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In 1935, 101 cane toads, B. marinus, were introduced into north Queensland, Australia in an attempt to control the greyback cane beetle, Dermolepida albohirtum, a pest of sugar cane fields. The cane toad was, however, completely unable to control the beetles and itself became a successful pest. Since their arrival, cane toads have been implicated in the population declines of many native frog species and mammalian and reptilian predators. These effects are through predation, competition and the toxic secretions produced by the toad, poisoning potential predators. While the toxic nature of their secretions has been long known, only a part of the chemical complexity of the secretion has been identified to a molecular level. Our study aims to look at how diverse the chemical composition of cane toad skin secretions is, as well as its variability across life-history stages, between individuals and also whether different populations of toads may show differences in their chemistry. Beyond this, the chemical ecology of the toad, which probably includes pheromonal communication, may offer opportunities for control of this pest. [ABSTRACT FROM AUTHOR]

Preliminary investigations have been conducted to identify the chemical composition of carpal gland secretions from feral pigs in the lowland tropical rainforest of NE Australia. Carpal glands are located along the inner part of the front legs and their secretion may be distributed to the surrounding vegetation and bedding sites. Secretions were collected from the external surface of the glands by swabbing with filter paper discs. Compounds were then extracted in distilled ether and analysed by capillary gas chromatography. Secretions from boars and reproductive females contained more compounds than those from non-reproductive females. Only seventeen compounds were found in the secretions collected from boars and reproductive females, while one compound was only present in secretions from reproductive females. In boars compounds were at higher concentrations than in reproductive females. Lowest concentrations were found in non-reproductive females. Boars and reproductive females have more compounds with a higher molecular weight than non-reproductive females. The similarity in the chemical composition of carpal gland secretions from boars and reproductive females may be responsible for the same response that these animals trigger in conspecifics, i.e. avoidance behaviour. Further investigations will focus on the potential these secretions may have as repellents in feral pig control. [ABSTRACT FROM AUTHOR]

Olfactory stimuli are frequently integrated into zoo enrichment programs. This ‘olfactory enrichment' can stimulate reproduction or naturalistic behaviour, enhance enclosure exploration, or reduce inactivity. However, not all scents achieve their desired goals, and can in fact bring about undesirable behaviour such as increased levels of stereotypy. Few attempts have been made to quantify the impact of introducing olfactory stimuli to zoo enclosures, and there are inherent difficulties when designing, implementing and evaluating olfactory enrichment. Firstly, it is difficult without appropriate chemical analyses to anticipate what information a scent conveys, and therefore whether it will be received as an excitatory or aversive stimulant. Second, more practical difficulties are encountered. Consideration needs to be given to (i) the choice of scent used, its relevance and motivation, (ii) how to present the scent in time and space, (iii) individual variation in response rates and neophobia (fear of novelty) to scents, and finally (iv) the health implications linked to the use of olfactory stimuli. This paper reviews the olfactory stimuli used in zoos as enrichments and their reported effects. Practical suggestions are made to encourage and stimulate more empirical quantification of olfactory stimulation in zoo animals. [ABSTRACT FROM AUTHOR]

Small mammals are subject to predation from mammalian, avian and reptilian predators. There is an obvious advantage for prey species to detect the presence of predators in their environment, enabling them to make decisions about movement and foraging behavior based on perceived risk of predation. One technique commonly exploited to assess this risk is to use the odours of the faeces and/or urine of their predators to determine presence/absence and the length of time since a predator passed through an area. I examined the effect of faecal odours from marsupial and eutherian predators, and a native reptilian predator, on the behavior of three endemic Australian rodent species (the Fawn-footed Melomys Melomys cervinipes, the Bush Rat Rattus fuscipes and the Giant White-tailed Rat Uromys caudimaculatus) in rainforest remnants on the Atherton Tableland, North Queensland, Australia. Infrared camera traps were used to assess visit rates of rodents to odour stations containing faecal and control odours. Rodents avoided odour stations containing predator faeces, but did not avoid herbivore or control odours. The responses of the three prey species differed: in the late wet season U. caudimaculatus avoided predator odours, while R. fuscipes and M. cervinipes did not. In contrast, in the late dry season all three species avoided odour stations containing predator odours. I speculate that these differential responses may result from variations in life history traits between the species. [ABSTRACT FROM AUTHOR]

