Social dynamics of group courtship behavior in male red-sided garter snakes (Thamnophis sirtalis parietalis).

Examined the social dynamics of the formation of mating balls (gatherings of males) during the mating period of red-sided garter snakes to determine whether the mating balls are formed simply because of a common attraction to the female or whether males are stimulated by the mating balls themselves. Nine test males and 9 stimulus females were used in tests, along with 55 other males, to measure the effect of other courting males. Results show that male Ss courted females more actively when other males were also courting the female than when they were alone with her, suggesting that the female is more attractive to the male when courted by other males. A positive correlation was observed between the number of additional males present and the amount of courtship activity shown by the test male toward the stimulus female. The extent to which the courtship activity of the test males was stimulated by the presence of additional courting males was not influenced by how actively the additional males courted. Results suggest that males are intrinsically stimulated by mating balls. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Roles of the vomeronasal and olfactory systems in courtship behavior of male garter snakes.

Studied whether male garter snakes required intact vomeronasal or olfactory systems to detect the pheromone that triggers the chin-pressing behavior of courtship. Male garter snakes with testosterone propionate pellets implanted sc were tested for courtship displays with estradiol-benzoate-treated females. Three groups of 10 males were formed from snakes exhibiting strong courtship responses. Bilateral olfactory nerve cuts were attempted on 1 group, vomeronasal nerve cuts on a 2nd, and control surgeries on a 3rd. All snakes in the olfactory nerve cut and control groups courted after surgery, and 3 snakes in each group copulated. More than half of the snakes in the olfactory nerve cut group had complete nerve cuts. Nine of the 10 snakes in the vomeronasal nerve cut group exhibited no courtship responses after surgery. The 1 snake in this group that courted was the only snake in which intact vomeronasal nerve fascicles were observed. Data indicate that male garter snakes without functional olfactory systems do court and mate normally, but that male garter snakes without functional vomeronasal systems exhibit no courtship responses. (38 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Temperature activation of courtship behavior in the male red-sided garter snake (Thamnophis sirtalis parietalis): Role of the anterior hypothalamus-preoptic area.

Adult male red-sided garter snakes (Thamnophis sirtalis parietalis) received radio-frequency lesions prior to 17 weeks of low-temperature hibernation. Animals found to have bilateral lesions of the anterior hypothalamus-preoptic area ({ah-poa}) failed to exhibit courtship behavior on emergence from hibernation. Those individuals in which the major portion of the destruction was centered in the anterior POA also exhibited deficits in thermoregulatory behavior. Animals that received unilateral lesions of the {ah-poa} initiated courtship behavior after controls and had an abbreviated period of courtship; these animals exhibited normal responses to thermal stimuli. Male snakes with lesions outside the {ah-poa} courted normally and demonstrated no differences in thermoregulatory behavior compared with the surgical controls. These results indicate that in male red-sided garter snakes, an intact {ah-poa} is critical for the integration of thermal stimuli that activate seasonal courtship behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Role of the anterior hypothalamus–preoptic area in the regulation of courtship behavior in the male Canadian red-sided garter snake (Thamnophis sirtalis parietalis): Lesion experiments.

Lesions of the medial preoptic area and/or the ventromedial hypothalamus resulted in an abrupt and immediate decline in courtship behavior in 28 male Canadian red-sided garter snakes. Lesions of the more anterior portions of the preoptic area resulted in a more gradual, delayed decline in courtship behavior. Ss sustaining lesions dorsal, ventral, or caudal to the anterior hypothalamus–preoptic area (AH–POA) exhibited no change in courtship behavior relative to controls. Measurements of testis size, spermatogenic stage, and circulation levels of androgens revealed no differences between any of the groups. There were marked differences in the change in hematocrit over time between the groups. Results indicate that the AH–POA is involved in the control of courtship behavior in the adult male red-sided garter snake. Moreover, it is suggested that the stimulus affecting the AH–POA to activate courtship is temperature-related. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cardiotrophin-1, a cytokine present in embryonic muscle, supports long-term survival of spinal motoneurons

