Failure of familiar males to prevent alien male-induced implantation block (the Bruce effect) in laboratory mice

Implantation failure in newly inseminated females induced by exposure to alien males (the Bruce effect) was significantly reduced when the females were housed with the stud male. By contrast, newly inseminated females housed with a familiar male during exposure to alien males exhibited a high rate of implantation failure. The results suggest that the protective effect of the stud male on implantation is not because of the familiarity of the female with his odour cues. The results are consistent with the view that the newly inseminated female mouse identifies her coital partner as an individual because she becomes 'imprinted' with his odour during the pericopulatory period.     

Behavioural responses of female Neogobius melanostomus to odours of conspecifics

The behavioural responses of reproductive and non‐reproductive female round gobies Neogobius melanostomus to water conditioned by reproductive and non‐reproductive males and females were tested. The behavioural responses of reproductive female round gobies exposed to odour of reproductive males included increased time spent near the source of the odour, elevated swimming velocities and directed movement to and around the odour source when compared with their responses to control water. These results suggested that pheromones released from reproductive males may induce spawning behaviour in reproductive females. Non‐reproductive females exposed to reproductive female odour spent significantly more time near the odour source of reproductive females compared with control water. Non‐reproductive females also showed directed movement towards and around the odour source when exposed to reproductive female odour. These results suggested that round gobies use inter‐sexual and intra‐sexual pheromones and that both sex and reproductive status are important in the detection and release of these pheromones.     

Seasonal control of odour preferences of meadow voles (Microtus pennsylvanicus) by photoperiod and ovarian hormones

During the spring-summer breeding season, female meadow voles prefer odours of males over those of females, but in the autumn-winter season of reproductive quiescence this preference is reversed. Females housed in long (14 h light/day) and short (10 h light/day) photoperiods, respectively, had odour preferences comparable to those of spring and autumn voles, respectively. The preference of long-photoperiod voles for male over female odours was reversed by ovariectomy and restored by treatment with oestradiol. By contrast, neither ovariectomy nor oestradiol affected odour preferences of short-photoperiod voles. Long days appear to influence olfactory preferences by altering ovarian hormone secretion. The failure of oestradiol to affect odour preferences in short photoperiods suggests that the neural substrates mediating this behavioural response are refractory to oestrogens during the nonbreeding season.     

幼小鼠对种内几种化学信息的识别和反应

50年代以来,国际上相继开展了一些关于化学信息在小家鼠繁殖中作用的研究,并在实验室中揭示了一些反应:如集群雌鼠气味使雌鼠性周期延长的Lee-Boot效应,雌鼠气味能解除集群雌鼠对性周期的抑制、并促使它们同期发情的Whitten效应,以及陌生雄鼠气味中断妊娠的Bruce效应等等。但是,在成鼠间起作用的几种化学信息,是否能被幼鼠感受,对幼鼠的发育和性成熟是否产生影响,还是一个未知的问题。 影响小鼠发育的因素很多,除环境因子外,近来还出现了有关社群因素中外激素对小鼠性成熟影响的报道,发现雄鼠或给予雄激素的雌鼠有促进幼雌鼠性成熟的作用,范志勤发现父本气味和陌生雄鼠气味对幼雌鼠性成熟均有促进作用。但是,目前关于种内雌鼠气味、集群雌鼠气味、幼鼠气味影响性成熟的研究尚不多见。有关各种气味对性成熟效应的比较的报道亦少。本文的目的在于通过实验方法,阐明种内的几种化学信息,诸如父本、陌生雄性、雌性、集群雌性、幼雌等几种气味,对幼雌小鼠性成熟的影响,并据此了解幼鼠识别这几种信息的能力。     

Female reproductive responses to photoperiod and male odours in the subterranean rodentCtenomys talarum

The tuco-tucoCtenomys talarum Thomas, 1898 is a solitary subterranean rodent that breeds seasonally in coastal sand-dune grasslands from Argentina. We assessed whether short-day photoperiod determines the onset of reproduction by an increase in female’s receptivity and whether male odour interacts with photoperiod as a cue by producing a greater response in receptivity. Receptivity was measured by an increase in the percentage of vaginal epithelial cells, particularly cornified cells. Females were trapped during their non-reproductive season (summer-long days) and randomly assigned to different day-length experimental groups: constant summer (CS), early winter (EW), and natural (NA) photoperiod. We examined the vaginal epithelium using vaginal smears during the first experimental phase (120 days) to test the effect of photoperiod. In the second experimental phase (15 days), we presented the females with male-soiled shavings to test the effect of photoperiod and male odor.Ctenomys talarum females showed some evidence of reproductive responsiveness to photoperiodic cuing. The proportion of epithelial cells peaked earlier in females when winter day-length was advanced than in females under natural photoperiod. Contrary to that expected, male odours did not stimulate female receptivity. These results suggest that, while photoperiod may participate in regulating reproduction, the integration of other environmental and social factors, as well as the identification of bodily conditions that lead to differences in individual response needs further consideration.     