In hamsters and inbred mice, pheromone-containing chemosensory signals originating from the animal's own species (conspecific) and other species (heterospecific) produce differential patterns of immediate early gene (IEG = Fos/FRAs) expression in the medial amygdala. In males of both species, conspecific stimuli, regardless of gender or putative function, activated neurons in both anterior and posterior medial amygdala (MeA, MeP). With heterospecific stimuli, MeA was activated but MeP appeared to be suppressed. MeP neurons expressing GABA-receptor were selectively suppressed by heterospecific stimuli at the same time as the GABAergic caudal intercalated nucleus (ICNc) of the amygdala was activated, suggesting suppression of MeP by ICN. We propose that information on conspecific chemosignals with preprogrammed meaning (pheromones) is analyzed by MeP neurons, probably influenced by gonadal steroid status. Information about heterospecific stimuli that activate anterior medial amygdala via the vomeronasal organ appears to have restricted access to MeP. Signals from conspecific males that are potentially threatening elicit different patterns of activation in MeP than other conspecific signals. In hamsters, male flank gland secretion activates predominantly GABA-immunoreactive neurons and mainly in ventral MeP (MePv). Male mouse urine also activates predominantly MePv in mice. This region responds to predator odors in rats and is reported to do so in mice. These findings, with other data, support a division of labor in medial amygdala according to the reproductive or defense-related potential of the stimuli. There is some evidence for a convergence of information on conspecific and heterospecific threatening stimuli but, so far, the details are not entirely consistent. In our experiments with hamsters and mice, stimuli from potential predators (cat urine, cat collar) like other heterospecific stimuli, activated MeA and not MeP. Others studying mice found activation in ventral MeA (MeAv) during male-male interactions and in MePv by cat collar stimuli. Since the submission of this paper we have also found activation in mouse MePv by stronger cat collar stimuli (see note at end of text). [ABSTRACT FROM AUTHOR]

Squamata reptiles are often divided in two major groups based on the main sensory modality that they use: the chemical/visual and the visual taxa. Although Liolaemus lizards belong to the visual taxon Iguania, I show that they may depend heavily on chemosignals in many different aspects of their life. The combined information from Liolaemus and other "visual genera" that use chemosignals, urges us to reconsider the classical dichotomous segregation of Squamata in terms of sensory modality. In addition, further work is also necessary to understand the role of chemical signals in "visual" lizards. [ABSTRACT FROM AUTHOR]

Tongue-flicking is a sensory-gathering behavior used by snakes to deliver odorants to the vomeronasal organ. In the present study we provide a detailed description of environmental control and motor patterns of tongue-flicking in garter snakes, Thamnophis sirtalis. Tongue-flicks were monitored during prey extract trailing, foraging, delivery of air-borne odors and in an open field. Tongue-flick rates increased during airborne odor delivery and as a function of prey extract concentration during trailing, as previously reported. Motivation and prey consumption appeared to modify tongue-flick patterns since 1. tongue-flick rates were higher under foraging conditions than in an open field where no prior prey consumption had occurred and no prey odors were present; and 2. tongue-flick rates were elevated after prey consumption. The number of oscillations and the duration of tongue extensions were significantly reduced following tongue-substrate touches, suggesting that tongue contact with the substrate is the immediate stimulus for tongue retraction. [ABSTRACT FROM AUTHOR]