Activation of courtship behavior in male red-sided garter snakes is independent of androgens. Only exposure to extended periods of low temperature with subsequent warming stimulates courtship in males. The pineal gland is thought to transduce temperature as well as photoperiodic information in reptiles. Therefore, we explored the relationship of the pineal and melatonin to sexual behavior in this species. Pinealectomy of male garter snakes disrupted sexual behavior upon emergence from a 17-week period of low temperature in approximately 60% of treated individuals in each of the 3 years of study. However, 40% of the males were unaffected by the pinealectomy, engaging in vigorous courtship. Administration of exogenous, chronic melatonin did not significantly modulate the effect of pinealectomy. Upon pinealectomy in the autumn (before hibernation), plasma levels of melatonin fell. However, upon emergence from hibernation, melatonin levels in pinealectomized (PINX) and sham-treated (SHAM) animals were equivalent, indicating extrapineal source(s) of melatonin. However, PINX males did not exhibit a diel cycle in melatonin levels upon emergence. Instead, melatonin remained elevated through the subsequent 24-hr period. SHAMs did exhibit a diel cycle. Ten days after emergence, PINX animals either had a disrupted/abnormal melatonin cycle and were non-courters or had a cycle similar to SHAM males and courted. Therefore, a normal diel cycle of melatonin appeared necessary for the proper expression of courtship behavior. These results suggest that the pineal in snakes 1) is part of a complex, multi-oscillator system as it is in birds and lizards and 2) may play a role in maintaining polymorphism in timing of reproductive behavior.     

Determinants of mating success in the golden hamster (Mesocricetus auratus): III. Female acceptance of multiple mating partners.

Four studies with golden hamsters investigated females' acceptance of multiple mating partners. Findings show that females that mated only with a single, recently mated male ran a high risk of pseudopregnancy or reduced litter size. Females paired with males that had mated to satiety 30 min, 8 hrs, or 24 hrs earlier showed a reduced willingness to engage in lordosis than did females paired with a sexually rested (2 wks) male. Females paired with recently mated males were also more likely to mate with additional (fresh) males than were females exposed to rested males. Females presented with 2 anesthetized stimulus males readily discriminated between sexually rested and recently mated individuals. Neither prior sexual experience nor recent copulatory activity was required for this discrimination. It is suggested that multiple-male mating (promiscuity) in female hamsters may be an adaptation against an infertile mating as a consequence of mating with a single, recently mated, sperm-depleted male. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Eggs of a female Japanese quail are more likely to be fertilized by a male that she prefers.

Male Japanese quail (Coturnix japonica) that conspecific females preferred in a 10-min, forced-choice test of affiliative preference were more likely than were males not preferred in such a test to fertilize females' eggs when subsequently mated with them, although preferred and nonpreferred males mated equally often with females. Further, the probability that a nonpreferred male would fertilize a female's eggs was significantly increased if she watched while he courted and mated with another female. The results indicate that in Japanese quail (a) affiliative preference reliably predicts females' choices of fathers for their offspring and (b) females may have some degree of control over whether the males with whom they mate actually fertilize their eggs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Manipulation for the treatment of occupational low back pain

Female colour polymorphism is a perplexing characteristic of many damselfly species. In Ischnura elegans three female phenotypes occur, one of which has the same blue coloration as the male (androchromes) whilst the others are inconspicuous brown gynochromes (infuscans and infuscans-obsoleta morphs). By marking a natural population near Rome, Italy, we found that all female phenotypes have similar survivorship, but they differ in mating frequency. Androchromes represented 55% of females but were involved in 43% of matings, whereas infuscans females represented 27% of females and 40% of matings and the infuscans-obsoleta phenotype 18% of females and 17% of matings. Old androchromes stored significantly less sperm in their spermatheca than old gynochromes, suggesting that they had mated less often. The majority of mature androchromes were observed alone (54%) when the majority of gynochromes (82-84%) were mating. When live tethered conspecifics were presented to males, blue models (male and androchrome female) were less attractive than brown models (gynochrome females). In contrast, all female colour morphs and males were equally (highly) attractive to males when the models were dead. Androchromes were significantly larger than gynochromes. Our results indicate that androchrome females mate less often than gynochromes, which could be a means of avoiding unnecessary and costly matings, but some androchrome females failed to reproduce (mate or oviposit) probably because they were unable to mate at all. The different explanations for the maintenance of this polymorphism in I. elegans are discussed. Copyright 1998 The Association for the Study of Animal Behaviour.     

