Discrimination between individuals by scent in Lemur fulvus

When a captive Lemur fulvus is habituated to the scent of another L. fulvus by repeatedly presenting it with that individual's scent, and is then presented with the scent of a second individual, the amount of sniffing of the scents increases, indicating that it discriminated between the scents of the two individuals. The two individuals' scents were significantly discriminated in eight of eleven different combinations of scent receiver and pair of scent donors. The two scent donors were always of the same sex and subspecies, and they could be discriminated by members of their own or of another sex or subspecies.     

野捕和圈养繁殖雄性马麝行为格局的比较

采用焦点取样和连续记录法,对甘肃兴隆山麝场圈养雄性马麝(Moschus sifanicus)进行行为取样,比较野捕和圈养繁殖雄性马麝的行为差异,并对雄麝在交配季节和非交配季节的行为时间分配进行分析.结果表明,由于圈养环境和管理模式相同,野捕和圈养繁殖马麝的总体行为格局类似,其时间和能量分配格局无本质差异,但由于幼年期的抓捕、人工哺乳及圈养方式等对其行为发育的影响,野捕雄麝的冲突行为表达强度显著高于驯产雄麝(P＜0.05).和非交配季节相比,雄麝在交配季节的静卧行为持续时间较少(P＜0.05),运动性增加(P＜0.05),摄食(P＜0.05)和反刍减少(P＜0.05),蹭尾标记及粪尿标记行为持续时间较长,增加了信息标记强度,且对相关的环境探究和尾阴探究等信息收集行为相应增加,但差异均不显著(P＞0.05).     

Sociosexual development,pair bond formation,and mechanisms of fertility suppression in female cotton-top tamarins (Saguinus oedipus oedipus)

The effect of various social environments on sociosexual behavior was examined in six young female cotton-top tamarins (Saguinus oedipus oedipus) and in three established breeding females. Behavioral observations and hormonal samples were collected on young females while they were living with their families, when they were isolated from conspecifics, and after they were paired with an unrelated male. While living with the family, all females showed a suppression of fertility and low frequencies of sociosexual behavior. Following removal from the family, isolated females displayed an increase in rate of scent marking and an increase in hormonal levels. When young females were paired with males, they were exposed to scent secretions from their natal families, from an unfamilar family, and from a control for a total of 24 weeks. After pairing, hormonal levels increased dramatically, and ovarian cyclicity began. An increase in sociosexual behavior and elevated levels of scent marking accompanied this physiological change. Newly paired females had higher rates of affiliative behavior and scent marking than did established breeding females. However, both newly paired and established breeding males were more likely to initiate contact, grooming bouts, and social sniffing than were females. Time to first ovulation was later in females who were exposed to scent secretions from their natal families than it was in those females given a control for the first 8 weeks following pairing. No female conceived during exposure to scent secretions. However, once normal ovarian cycling had begun or a pregnancy was established, exposure to scent secretions had no effect. Thus, the social environment influences the fertility, sociosexual behavior, and pair bond formation of cotton-top tamarins. In addition, chemical stimuli found in the scent secretions produced by the natal family are most likely involved in reproductive suppression.     

Effects of sex hormones and gender on attraction thresholds for volatile anal scent gland odors in ferrets

Body odors contribute to mate recognition and sexual partner preference in many mammals, including ferrets. We used a habituation/dishabituation procedure to test whether sex steroid hormones influence whether ferrets will approach and investigate different concentrations of volatile anal scent gland odors from male and female conspecifics. When tested with high concentrations of anal scent gland secretions in oil vehicle, gonadectomized male and female ferrets that received no sex steroids reliably discriminated anal scents from male and female conspecifics. This discrimination most likely reflects gender recognition rather than individual recognition because gonadectomized, sex steroid-treated ferrets discriminated between anal scents of males and females but not between anal scents of individual males or females. Treatment with either the estrogen receptor agonist, estradiol benzoate (EB), or the androgen receptor agonist, 5-alpha dihydrotestosterone proprionate (DHTP), increased investigation of low concentrations of anal scent by gonadectomized ferrets. These data suggest that ferrets could use anal scent gland secretions in mate recognition and that seasonal increases in circulating sex steroid hormones increase ferrets' responsiveness to low concentrations of these odors.     