Fourteen premature infants (born at 30-33 weeks gestational age) were tested for their responses to the odours of different categories of human breast milk that are commonly available in intensive care nurseries: viz. their own mother's fresh and frozen milk, and frozen / pasteurized donor milk. Freezing reduced, but did not eliminate the stimulating effect of breast milk odour. The pattern of results obtained at 36 weeks post-conceptual age suggests that preterm infants may recognize the odour of their own mother's milk, and/or pasteurisation reduces the salience of milk odour. Breast milk odour elicits heightened sucking activity, which could have a positive effect on the development of breastfeeding behaviour. [ABSTRACT FROM AUTHOR]

Milk and the nipples of mammalian females have long been known to release attraction in conspecific newborns. This applies also to humans, in whom breast odour cues control infant state and directional responses. Such cues from the whole breast as well as from the isolated areola delay crying onset and stimulate positive orientation and oral actions in infants. Native secretions from areolar glands are especially salient to newborns in which they intensify oral-facial actions and respiration. Thus, odorous compounds from areolar glands may be in a position to play a role, among many other determinants, in establishing the processes pertaining to milk production, transfer and intake by infants. [ABSTRACT FROM AUTHOR]

Among mammals, rabbits (Oryctolagus cuniculus) show unusually limited maternal care and only nurse for a few minutes once each day. Successful suckling depends on pheromonal cues on the mother's ventrum, which release a stereotyped and distinctive pattern of nipple-search behaviour in the young, and which have been termed the nipple-search pheromone. The present report summarizes what is currently known about this unusually effective chemical signal and compares this with information in more recent reports of a rabbit mammary pheromone thought to achieve the same function. We draw attention to anomalies in the present state of knowledge regarding the nature and action of these two sets of chemical signals, and thus to the continuing uncertainty as to the chemical nature and source of the cues governing nipple-search behaviour, and thus successful suckling, in the newborn rabbit. [ABSTRACT FROM AUTHOR]

Lactating female rabbits (Oryctolagus cuniculus) nurse once daily for 5 min. The pups are thus forced to localize the nipples quickly. The females emit multiple chemosignals to guide them, among which are common odors derived from dietary aromas and one identified pheromone. Thus, the mammary pheromone (MP) released in rabbit milk is highly behaviorally active: it is a potent releaser of suckling-related behaviors in pups. The MP also acts as a strong reinforcer for early odor learning. Both of these functions of the MP are active right after birth and are thus in a position to play a central role in neonatal adaptation. However, the releasing function and the reinforcing functions of the MP follow different time-courses, suggesting that they are controlled by different underlying mechanisms. These data illustrate how a same chemical signal can carry distinct functions in a newborn mammal. [ABSTRACT FROM AUTHOR]

Females of many species choose to mate with relatively unrelated males in order to ensure outbred, heterozygous offspring. There is some evidence to suggest that the MHC is involved in mate choice decisions, either because MHC heterozygous offspring are more resistant to disease, or because the highly detectable odours associated with this region allow it to act as a marker of general inbreeding. To determine which role the MHC plays it is necessary to disentangle this region from the genetic background, a requirement which has generally proven difficult to achieve. We argue that the emphasis on MHC's role in mate choice has resulted in other potential markers of inbreeding being neglected, and discuss the evidence for MHC disassortative mating, the interaction with genetic background, and a possible role for alternative markers of inbreeding. [ABSTRACT FROM AUTHOR]

Many terrestrial mammals, including voles, self-groom when they encounter odors of opposite-sex conspecifics. Voles also spend different amounts of time self-grooming when they are exposed to odors of reproductively active and reproductively quiescent opposite-sex conspecifics, suggesting that self-grooming may be involved in the behaviors that support reproduction. If self-grooming is affected by the reproductive condition of the donor and the groomer, it is also likely that their ages will influence the amount of time that the groomer will self-groom. The objective of this paper was to test the hypothesis that age of the groomer and the scent donor affects the amount of time that meadow voles, Microtus pennsylvanicus, spend self-grooming when exposed to bedding scented by opposite-sex conspecifics. Older males (12-13 mo-old) spent more time self-grooming than younger males did (2-3 mo-old and 8-9 mo-old) when they were exposed to odors of 2-3 mo-old and 8-9 mo-old female voles. Younger males spent similar amounts of time self-grooming in response to odors of 2-3 mo-old, 8-9 mo-old, and 12-13 mo-old female voles. Female voles, independent of their age, spent more time self-grooming in response to odors of 12-13 mo-old males relative to 2-3 mo-old and 8-9 mo-old males. These data demonstrate that voles discriminate between the odors of different age opposite-sex conspecifics and adjust the amount of time they self-groom when exposed to them. The data augment the view that self-grooming is a specialized form of olfactory communication between the sexes. [ABSTRACT FROM AUTHOR]