The function of Barbary macaque copulation calls

In a wide variety of animal species, females produce vocalizations specific to mating contexts. It has been proposed that these copulation calls function to incite males to compete for access to the calling female. Two separate advantages of inciting male-male competition in this way have been put forward. The first suggests that as a result of calling, females are only mated by the highest ranking male in the vicinity (indirect mate choice hypothesis). The second proposes that copulation calling results in a female being mated by many males, thus promoting competition at the level of sperm (sperm competition hypothesis). In this paper, I give results from the first experimental study to test these hypotheses. Playback was used to examine the function of copulation calls of female Barbary macaques (Macaca sylvanus) in Gibraltar. Although rank did not affect lone males' likelihood of approaching copulation calls, when playbacks were given to pairs of males only the higher ranking individual approached. Moreover, females were mated significantly sooner after playback of their copulation call than after playback of a control stimulus. These results suggest that the copulation calls of female Barbary macaques play a key role in affecting patterns of male reproductive behaviour, not only providing an indirect mechanism of female choice, but also promoting sperm competition by reducing the interval between copulations. Potential fitness benefits of inciting male-male competition at these two levels are discussed.     

Behavior and single gene substitution in Drosophila melanogaster. I. Mating and courtship differences with w, cn, and bw loci

The effect of single allele substitutions into an isogenic background in Oregon-R inbred lines of Drosophila melanogaster on courtship and mating patterns has been studied. A comparison has been made between the white locus w, wco, we, the wild type w+, cn, bw, and cn bw to test the effect of eye pigmentation in influencing courtship and mating patterns. It was found that w, we, wco, cn, and bw females were more successful in mating than were wild-type and cn bw females, cn bw females being less successful than wild-type females. Also, w and cn bw males were equally successful in mating but less successful than wild-type males during the 20-min test period. The mutant males performed as well as the wild-type after courtship was initiated. The behavioral parameters measured were (1) courtship latency, the time from exposure of male to female until orientation; (2) mating speed, the time from beginning of orientation of male to female until successful copulation, and (3) copulation time.     

Cultural transmission of vocal traditions in cowbirds (Molothrus ater) influences courtship patterns and mate preferences.

In this study, the authors tested the cultural transmission of vocal traditions in cowbirds (Molothrus ater). Young cowbirds from a South Dakota (SD) population were housed over winter with adults of the SD population or with adults from an Indiana (IN) population. Song differences between the original SD and IN adult models were acquired by South Dakota culture (SDC) and Indiana culture (INC) males, respectively, and were transmitted to a 2nd cultural generation of birds. During playback tests of SDC and INC songs, SD females gave more copulatory responses to SDC songs. Finally, males with SD-like songs courted SDC females preferentially in breeding season tests, whereas males with IN-like songs courted INC females preferentially. These results indicate that the transmission of vocal traditions plays a fundamental role in the courtship patterns and mating decisions of cowbirds. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social olfaction in male brown lemmings (Lemmus sibiricus?=?trimucronatus) and collared lemmings (Dicrostonyx groenlandicus): II. Discrimination of mated and unmated females.

Four experiments were conducted with 32 brown and 80 collared male lemmings. When tested in a Y-maze olfactometer, both species preferred the odor of unmated receptive females to the odor of females with which they had just copulated. Similarly, sexually satiated Ss preferred the odor of an unmated receptive female to that of a strange female that had recently copulated with another male. Sexually experienced Ss without recent copulatory experience also demonstrated this preference, but sexually naive Ss did not. Sexually satiated collared lemmings preferred the odor of bedding from a novel estrous female to bedding from the female with which they had just copulated even when the bedding was collected before mating occurred. Results suggest that discrimination between prior mates and unmated females may be based on individual recognition as well as recognition of subclasses of females (i.e., mated vs unmated, familiar vs unfamiliar). (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A gender-specific mechanism for pair bonding: Oxytocin and partner preference formation in monogamous voles.