Himalayan musk deer (Moshcus leucogaster) behavior at latrine sites and their implications in conservation

Elusive species often use latrines which also serves as communication and information hubs. Thus, studying behavior at latrines may provide critical insights into the species’ ecology and behavior. While it is established that musk deer use latrines for defecating, very little is known about the endangered Himalayan musk deer (Moschus leucogaster) and their latrines. We examined musk deer behavior from the various video clips lasting 238 min altogether, captured at latrine sites during both breeding and non‐breeding seasons in the Annapurna Conservation Area of Nepal. A total of 428 visits by musk deer and 479 behavioral events by them were captured. We constructed an ethogram to describe musk deer behavior and compared behavior across individuals and sex using parametric and non‐parametric tests. We found that musk deer are crepuscular and nocturnal animals. Both male and female musk deer repeatedly and independently visited shared latrine sites as well as exclusively used latrine sites. The proportion of male musk deer visited latrine sites were significantly higher than that of female musk deer. Hence, male musk deer were found more active (>2 times) than females during both seasons. The most frequently observed behavioral activities at the latrine sites were defecating, sniffing and browsing, followed by scrapping and covering, and ignoring the latrine sites. The defecating and sniffing activity were performed throughout breeding and non‐breeding seasons to establish communication among peers and to claim territory. Based on the behaviors observed at the latrine sites, we can presume that Himalayan musk deer likely use latrines to convey various messages, including personality, maturity, sexual status, and territory marking among conspecifics. These findings of this study can be used for the conservation of musk deer in its natural habitat and replicated in captivity to enhance breeding performance that improves long‐term conservation prospects for this species.     

Scent may signal fighting ability in male Iberian rock lizards

Intrasexual competition favours the evolution of conspicuous fighting ability badges. However, in spite of the fact that chemoreception is important in sexual selection of many animals, such as lizards, the role of chemical signals in males' contests is relatively unknown. Here, we show that proportions of cholesterol in femoral gland secretions of male Iberian rock lizards were related to their body size (which confers a competitive advantage in fights). Males discriminated chemically and responded aggressively to cholesterol stimuli presented on swabs. Moreover, we experimentally increased cholesterol in the scent of males, and staged encounters in neutral cages between two unfamiliar and size-matched males. Focal males lost more agonisitic interactions against males manipulated with cholesterol than in control tests. We suggest that differences in scent composition may reliably signal fighting ability in many lizard species, which would help to avoid the costs of fighting.     

Species and subspecies specificity in urine and scent marks of saddle-back tamarins (Saguinus fuscicollis)

Saguinus fuscicollisproduces scent marks which consist mainly of a mixture of urine and the secretions of circumgenital scent glands. The present study investigates the ability of saddle-back tamarins to discriminate between scent material from conspecifics and corresponding material from other species and to differentiate material from two subspecies of Saguinus fuscicollis.When choices between urine samples from conspecifics and from guinea pigs and choices between urine samples from conspecifics and from common marmosets were offered, the tamarins investigated samples from conspecifics more frequently. Similar responses were obtained when choices between scent marks from saddle-back tamarins and from common marmosets and between scent marks from saddle-back and red-chested moustached tamarins were offered. The tamarins also discriminated between scent marks and between extracts of scent marks from Saguinus f. fuscicollisand Saguinus f. illigeri.In these choice tests, subjects of both subspecies tended preferentially to investigate material from Saguinus f. fuscicollis.The results of these studies show that urine and scent marks contain chemical cues on which recognition of conspecifics can be based. Moreover, the scent marks of closely related subspecies also offer cues which could enable the tamarins to discriminate between them.     