Cross-modality effects during male-male interactions of jumping spiders

An important prediction from game theory is that the value of a resource influences the level to which male-male conflict escalates. Earlier experimental studies have shown that the seven salticid species we study here (Bavia aericeps, Euryattus sp., Hypoblemum albovittatum, Jacksonoides queenslandicus, Marpissa marina, Portia africana and Simaetha paetula) determine by sight whether a female is a conspecific or a heterospecific and then escalate the intensity with which they interact (i.e., they adopt behaviour that is likely to put them at greater risk of injury after detecting the presence of a conspecific female). Here the earlier studies are extended by using the odour of conspecific females (experimental tests) and heterospecific females (control tests), and by presenting each male with his mirror image as well as having two males interact with each other. Findings from this study suggest that, for J. queenslandicus and P. africana, the odour of conspecific females, more than the odour of heterospecific females, primes the male to escalate conflict with a potential rival. However, this was not found for the other five species tested.     

Brief exposure to the odour of a parasitized male alters the subsequent mate odour responses of female mice

Parasites can affect mate choice, with females preferentially selecting parasite-free males. Prior exposure to, or experience with, males has also been suggested to influence mate responses. Here, we examined the effects of an immediate, brief (1 or 15 min) pre-exposure to the urinary and associated odours of either an uninfected male house mouse,Mus domesticus , or a male infected with the natural murine nematode parasite, Heligomosomoides polygyrus, on the subsequent responses of female mice to the odours of infected and uninfected males. Using an odour preference test we found that females displayed a marked overall preference for the odours of uninfected males. Pre-exposure to the odours of a parasitized male decreased female preference for nonparasitized males and increased female preference for parasitized males. This ‘prior male’ effect was evident for both the total odour preference and initial odour choice. Females pre-exposed to the odour of a parasitized male displayed decreased choosiness and made no particular initial choice of a male, while still maintaining an overall preference for the odours of uninfected males. These shifts in initial choice and odour preference were not directly associated with either female stress responses or stress-related odour cues of the males. Our findings show that female mice can distinguish between parasitized and nonparasitized males on the basis of odour and suggest that a brief exposure to the odours of infected males influences females' immediate odour preferences, and their subsequent preference for and choice of males. This rapid, infection-associated ‘prior male’ effect may contribute to the reported variations in female mate preference and choice. Copyright 2003 Published by Elsevier Science Ltd on behalf of The Association for the Study of Animal Behaviour      

The dynamics of the bacterial associations in the vaginal mucus of female Syrian hamsters during the sexual cycle]

Autofluctuations in the numbers of bacteria, leukocytes and epithelial cells were observed in the vaginal secretion of Syrian female hamsters. The amplitude of fluctuations depended both on individual features of females and on environmental factors like light conditions. It was suggested that vaginal bacteria perform functions of a stimulator for local immunity to protect against infections and play a sanitary role to eliminate epithelial cells and remains of spermatozoids. A case is possible that products of the bacterium vital activity contribute also to the formation of female sex pheromone.     

Male hamsters discriminate estrous state from vaginal secretions and individuals from flank marks

It is clear that male hamsters discriminate between the odors of individual, conspecific females, as shown by using habituation-dishabituation methods. However, it is not clear from past research whether male hamsters are able to discriminate between the odors of estrous and non-estrous females. A series of habituation-dishabituation experiments was conducted to determine whether males discriminated between different estrous cycle states using two female secretions, those from flank-glands and vaginal secretions. We found that, when habituated to a female flank-gland secretion, males discriminated between this female and a second female on the test trial, whether both were in estrus, both were in diestrus, or one was in estrus and the other in diestrus. There was no difference, however, in the magnitude of their dishabituation response toward flank-gland odors of females in estrus and diestrus. These results suggest that males use flank-gland odors to gain information primarily about individuals. When tested with vaginal secretions in habituation-dishabituation tests, males only showed differences in investigation when the second female was in estrus, indicating that males use vaginal secretions to gain information primarily about reproductive state.     