The ability to recognize familiar conspecifics appears to be widespread among vertebrates and influences a variety of behavioural interactions including mate selection. Female choice of males has been shown to vary according to male familiarity, but interestingly in some species this favours familiar males, while in others unfamiliar males are preferred. Preference for unfamiliar partners might result from the attempt to minimise inbreeding costs by avoiding mating with individuals encountered during development, or with those sharing relatedness cues. Conspecifics that are familiar through prior mating experience might be avoided in species that benefit from a promiscuous mating system, again resulting in preference for unfamiliar mates. Conversely, familiar mates may be favoured in monogamous species where formation of a pair bond is important for parental investment, and when familiarity provides an opportunity for females to assess the quality and compatibility of potential mates. Thus different types of familiarity may have differing effects on mate choice, with the direction of preference being determined by other aspects of life history, such as the likelihood of inbreeding, the importance of polyandry, and the role of social dominance and territoriality in reproductive success. [ABSTRACT FROM AUTHOR]

Even in rodents, there is no clear evidence of the existence of sexual pheromones mediating instinctive intersexual attraction. In this review we discuss previous results of our group indicating that female mice reared in the absence of male-derived chemosignals are ‘attracted' by some components of male-soiled bedding, presumably detected by the vomeronasal organ. In contrast, male odors (olfactory stimuli) only acquire attractiveness by means of their association with the innately ‘attractive' vomeronasal-detected pheromones. These ‘attractive' male pheromones are rewarding to adult females, since they induce conditioned preference for a place where they are repeatedly presented to the females. Pheromone reward seems independent of the dopaminergic neurotransmission in the tegmento-striatal pathway, and uses mechanisms and circuits apparently different to those of other natural reinforcers. [ABSTRACT FROM AUTHOR]

Mate recognition is an essential component of successful reproductive behavior, and in rodent species, is primarily guided by the perception of social odors in the environment. Importantly, there is substantial evidence that species or sexual odor preferences may be regulated by early olfactory experience, although considerable variability in the plasticity of these behaviors has been observed. The current chapter summarizes what is known regarding the role of early olfactory experience in the development of adult odor preferences, synthesizing data across species, sex, and behavioral paradigms. [ABSTRACT FROM AUTHOR]

In this chapter, we review recent data about the involvement of both the main and the accessory olfactory system in mate recognition and the control of sexual behavior in mice. Whereas the main olfactory system seems to play a central role in mate recognition in both male and female mice, clear sex differences emerge with regard to which olfactory system plays a more important role in the control of sexual behavior. Indeed, the main but not the accessory olfactory system seems to be more important in regulating sexual behavior in male mice, whereas in female mice, the accessory olfactory system seems to play a critical role in the control of mating. Olfaction is of primary importance for social recognition in mammals, including mice. Thus mice use odors to distinguish sex, social or reproductive status of conspecifics (Brennan and Zufall 2006; Brown 1979). In addition, odors have been shown to facilitate the display of sexual behavior (e.g. Thompson and Edwards 1972) and to induce neuroendocrine responses (e.g. pregnancy block in female mice; Brennan and Keverne 1997). [ABSTRACT FROM AUTHOR]