Responses to oral gland scents from different males in Columbian ground squirrels

Acrylic cubes carrying oral gland scents from strange, neighbouring, and resident male Columbian ground squirrels (Spermophilus columbianus), plus a cube with no scent, were presented near the home burrows of squirrels in the field. Adult males and adult females sniffed scented cubes longer than unscented cubes, sniffed cubes with scent from other (strange and neighbouring) males longer than cubes with the resident male's own scent, and sniffed cubes with scent from strange males longer than cubes with scent from neighbouring males. Males also scent-marked the cubes on a number of occasions; differences in the frequency with which the cubes were marked followed the same pattern. It thus appears that adult Columbian ground squirrels can recognize familiar as opposed to unfamiliar males, and may also be able to determine individual identity, through oral gland scent. An ability to distinguish familiar from unfamiliar males by scent could be advantageous in facilitating differential treatment of wandering strange males versus established neighbours.     

布氏田鼠在不同光周期下对陌生个体尿液和粪便的气味辨别

研究了成年布氏田鼠在10min内,对不同光照周期下（长光照：LD;短光照：SD）陌生雌／雄个体尿液和粪便两种单一个体气味源的气味行为反应,实验发现：所有雌雄被试鼠对LD气味源比SD气味源表现出更多的嗅闻行为。LD和SD被试鼠对同性／异性尿液气味的嗅闻行为没有表现出明显的差别,但LD被试雄鼠对陌生雌鼠粪便的嗅闻频次显多于SD被试雄鼠,从嗅闻行为特征量（嗅闻行为占所有行为的百分比）来看,所有LD和SD被试雌,雄鼠对尿液的嗅 明显多于粪便,除SD粪便气味外,被试鼠对异性气味源的嗅闻明显多于同性,实验结果表明：作为两种个体气味源,尿液和粪便都带有季节性信息,而且是具有性别特性的。异性的个体气味源比同性的个体气味源更具吸引力;长光照动物的个体气味比短光照动物的气味更具吸引力。     

Scent marking as resource defense by female Lemur catta

Because ring-tailed lemurs (Lemur catta) are a female-dominant, female-philopatric species in which the females provide the majority of parental care and troop defense, resource defense is a possible function of female lemur scent marking. To test this hypothesis, I conducted three studies. First, I presented captive, individually housed females with a series of samples of female scent, each from a different female, to determine whether they would respond to those samples and discriminate between them. Second, I reanalyzed data from a focal animal study of four females in two adjacent troops in Berenty Reserve, Madagascar, to determine female marking rates before, during, and after the mating season, and to clarify the relationship among positions of feeding, intertroop defense, and scent marking. The third study was based on ad libitum observations of the sniffing and marking behavior of a troop in Berenty Reserve during a year when they traveled far out of their home range. The females in study 1 investigated female scent samples but provided no evidence that they discriminated between them. In study 2 the wild females marked throughout the study and did not limit their marking to the mating season. They deposited significantly more of their marks in a zone of confrontation with adjacent troops, where they also did the majority of their feeding, and they increased their rate of marking during agonistic intertroop confrontations. The females determined the positions of their scent marks and deposited the first mark in the majority of countermarking sequences. When the females traveled out of their defended range in study 3, they significantly decreased their rate of marking and increased their rate of sniffing spots but not marking them. All evidence gathered so far supports the hypothesis that one function of female ring-tailed lemur scent marking is to provide intergroup information that is then used to reinforce the border of the defended resource.     

The role of aromatization in androgen stimulation of gerbil scent marking

The androgen dependent scent marking behavior of male Mongolian gerbils (Meriones unguiculatus) can be stimulated after castration by either testosterone or estrogen, but not by dihydrotestosterone (DHT). To determine if DHT fails to evoke scent marking because it cannot be aromatized to form an estrogen, two other nonaromatizable androgens, 1α-methyltestosterone and 6α-fluorotestosterone, were studied. 6α-Fluorotestosterone and its propionate ester stimulated scent marking in castrated male gerbils as effectively as testosterone and its ester did. Hence, an androgen's aromatizability does not determine its ability to influence gerbil scent marking behavior.     