Visual and olfactory cue interaction in resource-location by the blowfly, Lucilia sericata

Abstract. The interactions between olfactory and visual cues in the landing responses of the blowfly Lucilia sericata (Meigen) (Diptera: Calliphoridae) were examined in a laboratory wind tunnel. The odour of liver and sodium sulphide solution released at 1 L/min, resulted in a greater number of landings, closer to, but downwind of, the central odour release point, than when odour was absent. Three-day-old protein-deprived females landed in greater numbers than protein-fed female flies of the same age; no difference existed between 6-day-old protein-fed or protein-deprived females. Six-day-old, protein-fed flies landed closer to the odour source than did 3-day-old, protein-fed flies. In the presence of odour, flies landed closer to the central release point when it was accompanied by a visual cue. No such effect of the visual cue was evident in the absence of odour. When a plain white sticky-surface (25 × 25 cm) was paired with an identical white surface plus odour, approximately equal numbers of flies landed when the surfaces were placed together; increasingly higher numbers of flies landed on the surface with the odour cue when the distance between the surfaces was increased. When a white surface with a visual cue was presented with the plain white surface plus odour, more flies landed on the white surface with the visual cue than on the plain white surface with odour when they were close together. However, as these two surfaces were moved apart, flies landed increasingly more on the surface with the odour than the surface with the visual cue. The results show that while odour cues may enhance the induction of landing by female L. sericata , visual cues are important when selecting a final landing site.     

雌性布氏田鼠对雄鼠气味的辨别

通过雌性布氏田导其配偶和陌生雄鼠气味的辨别实验,以及无交配经历的成年雌鼠对社会等级不同的陌生雄鼠气的辨别实验发现,有生育经历的雌鼠对陌生雄鼠气味的探究行为明显多于对配偶气味的控究,但雌鼠在配偶雄鼠气味周围的停留时间、自身修饰行为和何处行为的发生频次和持续地陌生雄鼠,没有交配经历的雌鼠对处于从鼠地位的雄性个体气味探究行为多于对优势雄性的控究,而其他行为表现没有明显差异。表明,雌性布氏田鼠可以利用气味     

Seasonal, sexual and developmental differences in hoopoe Upupa epops preen gland morphology and secretions: evidence for a role of bacteria

The uropygial glands of birds serve multiple functions, and there is great interspecific variability in the composition and properties of their secretions. A special case is the secretion in the hoopoes Upupa epops, and green woodhoopoes Phoeniculus purpureus, which, contrary to the commonly white and odourless secretions, are dark with pungent odour. Recently, bacteria have been isolated from glands of both woodhoopoes and hoopoes and here we test the hypothesis that bacteria are responsible of some of the special properties of glands and secretions of this group of birds. We explore natural seasonal changes and intersexual differences in the properties of hoopoe glands and secretions, check the natural occurrence of bacteria within secretions, and analyse the effect of experimental injection of antibiotics on uropygial gland properties. Male glands underwent no seasonal changes, and their secretions were invariably white and odourless, very similar to female glands outside the breeding season. However, in comparison to the uropygial gland of non‐breeding females, those of incubating females showed a marked increase in size and volume of secretion produced, which became dark and pungent. All these parameters increased until the hatching date and returned to values similar to those in the prelaying phase towards the end of the nestling period. Nestling glands produced secretions similar to those of females in colour and odour. Gland size of both females and nestlings predicted the amount of secretion produced. Microscopic techniques confirmed the presence of bacteria at high density and in active division in all dark secretions examined. The antibiotic treatment significantly reduced the load of enterococci in nestling glands, did not affect size of glands, but diminished the volume of secretion, which was lighter in colour than that of control nestlings. In nesting females, the experimental injection of antibiotic affected some measurements of gland size and secretion colour. Because the experiment did not affect general health estimates (immunocompetence, body condition or growing) of nestlings, our results suggest that some of the special properties of hoopoe glands are mediated by the presence of symbiotic bacteria.     