Vaginal marking is a reproductively-oriented scent marking response, in which female Syrian hamsters deposit vaginal secretions in response to odor cues from male conspecifics. Converging lines of evidence suggest that vaginal marking functions as a solicitational signal, or an advertisement of a female's impending sexual receptivity. Although vaginal marking is commonly used as an assay of proceptivity, the neural control of vaginal marking remains largely unknown. In this chapter, we will review the existing literature on vaginal marking, synthesizing evidence from behavioral, endocrine, and neuroanatomical studies that indicate targets for the neural control of vaginal marking. Lastly, we will describe preliminary data from our laboratory that suggests a possible neural circuit for the descending control of vaginal marking in female Syrian hamsters. [ABSTRACT FROM AUTHOR]

She-males are male garter snakes that elicit courtship behavior from other males during the breeding season. Initially thought to consist of a small sub-set of males which retained their attractive nature throughout the breeding season, recent behavioral data suggests that most, if not all, males undergo a period of ‘she-maleness' upon first emerging from winter hibernation before losing their attractive nature shortly after emergence. Utilizing behavioral experiments and chemical analyses, we sought to discern whether newly-emerged male red-sided garter snakes (Thamnophis sirtalis parietalis) display a pheromone profile similar to the female sexual attractiveness pheromone. Sequestered in the skin lipids of females and responsible for triggering male courtship behavior, this pheromone has been previously linked with long-term she-maleness in this species. Results from courtship trials demonstrated that newly-emerged males are attractive to other males, although not to the same degree as females. Subsequent chemical analyses of skin lipids from females and newly-emerged males showed no quantitative or qualitative difference in the components constituting the sexual attractiveness pheromone. Thus, it appears that the majority of males in this species emerge with a female-like pheromone profile and subsequent physiological changes, yet to be identified, are responsible for the short- vs. long-term nature of this phenomenon. [ABSTRACT FROM AUTHOR]

Plethodontid (lungless) salamanders have evolved an unusual pheromone delivery system in which the male courtship pheromone is applied to the skin of the female, apparently diffusing through the mucosal-rich epithelia into her superficial capillary system. In Desmognathus ocoee, a plethodontid salamander that uses the diffusion mode of pheromone delivery, we conducted a behavioural bioassay to test a 20-25 kDa molecular weight fraction of the male courtship pheromone: this fraction was effective in increasing female receptivity. The principal component of the D. ocoee pheromone fraction was identified as a 25 kDa protein that had significant sequence similarity with the precursor of a newt reproductive pheromone (a decapeptide termed sodefrin). We termed the principal protein component in the D. ocoee pheromone "Sodefrin Precursor-like Factor" (SPF). SPF also occurs in other plethodontid salamanders, including species of Plethodon, Aneides and Eurycea. Across these species, SPF is a highly variable protein that bears the signature of positive selection. The presence of SPF in distantly related genera suggests that the sodefrin precursor gene has been retained as a courtship signal throughout the evolutionary radiation of plethodontid salamanders. [ABSTRACT FROM AUTHOR]

Human body odour is individually specific and several lines of evidence suggest that to some extent it is under genetic control. There are however numerous other sources of variation, commonly labelled as environmental factors, which are the main aim of this paper. These include: 1) reproductive status, 2) emotional state, 3) diet and 4) diseases. We primarily focus on axillary and genital odours as they have been proposed to have communicative function. We prelusively conclude that a specific diet and some diseases have major impact on variations in human body odour. [ABSTRACT FROM AUTHOR]

Humans produce temporarily stable, genetically mediated odour signatures and possess the ability to recognise, discriminate and identify other people through the sense of smell. The capability of self, gender, kin and non-kin odour recognition plays a role in social interactions. It seems that despite the stability of olfactory cues, the hedonic quality of body odour may vary over time. [ABSTRACT FROM AUTHOR]

The function of scent marking varies not only between species, but also among different age/sex classes within the same species. We conducted a longitudinal study of 26 free-living spotted hyenas to describe the ontogeny of anal gland scent marking (‘pasting') in this species. Males increased the proportional abundance of overmarking between cub and subadult periods, while female pasting remained consistent throughout early development. Pasting was sexually dimorphic in that male cubs pasted more frequently than female cubs, and male subadults countermarked more often than their female peers. By examining the anal pouches of 113 anaesthetized individuals, we also determined that spotted hyenas do not consistently produce paste until their third year. In light of these findings, the potential functions of pasting by juvenile hyenas were discussed. [ABSTRACT FROM AUTHOR]

