雄性大熊猫对化学信息行为反应的年龄差异

化学通讯对哺乳动物的生存和繁殖起着重要作用。研究了雄性大熊猫(Ailuropoda melanoleuca)对同伴个体尿液气味行为反应的发育模式。结果显示,在成年雌性个体的尿液气味刺激下,雄性个体表现显著多的嗅闻行为和嗅闻/舔舐环境行为,但是嘶咬气味刺激物的行为明显减少。在雌性个体的尿液气味刺激下,不同年龄段的雄性个体行为表现不同,成年雄性个体表现较亚成年和幼年个体显著多的舔舐行为。此外,成年个体和亚成年个体均表现较多的嗅闻/舔舐环境行为,而幼年个体则无该行为表现。幼年个体较成年和亚成年个体表现显著多的气味涂抹行为,而且嘶咬气味刺激物的时间较亚成年个体显著多。幼年个体和亚成年个体对雌性和雄性个体尿液气味刺激的行为反应不存在显著差异。研究结果表明,雄性大熊猫对同种个体尿液中化学信息的行为反应呈现出年龄差异。     

圈养小熊猫繁殖行为变化及繁殖行为对策

In order to investigate the change of reproductive behaviors and understand reproductive strategies of both male and female red pandas, one-year behavioral observation was conducted through the focal sampling method in the Chengdu Research Base of Giant Panda Breeding from December 1999 to November 2000. Our results indicated that reproductive behaviors showed significant differences between the estrous and non-estrous seasons. Frequencies of the rubbing anogenital, sniffing and licking marking were much higher in estrus than in non-estrus. Bleating only appeared in the estrus and can be regarded as an estrous indicator.The result also demonstrated that both male and females applied different reproductive behavioral strategies. Frequencies of activity, rubbing anogenital, licking and sniffing marking, and bleat were much higher in the male than in the female. However, those of resting and investigating were much lower in the male than in the female. This indicated that the male was more active than the female during the estrus and might imply that the male acts mainly as an estrous message sender, and the female as a message receiver in the estrous season.     

Reproductive Strategies in Lemur catta: Balance Among Sending,Receiving, and Countermarking Scent Signals

Our goal is to go deep into behavioral olfactory strategies possibly used by ring-tailed lemurs in reproductive competition and to shed some light on the function of female scent marks deposited outside the breeding season. We followed 16 captive adults at the Pistoia Zoo (Tuscany, Italy) for > 1,500 h from May 1997 to March 1999. Male direct and indirect olfactory investigation on females showed complementary distributions, the former peaking during the breeding and the latter during the birth season. Males are thus able to monitor female reproductive conditions throughout the whole year. During the birth season there was an increase of female genital marking. The olfactory advertisement probably guarantees that the extremely brief estrus does not remain unnoticed and allows male intrasexual competition a long period to operate. Male indirect olfactory monitoring and countermarking on female signals peaked during the birth season, which suggests that male intrasexual competition is achieved both by getting female chemical messages and by concealing them from other males. Female countermarking on other female genital marks peaked during the breeding season. High-ranking females had higher frequencies of countermarking than those of low-ranking females, which suggests that the advantage of obliterating scent signals of other females is greater than the disadvantage of revealing one's own reproductive condition.     

Social Behaviour of Domestic Cats (Felis lybica f. catus L.): a Study of Dominance in a Group of Female Laboratory Cats

The behaviour of a group of female domestic cats (n = 10) under laboratory conditions is described. Behavioural observations were made on a total of 20 days during a 3-month period; only frequencies were recorded. Analysis of the winner/loser matrix revealed a linear rank order. This rank order correlated with several variables. The higher the rank, the more offensive threats a cat emitted overall, and the more defensive threats it received overall; within a pair, the higher-ranking cat displayed more offensive threats, whereas the lower-ranking cat displayed more defensive threats. The higher a rank, the more bouts of social licking a cat emitted overall, and the more bouts of social sniffing and social rubbing it received overall; within a pair, the higher-ranking cat tended to show more social licking, whereas the lower-ranking cat showed more social sniffing. The higher the rank, the more time a cat tended to spend on the floor, and the less time it spent in a 16-compartment complex; the further animals were apart in rank, the smaller were the proximity scores between them. Finally, higher-ranking cats tended to gain weight, whereas lower-ranking cats tended to lose weight. These data suggest that the concept of dominance may be applied to this group of cats. It is discussed whether the observed rank order is specific for indoor conditions under which the cats were living. The role of social licking is also discussed.     