绵羊对化学信息的识别及其在繁殖行为中的作用

在动物生殖的各个阶段,都包含有嗅觉的作用。家畜经历了长期驯养过程之后,某些化学通讯行为有时会逐渐消失,但是它们仍然保持着野生祖先释放和感知气味的能力。 本项实验的目的在于测定绵羊产生和感知气味的能力及其在生殖中的作用。 取新疆细毛羊和哈萨克羊尿液和阴道分泌物作为外激素源,实验测定公、母羊对异性外激索的反应,记录嗅闻时间和行为表现。 结果表明,细毛公羊仅仅通过嗅觉,就有选择发情母畜的能力。它们对发情母羊化学倩息的趋近频次和嗅闻时间均高于对未发情者的频次和时间。 未曾交配过的一龄畜也能区分发情和未发情母畜的气味,但识别能力不如成畜。一定的性经验及随后的学习过程影响这种能力的发展。 实验表明,公羊在发情母畜阴遭分泌物处停留时间较长,嗅闻频次却并不高于对未发情畜阴道分泌物的次数。试畜对尿液的反应较阴道分泌物强。可见两处都含有表明性及性状况的化学信息存在。公畜对母畜化学信息表现蜷唇、舐、嗅、拱刺激源等行为。阴道分泌物所引起的行为类型则较尿液贫乏。 母羊亦表现出选择公畜化学信息的特性,它们在公羊气味处舐、排尿等。一龄畜反应亦弱于成畜。 新疆细毛羊和哈萨克公羊两个品种都表现了选择异品种信息的倾向。 绵羊是在近距离感受化学信息的,这就在一定程     

The attraction of virgin female hide beetles (Dermestes maculatus) to cadavers by a combination of decomposition odour and male sex pheromones

ABSTRACT: INTRODUCTION: The hide beetle Dermestes maculatus (Coleoptera: Dermestidae) feeds as an adult and larva on decomposing animal remains and can also be found on human corpses. Therefore, forensic entomological questions with regard to when and how the first receptive females appear on carcasses are important, as the developmental stages of their larvae can be used to calculate the post-mortem interval. To date, we know that freshly emerged males respond to the cadaver odour of post-bloated carcasses (approximately 9 days after death at Tmean = 27degrees), being attracted by benzyl butyrate. This component occurs at its highest concentration at this stage of decay. The aim of our study was to determine the principle of attraction of virgin females to the feeding and breeding substrate. For this purpose, we tested the response of these females to headspace samples of piglet cadavers and male sex pheromones [(Z9)-unsaturated fatty acid isopropyl esters] in a Y-olfactometer. Because we expected that such an odour combination is of importance for virgin female attraction, we tested the following two questions: 1) Are virgin female hide beetles attracted by a combination of cadaver odour and male sex pheromones? 2) During which decomposition stage do the first virgin females respond to cadaver odour when combined with male sex pheromones? RESULTS: We found that young virgin females were attracted to the cadaver by a combination of cadaver odour and male sex pheromones. Neither cadaver odour alone nor male sex pheromones alone was significantly more attractive than a solvent control. Our results also gave a weak indication that the first young virgin females respond as early as the post-bloating stage to its associated decomposition odour when combined with male sex pheromones. CONCLUSIONS: Our results indicate that freshly emerged males possibly respond to cadaver odour and visit carcasses before virgin females. Being attracted to cadavers when male sex pheromone is perceived as well, virgin females can optimise their reproductive possibilities.     

Ratings of different olfactory judgements in schizophrenia

We assessed the influence of schizophrenia on different olfactory tasks. Forty patients with schizophrenia (20 males and 20 females) and 40 control subjects (20 males and 20 females) were tested. The experiment included two sessions. Initially, 12 odorants were presented at a rate of one per minute. The subjects were asked to rate intensity, pleasantness, familiarity and edibility for each odour using linear rating scales. The odorants were then presented a second time and the subjects were asked to identify them. The results showed that the scores for pleasantness, familiarity, edibility and identification but not intensity were disturbed in patients when compared with control subjects. Furthermore, the familiarity judgement of male patients was more often deficient than that of female patients and they rated odorants as being inedible when the women judged them as neutral. Considered together, these data show that our olfactory test may be used in patients with schizophrenia for evidencing various dysfunctions specific to different types of olfactory processing that represent steps in the odour name identification process.     