The spotted hyena (Crocuta crocuta) is a territorial carnivore that lives in highly structured social groups called clans. Individuals of both sexes produce scent in a prominent anal scent gland. Gas-chromatographic analysis of 13 fatty acids and esters in scent profiles from 45 individuals belonging to three social groups demonstrated sufficient variation to suggest that odour may permit individual olfactory recognition. Further, anal scent secretions from members of the same clan are more similar to each other than those from different clans, consistent with the idea of a social group odour. We describe a mechanism involving both scent pasting and dry-pasting behaviour to explain how a group odour label may be concocted from individual scent secretions and how this group label is spread among members of a clan. [ABSTRACT FROM AUTHOR]

Male Saccopteryx bilineata possess a sac-like organ for the storage and display of odoriferous secretion in their front wing membrane. Since males use the scent in agonistic and courtship activities, and compose it from different secretions of distinct sources, like saliva, urine and gland secretion, we hypothesized that multiple information is encoded in the male scent-profile. We expected that the odour profile of males varies seasonally, giving information on male reproductive status. In addition, the odour profile ought to vary between individuals, thus providing the possibility for individual recognition. We repeatedly collected samples from wing-sac liquids of 20 male S. bilineata in five Costa Rican colonies during the mating and non-mating season. Samples were analysed by gas chromatography coupled to mass spectrometry to compare wing-sac contents. Wing-sac odours included various substances such as carboxylic acids, terpenoids and aromatic compounds. Male scent profiles varied (1) between seasons in the relative amount of tetradecanoic and octadecanoic acid, and (2) between individuals in the relative amount of two species-specific substances. These results suggest that the wing-sac liquid of male S. bilineata is indeed a composite trait and may be useful for the simultaneous transfer of multiple information. [ABSTRACT FROM AUTHOR]

Within a limited time after mating, exposure of female rodents to the scent of an unfamiliar conspecific male results in pregnancy termination. Since its discovery in mice, pregnancy block (or the ‘Bruce Effect') has been confirmed in several other murine and microtine rodent species. Adaptive explanations for this behaviour have traditionally focused on advantages to the blocking male, but the suggested benefits to females remain controversial. Consideration of potential female benefits and the implications of female advantage in pregnancy block suggest that this behaviour could evolve with little or no reference to male advantage, and may represent a potential reproductive cost to stud males. [ABSTRACT FROM AUTHOR]

The ability of animals to recognise and discriminate individual conspecifics is a vital feature of mammalian social systems. Genes of the major histocompatibility complex (MHC) have long been recognised to play an important role in influencing chemosensory cues of individual identity. In particular, the profile of urinary volatiles of mice has been related to MHC type, although a mechanism to explain this link has remained obscure. This article aims to review recent developments, which have revealed a new class of MHC-associated chemosignals. These are nine-amino acid peptide ligands bound by MHC class I molecules, which are presented at the cell surface for immune surveillance. In addition to this immune function, these peptides have been found to elicit highly sensitive and specific responses in sensory neurons of both the main olfactory and vomeronasal systems. They have also been shown to convey information about strain identity in biologically relevant contexts. Hence it now appears that there are multiple systems for signalling MHC identity, with distinct features that are likely to be adapted for use in different behavioural contexts. [ABSTRACT FROM AUTHOR]

Sexual orientation influences human olfactory function. Following a brief review of the biological basis of homosexuality, this chapter explores exactly how olfactory function varies as a result of sexual orientation. Three separate areas of research are considered: recent studies on the neural processing of social odorants by heterosexuals and homosexuals; the influence of sexual orientation on the production and perception of body odours; and the influence of female sexual orientation on menstrual synchrony. [ABSTRACT FROM AUTHOR]