Previous studies have demonstrated that central administration of vasopressin but not oxytocin facilitates pair bonding in the monogamous male prairie vole. This study tested vasopressin and oxytocin in the formation of the female vole's preference for a particular male partner. Initial studies showed that in monogamous female prairie voles (but not in nonmonogamous congeners), mating was followed by a partner preference that endured for at least 2 weeks. Nonmating prairie vole females developed a partner preference following oxytocin infusions, but not after vasopressin or cerebrospinal fluid infusions. Females given a selective oxytocin antagonist showed normal mating behavior, yet failed to develop a partner preference. The vasopressin antagonist failed to block partner preference formation in mated females. These results suggest that oxytocin, released with mating, may be critical to formation of a partner preference in the female prairie vole; this contrasts to vasopressin, which appears to be more important for pair bonding in the male of this species. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mating behavior of the golden-orb-weaving spider, Nephila clavipes: II. Sperm capacitation, sperm competition, and fecundity.

60 female golden-orb-weaving spiders were permitted to mate at different times and were sacrificed at systematic intervals so that stored sperm could be examined microscopically for morphological changes. In order to assess female fecundity as a function of time of mating, some females from each of 10 mating groups were allowed to lay eggs. Results show that when females were mated immediately after final molt, sperm changed from an encysted to a flagellate state prior to oviposition. Following oviposition, many sperm became nonflagellate. For females mated later in adulthood, sperm became flagellate more rapidly, and the interval between final molt and oviposition was extended. Capacitation was reflected not only in morphological changes in the sperm but also in additional factors such as agglutinization and the extension of the time between final molt and oviposition in late-mated females. Findings are described as providing a link to the understanding of the sperm competition process. It is suggested that if the interval between matings with the 1st and 2nd male is long, sperm priority is likely; however, if successive matings are relatively close together, sperm priority may not occur. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Female regulation and choice in the copulatory behavior of montane voles (Microtus montanus).

To study female choice of mating partners in montane voles, a male was tethered at each end of an elongate chamber, and an estrous female was allowed to move betweeen the 2 males and a neutral area. In Exp I, using 16 females and 32 males, females with a choice of 2 gonadally intact males copulated preferentially with 1 of them. Preferred males were more effective than nonpreferred males at gaining intromission and had more thrusts per intromission. In Exp II, with 10 females, 10 castrated males, and 10 sham-operated males, females spent more time with and mated preferentially with intact rather than castrated males. It is therefore suggested that the opportunity to copulate is reinforcing for female voles and that they display distinct preferences, correlated with copulatory stimulation, for some partners. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Male traits, mating tactics and reproductive success in the buff-breasted sandpiper, Tryngites subruficollis

Buff-breasted sandpipers use a variety of mating tactics to acquire mates, including remaining at a single lek for most of the breeding season, attending multiple leks during the season, displaying solitarily or displaying both on leks and solitarily. We found that differences in body size, body condition, fluctuating asymmetry scores, wing coloration, territory location and behaviour (attraction, solicitation and agonistic) did not explain the observed variation in mating tactics used by males. Which males abandoned versus returned to leks was also not related to morphology or behaviour, and there was no tendency for males to join leks that were larger or smaller than the lek they abandoned. These results suggest that male desertion of leks was not dependent on a male's characteristics nor on the size of the lek he was presently attending. Males did join leks with larger males than their previous lek, perhaps to mate with females attracted to these larger 'hotshot' males. Males at both leks and solitary sites successfully mated. Lek tenure did not affect mating success, although lekking males appeared to mate more frequently than solitary males. Courtship disruption and to a lesser extent, female mimicry, were effective at preventing females from mating at leks, and may offer a partial explanation for female mating off leks. Our analysis that combined all males together within a year (regardless of mating tactic) indicated that males that attended leks for longer periods of time and that had fewer wing spots were significantly more likely to mate. Given some evidence that wing spotting declines with age, and that females inspect male underwings during courtship, the latter result suggests that female choice may play some role in determining male success. We suggest that male buff-breasted sandpipers may use alternative mating tactics more readily than males in other 'classic' lek-breeding species because: (1) unpredictable breeding conditions in this species' high arctic breeding range leads to low lek stability, which in turn hinders mate selection mechanisms mediated by male dominance and female choice; and (2) males are not constrained by morphological markings that indicate status or sex. Both characteristics may reduce the reproductive benefits associated with males adopting one mating tactic and result in a sort of scramble competition in which males switch between tactics as local conditions change.Copyright 1998 The Association for the Study of Animal Behaviour     

