. This paper offers a discussion of ethics related to the assessment and intervention supports of sexual behavior in people with intellectual and developmental disabilities. A brief history of sexuality and disability is presented. Issues of sexual abuse of people with intellectual and developmental disabilities and the laws related to sterilization, pornography, sexual rights, and consent are explored. Finally, specific ethical concerns related to intervention by behavior analysts in the realm of sexual behavior are examined.

Sexual selections in the northern fall field cricket, Gryllus pennsylvanicus: a manipulation of the adult sex ratio

The operational sex ratio has long been considered an important constraint on the structure of mating systems. The effects of an experimentally manipulated sex ratio on mating behavior and selection were investigated in a polygynous species, Gryllus pennsylvanicus, where the potential exists for spatial/temporal fluctuations in sex ratio of field populations. Four different sex ratios (males: females, 5:0, 5:2, 5:5, 5:10) were investigated. Observations were conducted in late summer over two field seasons, from 2400 h , to 1000 h EST. Several male characters thought to be associated with male reproduc.tive success were studied: calling duration, searching distance, weight, fighting behavior, courtship frequency, and mating success. Variance in male mating success was used as the indicator for the opportunity for sexual selection. Total selection was estimated as the univariate regression coefficient between relative fitness and the character of interest, while direct selection was estimated as standardized partial regression coefficients generated from a multiple regression of relative fitness on each character. The opportunity for sexual selection was highest at 5:2 and lowest at 5:10. The frequency of fighting behavior was highest at 5:2 and 5:5. Fighting ability (% wins) was determined to be an important correlate of male body weight. Direct selection for increased male body weight was detected at 5:2, while total selection for body weight was seen at 5:5. Selection on male body weight was not detected at 5: 10. Calling duration decreased as sex ratio became more female-biased. Total and direct selection were detected for increased calling at 5:2, only total selection for calling was seen at 5:5, whereas direct selection against calling was detected at 5: 10. Searching distance also decreased as sex ratio became more female-biased, however no form of selection was detected for searching at any of the sex ratios. Data are discussed in terms of sexual selection on male reproductive tactics, the mating system and maintenance of genetic variation in male reproductive behavior.