Several constituents of human axillary secretions have been proposed as candidate human pheromones, but their influence on human behaviour remains controversial. Here we briefly review the literature on the behavioural effects of candidate compounds, noting that inconsistencies in findings could be due in part to the variation in experimental context and potential lack of ecological validity. We also report results of a pilot study which attempts to overcome these limitations in an ecologically-valid experimental paradigm: a speed-dating event. We tested the effects of 4,16-androstadien-3-one within a single speed-dating evening with 25 female and 22 male participants. We found a significant effect of androstadienone on female judgments of male attractiveness, which is consistent with the proposal that androstadienone could act as a modulatory pheromone in humans. [ABSTRACT FROM AUTHOR]

It has been argued that the great apes have poor olfactory capabilities and that olfactory stimuli convey little useful information for them. Thus odours and scents have little functional significance for the great apes in guiding their behaviour. Part of this belief has been based on the observation that brain volume in those areas dealing with olfactory stimuli relative to other brain areas is greatly reduced in these apes. Moreover, naturalistic observations report little obvious olfactory guided behaviour. We have initiated a programme of work (Project SOAP) investigating the olfactory abilities, and the functions of smell, in the great apes. Here we report an initial study examining whether the western lowland gorilla (Gorilla gorilla gorilla) is able to detect and discriminate between different odours presented on cloths. The study revealed that gorillas can both detect the presence of an odour and discriminate between different odours. An incidental observation demonstrated one trial olfactory guided taste aversion learning which persisted for over 7 weeks. We conclude that gorillas have a functioning olfactory sense that they use in the investigation of their environment, and that olfaction may not be as irrelevant in great apes as has been suggested. [ABSTRACT FROM AUTHOR]

To better understand the relation between form and function in the complex olfactory communication system of the ringtailed lemur (Lemur catta), we integrated observational, experimental, and chemical approaches applied to a population of semi free-ranging animals at the Duke Lemur Center in Durham, North Carolina. Our aim was to examine sex-role reversal in the expression and function of scent marking and unravel the contribution of multimodal components of information transfer, with the unifying framework for all three avenues of our research being that multiplicity of form implies multiplicity of function. [ABSTRACT FROM AUTHOR]

The demonstration of a species-level chemical signal assumes that the same chemical signal serves a similar purpose across the range of the species. Yet, the response to putative chemical signals varies with social setting, environmental conditions, age, sex, and reproductive status of the individuals. Through observations and biological assays with African elephants (Loxodonta africana), we evaluated variation in state behaviors and the likelihood that elephants would perform specific chemosensory event behaviors at our study sites at Addo Elephant National Park South Africa and at Ndarakwai Ranch in Tanzania. We have noted similar time budgets in state behaviors. Post-pubescent (>9 y) elephants showed similar likelihoods in investigating their environment, including conspecific urine and feces. As we pursue the identity of an estrous pheromone, other chemical signals, and developmental patterns, studies with the two populations will be invaluable in assessing the generality of these findings to savanna African elephants. [ABSTRACT FROM AUTHOR]

For most mammals, the ability to detect odours and discriminate between them is necessary for survival. Information regarding the availability of food, the presence of predators and the sex, age and dominance status of conspecifics is odour mediated. Probably because of this extraordinary reliance upon odour cues, mice and rats have developed the ability to learn and remember information associated with olfactory cues as effectively as primates recall visually related cues. As a result, these rodents have become the model of choice to study the neural and cognitive processes involved in olfactory discrimination. In this paper, we describe some of the more ethologically based tasks used in assessing lfactory discrimination and the advantages and disadvantages of the different methodologies employed. [ABSTRACT FROM AUTHOR]

The significance of mane in the lion as a putative source of pheromone is discussed. Since head-rubbing on the tree trunks is as frequent as spraying marking fluid (MF) both MF and mane are likely to leave two osmic signals simultaneously at two neighbouring sites. The chemical analysis of mane reveals the presence of C9-C24 straight-chain branched and unsaturated fatty acids which may play the role of pheromones. The presence of erucic acid in hair is a new observation. Scanning electron micrographs of cross sections of mane hair show "pockets" which could store pheromones. [ABSTRACT FROM AUTHOR]