Timing of mating, sperm dynamics, and ovulation in a wild population of agile Antechinus (Marsupialia: dasyuridae)

Timing of mating, sperm transport and storage, and ovulation were examined in a wild population of agile Antechinus (Marsupialia: Dasyuridae) in order to ascertain the validity of direct comparisons between captive and field-based mating studies in this species. Mating commenced in early August, and all females had ovulated by the 27th of the month. Fifty-five percent of the mated females caught that had not yet ovulated were captured on 19-20 August. This corresponded with a peak (67%) in the ovulation date determined for pregnant females. Approximately 25.9 x 10(3) spermatozoa per side were recovered from the reproductive tract of each mated female captured (range: 1.7 x 10(3)-75.5 x 10(3) spermatozoa per side). Spermatozoa were consistently found in greater numbers in the lower isthmus (19.7 x 10(3) +/- 19.9 x 10(3) spermatozoa per side) of the oviduct ( approximately 67% of all sperm found in the female tract; range 17-94%) than elsewhere in the reproductive tract. Few spermatozoa were found in the upper isthmus, and none were detected in the ampulla. Sperm number in the female reproductive tract supports the hypothesis that females will mate several times within the one estrus. At the conclusion of the rut, approximately 80.0 x 10(3) spermatozoa remained in each testis and approximately 630 x 10(3) spermatozoa in each epididymis. Most epididymal spermatozoa were restricted to the distal corpus/proximal cauda regions of the duct. This study shows that both field and laboratory reproductive data correlate well in the agile Antechinus and that successful breeding is indeed an exercise in reproductive brinkmanship.     

Differences in behavioral responses to a competitive mating situation in two species of dwarf hamster (Phodopus campbelli and P. sungorus).

Social groups consisting of a female and two adult males, of two closely related species, Phodopus campbelli and P. sungorus, were observed during a 2-hr mating test. The behavioral analysis revealed (a) significant differences between the two species in the ability of the dominant male to exclude the subordinate male from mating with the estrous female and (b) significant changes in the pattern of copulation by the dominant male in response to the presence of a second male even when the second male was not mating with the female. Dominant male P. sungorus were always successful in preventing subordinate males from mating. In contrast, subordinate male P. campbelli mated with the female in 6 of 12 groups in spite of high levels of aggression and the potential for serious injury. When both P. campbelli males mated, dominant males ejaculated first and most frequently. The response to the presence of a second male in P. sungorus included an accelerated copulatory pattern, with decreased durations of individual ejaculatory series and postejaculatory refractory periods. This resulted in an average of one extra ejaculation during the first hour of testing. The temporal pattern of mating in P. campbelli was not accelerated by the presence of a second male, but the intromission/mount ratio was increased significantly, and the duration of the ejaculatory lock decreased. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mate choice and mate competition influence male body size in Japanese medaka

A sexual size dimorphism usually occurs when size-dependent reproductive advantages exist in only one sex. Studies on Japanese medaka, Oryzias latipes, have demonstrated reproductive size advantages in females but not in males, even though males and females are similar in body size. We conducted mate-choice and mate-copying tests in which a female could first associate with, then mate with, either a large (>/=1 sd+X standard length) or a small male (相似文献   

Regulation of female sexual behavior in the golden hamster: behavioral effects of mating and ovarian hormones

In the female hamster, sexual receptivity was abbreviated following copulation. Short-term effects of mating, lasting approximately 24-48 hr, were observed in females mated in either estradiol- or estradiol-and-progesterone-induced estrus. Long-term effects of copulation, of 9 days or more in duration, were apparent only in females chronically treated with both estradiol and progesterone, suggesting that progesterone exposure prolongs the inhibitory effects of mating. When progesterone stimulation was intermittent through the use of short-acting injection procedures, recovery from mating could be detected in 48 hr and was complete within 96 hr after copulation. The pattern of behavioral response to ovarian hormones in unmated females was also documented, replicating the "biphasic" effect of progesterone in this species. The inhibitory effects of mating and progesterone summate to produce consistent decrements in female sexual receptivity. It is postulated that short-term postcopulatory abbreviations in receptivity would reduce the vulnerability of the estrous female while long-term inhibitions, interacting with sustained progesterone stimulation, would reduce the probability of mating during pregnancy when hormone levels are elevated for a prolonged period.