Epethelial Presence of Trueperella pyogenes Predicts Site-Level Presence of Cranial Abscess Disease in White-Tailed Deer (Odocoileus virginianus)

Cranial/intracranial abscess disease is an emerging source of significant mortality for male white-tailed deer (Odocoileus virginianus). Most cases of cranial/intracranial abscess disease are associated with infection by the opportunistic pathogen Trueperella pyogenes although the relationship between the prevalence of the bacteria and occurrence of disease is speculative. We examined 5,612 hunter-harvested deer from 29 sites across all physiographic provinces in Georgia for evidence of cranial abscess disease and sampled the forehead, lingual, and nasal surfaces from 692 deer. We used polymerase chain reaction (PCR) to determine presence of T. pyogenes from these samples. We found T. pyogenes prevalence at a site was a predictor for the occurrence of cranial abscess disease. Prevalence of T. pyogenes did not differ between samples from the nose or tongue although prevalence along the forehead was greater for males than females (p = 0.04), particularly at sites with high occurrence of this disease. Socio-sexual behaviors, bacterial prevalence, or physiological characteristics may predispose male deer to intracranial/cranial abscess disease. Determination of factors that affect T. pyogenes prevalence among sites may help explain the occurrence of this disease among populations.     

圈养雄獐领域行为和粪便睾酮水平变化的关系

2011年8月到2012年4月间,在上海市浦东新区华夏公园獐重引入试点,采用目标取样、扫描取样和全事件记录法,对圈养条件下6只成体雄獐(Hydropotes inermis)的6种领域行为进行观察,并利用放射免疫分析法(RIA)测定雄獐粪便中的睾酮水平变化.结果表明,雄獐的许多领域行为发生频次表现出明显的月间变化,包括打斗、威胁、取代、追逐和粪尿标记;擦额标记行为频次虽月间差异不显著,但与其他领域行为一样在11月份出现频次峰值.发情期(2011年10月～2012年1月)和非发情期(2011年9月、2012年2～4月),打斗、威胁、粪尿标记和擦额标记行为发生频次差异显著;取代和追逐行为频次差异不显著.6种领域行为的发生频次均在发情期明显高于非发情期.粪便睾酮含量在发情期和非发情期差异显著,发情期明显高于非发情期,其含量在12月份达到峰值(51.16±9.85) ng/g.雄獐的威胁、擦额标记、粪尿标记和打斗行为发生频次与睾酮水平呈显著的正相关性,而取代和追逐行为与睾酮水平变化不具有显著相关性.     

Neuroendocrine response to female ovulatory odors depends upon social condition in male common marmosets, Callithrix jacchus

Male mammals show rapid behavioral and hormonal responses to signals from sexually receptive females. However, rapid endocrine responses to female signals have not been observed in a nonhuman primate. Here, we tested the behavioral and hormonal response of male common marmosets (Callithrix jacchus) to isolated scent secretions from ovulatory females or to vehicle control scent. Fifteen males were tested in their home cage for behavioral and hormonal responses. These males showed increased investigative and arousal behaviors to the ovulatory scent compared to the vehicle scent. Time sniffing the scent substrate and the duration of erections were significantly elevated in relation to the vehicle scent. Thirty minutes after presentation of ovulatory scent, males showed a significant increase in testosterone compared to the vehicle, but there was no difference in cortisol values. To better control for scent presentation, 15 additional males were tested under a controlled scent exposure. Current social housing condition influenced the male's testosterone response to the ovulatory scent. Single and paired males showed significant increases in testosterone levels with the ovulatory scent but did not increase cortisol levels. Single males also showed the highest change in testosterone with the ovulatory scent, but fathers showed no changes. These results indicate that a rapid hormonal response to sexually arousing cues occurs in marmosets, and the data suggest that a male's social condition influences how he responds to sexually relevant cues.     

Vitamin E supplementation increases the attractiveness of males' scent for female European green lizards

Background

In spite that chemoreception is important in sexual selection for many animals, such as reptiles, the mechanisms that confer reliability to chemical signals are relatively unknown. European green lizards (Lacerta viridis) have substantial amounts of α-tocopherol ( = vitamin E) in their femoral secretions. Because vitamin E is metabolically important and can only be attained from the diet, its secretion is assumed to be costly. However, its role in intraspecific communication is unknown.