A major protein component of domestic cat urine is the carboxylesterase family member termed cauxin. Cauxin is secreted into the urine from the proximal straight tubular cells of the kidney, and the level of cauxin excretion is species-, sex-, and age-dependent. Cauxin is excreted in large amounts in the closely related members of the Felidae lineage, the cat (Felis catus), bobcat (Lynx rufus), and lynx (Lynx lynx). Male and female immature cats begin excreting cauxin about 2.5 months after birth, and excretion levels increase with age. In mature cats, cauxin excretion is significantly higher in intact males than in castrated males or female cats. The physiological function of cauxin is to provide species-, sex-, and age-dependent regulation of 2-amino-7-hydroxy-5,5-dimethyl-4-thiaheptanoic acid (felinine) production. Cauxin hydrolyzes the peptide bond of the felinine precursor, 3-methylbutanol-cysteinylglycine, to produce felinine and glycine. The sulfur-containing volatile compounds, 3-mercapto-3-methyl-1-butanol, 3-mercapto-3-methylbutyl formate, 3-methyl-3-methylthio-1-butanol, and 3-methyl-3-(2-methyl-disulfanyl)-1-butanol, are identified as species-specific odorants and candidates of felinine derivatives from the headspace gas of cat urine. These cat-specific volatile compounds may represent pheromones used as territorial markers for conspecific recognition or reproductive purposes by mature cats. The elucidation of cauxin-dependent felinine production provides new evidence for the existence of species-specific odorants and pheromones produced by species-specific biosynthetic mechanisms in mammalian species. [ABSTRACT FROM AUTHOR]

It is increasingly clear that mediation of chemical signals is not the exclusive domain of low molecular volatile or water soluble metabolites. Pheromone binding proteins play an important role in mediating the activity of low molecular weight compounds, while proteins and peptides can also act as information molecules in their own right. Understanding of the role played by proteins in scents has been derived largely from the study of Major Urinary Proteins (MUPs) in the mouse (Mus musculus domesticus) and the rat (Rattus norvegicus). As part of an ongoing programme to explore the diversity and complexity of urinary proteins in rodents, we have applied a proteomics-based approach to the analysis of urinary proteins from a wider range of rodents. These data suggest that many species express proteins in their urine that are structurally similar to the MUPs, although there is considerable diversity in concentration, in sexual dimorphism and in polymorphic complexity. This is likely to reflect a high degree of species-specificity in communication and the information that these proteins provide in scent signals. [ABSTRACT FROM AUTHOR]

A relatively small number of mammalian pheromones has been identified, in contrast to a plethora of known insect pheromones, but two remarkable Asian elephant/insect pheromonal linkages have been elucidated, namely, (Z)-7-dodecen-1-yl acetate and frontalin. In addition, behavioral bioassays have demonstrated the presence of a chemical signal in the urine of female African elephants around the time of ovulation. Our search for possible ovulatory pheromones in the headspace over female African elephant urine has revealed for the first time the presence of a number of known insect pheromones. This search has been facilitated by the use of a powerful new analytical technique, automated solid phase dynamic extraction (SPDE)/GC-MS, as well as by novel macros for enhanced and rapid comparison of multiple mass spectral data files from Agilent ChemStation^ˆ. This chapter will focus on our methodologies and results, as well as on a comparison of SPDE and the more established techniques of solid phase microextraction (SPME) and stir bar sorptive extraction (SBSE). [ABSTRACT FROM AUTHOR]

Current investigations of mammalian chemical signals are providing biologically useful information. Precision of profiling data has become substantially improved due to better sampling methodologies, selective detection techniques and vastly improved mass-spectrometric instrumentation. This, in turn, facilitates the use of powerful chemometric methodologies in evaluation of large data sets and a future integration of volatile profiling data into the systems biology knowledge. [ABSTRACT FROM AUTHOR]