Pheromonal Recognition of Females Takes Precedence over the Chromatic Cue in Male Iberian Wall Lizards Podarcis hispanica

Sex recognition is based on colour signals in many species of lizards. However, olfactory stimuli are also clearly involved, and many species might rely more on chemoreception. We aimed to examine whether colour pattern or odours, or both, are used in sex recognition and which cues elicit courtship of females by males of the lizard Podarcis hispanica . We experimentally manipulated the coloration and odour of female P. hispanica , thereby creating groups with all combinations between coloration and odour of males and females. Using data from staged encounters, we compared the responses of resident males to manipulated and unmanipulated individuals (males and females). Responding males reacted significantly more aggressively to female intruders with male odours, independently of their coloration. Nevertheless, coloration seemed to be important in long-distance sex recognition since, in the first minutes, females painted as females received a lower number of aggressive responses. Both colour and odour were important in eliciting male courtship. However, females painted as females and with female odours were preferentially courted. Comparisons with unmanipulated male and female intruders agreed with these expectations. Therefore, at close range, odoriferous cues seem to be more important than colour patterns in sex recognition, but female coloration is also useful at long range to deter the aggressive response of males and to elicit courtship in conjunction with odours.     

Olfactory communication and the importance of different odour sources in the ferret (Mustela putorius f. furo)

Olfactory communication has a major role in solitary carnivores, particularly during the breeding season. Scent-marking behaviour in ferret (Mustela putorius f. furo) has been well studied, but not the significance of the deposited odours for the animal. We compared the interest in urogenital, anal and body odours of opposite-sex conspecifics between male and female ferrets and investigated both sexes’ discrimination ability (familiar vs. unfamiliar) for these three opposite-sex odours and the use of its ability by females during the breeding season. Males are more interested than females in the urogenital odour of the opposite sex. Male body odour probably did not interest females and males are somewhat interested in the female one. However, anal odour of the opposite sex is as interesting for males as for females and both sexes are able to discriminate familiar anal odour from an unfamiliar one. Moreover, females could use this ability when they must choose to have some sensory contact between olfactory familiar and unfamiliar males since they prefer to be in contact with the former. These results are coherent with behavioural differences observed between male and female solitary mustelids in the field and in captivity, and the consortship success of resident males compared to roaming males.     

Female sexual behavior in hypogonadal mice with GnRH-containing brain grafts

Hypogonadal female mice respond to GnRH-containing fetal preoptic area (POA) implants in the third ventricle with vaginal opening and persistent vaginal estrus, ovarian, and uterine development and increased gonadotropin secretion. When these females are mated with normal males, reflex ovulation results in pregnancy. In the present study, POA implants derived from neonatal pups, whether male or female, were also capable of supporting reproductive development in the hypogonadal female mice. Evaluation of female sexual behavior in the mice with grafts showed that these mice responded to normal males with comparable levels of lordosis as are seen in normal female mice on the proestrous days of their cycles.     

Cycles of mating behaviour, oestrogen and progesterone in the thick-tailed bushbaby (Galago crassicaudatus crassicaudatus) under laboratory conditions

Vaginal smears and blood samples were taken throughout the reproductive cycle of female Galago c. crassicaudatus. Blood plasma was assayed for oestradiol and progesterone, and vaginal smears were initially classified dioestrus or vaginal oestrus. During vaginal oestrus the females were tested daily for sexual receptivity by being placed with a male. Those days on which the male achieved intromission were reclassified as behavioural oestrus. During dioestrus the females were tested weekly with males. Female receptivity increased and then declined across a 6-day period of behavioural oestrus during the 44-day cycle. Fully cornified smears were characteristic of the period of maximal receptivity and oestradiol secretion. The luteal phase lasted 24 days with a plasma progesterone peak midway through dioestrus.     

Affinity towards maternal odour and offspring dispersal in the common lizard

Kin competition is known to strongly influence the spacing behaviour of juveniles in the common lizard, a species which is only weakly social and has no parental care. We examined whether variation in offspring dispersal propensity was associated with variation in their ability to discriminate odours of their mothers versus unknown females. We caught pregnant females in two populations and reared them in the laboratory until parturition. Just after birth, we recorded the juvenile response to the odour of either their mother or an unrelated female. Mothers and offspring were then released at the mother's last capture point, and juvenile movement was monitored by recapture for 2 years. Philopatric individuals were more attracted to the odour of their mother and more repulsed by the odour of an unrelated female than dispersers. In this species, ability to discriminate maternal cues appears to be implied in the spacing behaviour of juveniles. Since juvenile males and females reacted in the same way, the main role of mother discrimination is likely to be the avoidance of kin competition by promoting juvenile dispersal. This does not necessary require mother discrimination to imply mother recognition, or not to be implied in other functions such as inbreeding avoidance. Further research is needed to clarify these points. We suggest that context-dependent kin discrimination may be involved in the spacing behaviour of a large number of species, even for those species where other social functions for kin discrimination have been proposed.