Methodology/Principal Findings

Here, we experimentally show that male European green lizards that received a dietary supplement of vitamin E increased proportions of vitamin E in their femoral secretions. Furthermore, our experiments revealed that females preferred to use areas scent marked by males with experimentally increased vitamin E levels in their secretions. Finally, female preferences were stronger when vitamin E differences between a pair of males'' secretions were larger.

Conclusions/Significance

Our results demonstrate that female green lizards are able to discriminate between males based on the vitamin E content of the males'' femoral secretions. We suggest that the possible cost of allocating vitamin E to secretions, which might be dependent on male quality, may be a mechanism that confers reliability to scent marks of green lizards and allows their evolution as sexual signals.     

Sexual behaviour and its olfactory control in the desert woodrat (Neotoma lepida lepida)

In studies 1 and 2 nine pairs of desert woodrats (Neotoma lepida lepida) were observed for copulatory behaviour when the female was in a state of naturally occurring oestrus (study 1) and following ovariectomy and oestrogen and progesterone replacement (study 2). Males and females respond in a similar way under conditions of natural and hormone-induced oestrus. Males show a consummatory pattern involving multiple mounts and ejaculations, with ejaculations occurring after single intromissions. Females show the lordosis reflex accompanied by hop-and-dart and ear-wiggling responses. In addition, both sexes show appetitive precopulatory behaviours; the male emits an audible rasping vocalization as he trails and mounts the female, following a period of intense sniffing of the female's anogenital region. The female also frequently approaches and sniffs the male. In study 3, the role of female odours in the sexual behaviour of the male was examined in eight of the nine pairs used in studies 1 and 2. This was done by applying to the anogenital region of ovariectomized females a combination of urine and vaginal secretions taken from familiar and unfamiliar, and oestrogen-primed or non-oestrogen-primed females. The results show that odours from oestrogen-primed females are not sufficient to elicit male sexual behaviour, if the female is not sexually active. In study 4 the eight males were tested for their preferences for urine and vaginal secretion odours taken from females in different reproductive states and applied to cotton swabs. These males spent more time sniffing unfamiliar oestrous odours than unfamiliar non-oestrous odours and more time sniffing oestrous odours from a familiar female over those taken from an unfamiliar female.In study 5, 12 sexually active males were tested with oestrogen-primed females before and after either olfactory bulb removal or sham-surgery. Bulbectomized animals ceased copulating with females although females showed precopulatory approaches.Taken together, these studies suggest that normal sexual behaviour in the male woodrat requires that the female both possess the attractive odours (of oestrus) and that she engage in appetitive precopulatory behaviour.     

Disentangling demographic effects of red deer on chamois population dynamics

Investigating the impact of ecological factors on sex‐ and age‐specific vital rates is essential to understand animal population dynamics and detect the potential for interactions between sympatric species. We used block count data and autoregressive linear models to investigate variation in birth rate, kid survival, female survival, and male survival in a population of Alpine chamois Rupicapra rupicapra rupicapra monitored over 27 years within the Stelvio National Park, Central Italian Alps, as function of climatic variables, density dependence, and interspecific competition with red deer Cervus elaphus. We also used path analysis to assess the indirect effect of deer abundance on chamois growth rate mediated by each demographic parameter. Based on previous findings, we predicted that birth rate at [t] would negatively relate to red deer abundance at year [t − 1]; survival rates between [t] and [t + 1] would negatively relate to red deer abundance at year [t − 1] and to the interactive effect of winter precipitation at [t + 1] and chamois density at [t]. Our results showed that birth rate was positively related to spring–summer precipitation in the previous year, but this effect was hampered by increasing red deer abundance. Kid and female survival rates were negatively related to the combined effect of chamois abundance and winter precipitation. Male and female survival rates were negatively related to lagged red deer abundance. The path analysis supported a negative indirect effect of red deer abundance on chamois growth rate mediated by birth rate and female survival. Our results suggest that chamois population dynamics was largely explained by the synergistic effect of density dependence and winter harshness, as well as by interspecific competition with red deer, whose effects were seemingly stronger on the kid–female segment of the population.     

Mice recognize recent urine scent marks by the molecular composition

Male mice mark the territory with urine scent marks that are frequently renewed to maintain the territory ownership. We measured the response of male mice to small spots of urine deposed either 0, 5, 11, 22, 45, 90 min, or 24 h before testing and show that mice loose interest in sniffing scent marks as they become older and older. We asked what scent features tell a mouse how recent a scent mark is, and therefore, we studied the molecule-to-behavior relationship by correlating 6 behavioral variables--the number of sniffing acts, the latency to the first sniff, the number of urine marks, the latency to the first mark, the area of the marks, and the number of fecal pellets-to 2,4-dehydro-exo-brevicomin, linalool, 2-sec-butyl-4,5-dihydrothiazole, 2,4-dimethylphenol, 4-ethylphenol, and 6,10-dimethyl-5,9-undecadien-2-one released from urine spots over the time, identified, and quantified by gas chromatography and mass spectrometry. Canonical correlation between the molecular and the behavioral principal components was strong (R(1) = 0.96, P = 0.026). The principal component based on 2,4-dehydro-exo-brevicomin, linalool, and 2-sec-butyl-4,5-dihydrothiazole correlated negatively with countermarking and positively with the sniffing behavior, suggesting a semantic feature of fresh male mouse urine.     

Scent-marking in ring-tailed lemurs: Responses to the introduction of “foreign” scent in the home range

In three sets of experiments, a group of captive Ring-tailed lemurs ranging at liberty were presented with sticks scent-marked with their own scent, or with scent from unrelated animals or unmarked sticks. The results from experiments which involved a choice between scents indicated stronger responses, in terms of greater intensity of scent-marking to scent from “strange” animals. In the experiment where individual scents were presented one at a time, the length of time spent sniffing was greater for “strange” scent but this did not transfer to additional scent-marks. Most of the responses were elicited from males in the group and involved wrist-marking only, but timing of experiment influenced both responses and type of scent-mark probably in relation to the onset of oestrus. The role of scent-marking and the concept of group scent are also discussed.     

Fecal Volatile Organic Ccompound Profiles from White-Tailed Deer (Odocoileus virginianus) as Indicators of Mycobacterium bovis Exposure or Mycobacterium bovis Bacille Calmette-Guerin (BCG) Vaccination

White-tailed deer (Odocoileus virginianus) serve as a reservoir for bovine tuberculosis, caused by Mycobacterium bovis, and can be a source of infection in cattle. Vaccination with M. bovis Bacille Calmette Guerin (BCG) is being considered for management of bovine tuberculosis in deer. Presently, no method exists to non-invasively monitor the presence of bovine tuberculosis in deer. In this study, volatile organic compound profiles of BCG-vaccinated and non-vaccinated deer, before and after experimental challenge with M. bovis strain 95–1315, were generated using solid phase microextraction fiber head-space sampling over suspended fecal pellets with analysis by gas chromatography/mass spectrometry. Chromatograms were processed using XCMS Online to characterize ion variation among treatment groups. The principal component scores resulting from significant (α = 0.05) ion responses were used to build linear discriminant analysis models. The sensitivity and specificity of these models were used to evaluate the feasibility of using this analytical approach to distinguish within group comparisons between pre- and post-M. bovis challenge: non-vaccinated male or female deer, BCG-vaccinated male deer, and the mixed gender non-vaccinated deer data. Seventeen compounds were identified in this analysis. The peak areas for these compounds were used to build a linear discriminant classification model based on principal component analysis scores to evaluate the feasibility of discriminating between fecal samples from M. bovis challenged deer, irrespective of vaccination status. The model best representing the data had a sensitivity of 78.6% and a specificity of 91.4%. The fecal head-space sampling approach presented in this pilot study provides a non-invasive method to discriminate between M. bovis challenged deer and BCG-vaccinated deer. Additionally, the technique may prove invaluable for BCG efficacy studies with free-ranging deer as well as for use as a non-invasive monitoring system for the detection of tuberculosis in captive deer and other livestock.