The relationship between female rank and reproductive parameters of the ringtailed lemur: a preliminary analysis

We used data from a 13-year field study of wild ringtailed lemurs to analyze the relationship between female rank and reproductive parameters. In medium and small groups there were no significant differences in birth rate, infant mortality rate, and the number of surviving infants between the female rank categories. On the other hand, in large sized groups low-ranked females had a smaller number of surviving infants than middle-ranked females. This suggests that in large sized groups, within-group competition lowered the values of reproductive parameters of low-ranked females. On the other hand, high and low-ranked females of small sized groups tended to have a smaller number of surviving infants than high-ranked females of medium sized groups and middle-ranked females of large sized groups. Between-group competition should lower the values of their reproductive parameters. In sum, these results fit the expectation from Wrangham’s (1980) inter group feeding competition model.     

The effects of dominance rank and group size on female lifetime reproductive success in wild long-tailed macaques,Macaca fascicularis

Demographic changes were recorded throughout a 12-year period for three social groups ofMacaca fascicularis in a natural population at Ketambe (Sumatra, Indonesia). We examined the prediction that females' lifetime reproductive success depended on dominance rank and group size. Average birth rate was 0.53 (184 infants born during 349 female years). For mature females (aged 8–20 yr) birth rate reflected physical condition, being higher in years with high food availability and lower in the year following the production of a surviving infant. High-ranking females were significantly more likely than low-ranking ones to give birth again when they did have a surviving offspring born the year before (0.50 vs 0.26), especially in years with relatively low food availability (0.37 vs 0.10). Controlled comparisons of groups at different sizes indicate a decline in birth rate with rroup size only once a group has exceeded a certain size. The dominance effect on birth rate tended to be strongest in large groups. Survival of infants was rank-dependent, but the survival of juveniles was not. There was a trend for offspring survival to be lower in large groups than in mid-sized or small groups. However, rank and group size interacted, in that rank effects on offspring survival were strongest in large groups. High-ranking females were less likely to die themselves during their top-reproductive years, and thus on average had longer reproductive careers. We estimated female lifetime reproductive success based on calculated age-specific birth rates and survival rates. The effects of rank and group size (contest and scramble) on birth rate, offspring survival, age of first reproduction for daughters, and length of reproductive career, while not each consistently statistically significant, added up to substantial effects on estimated lifetime reproductive success. The group size effects explain why large groups tend to split permanently. Since females are philopatric in this species, and daughters achieve dominance rank positions similar to their mother, a close correlation is suggested between the lifetime reproductive success of mothers and daughters. For sons, too, maternal dominance affected their reproductive success: high-born males were more likely to become top-dominant (in another group). These data support the idea that natural selection has favored the evolution of a nepotistic rank system in this species, even if the annual benefits of dominance are small.     

Female rank and reproductive success among arashiyama B Japanese macaques (Macaca fuscata)

Five hypotheses that related female rank and reproductive success were tested in an intact troop of free-ranging, provisioned, Japanese macaques. The hypotheses stated that high-ranking females (1) begin parturition earlier in life than low-ranking females; (2) produce more offspring than low-ranking females; (3) give birth during some optimal time during the birth season to a greater extent than low-ranking females; (4) experience less infant mortality than low-ranking females;and (5) more frequently produce male offspring, while low-ranking females more frequently produce female offspring. A statistical analysis of the data which included three birth seasons and 55 adult females and 34 pubescent females, all of known age, rank, and matrifocal membership in the Arashiyama B troop, revealed few significant results. An association was found between the rank of the matrifocal unit and the age of first birth. However, the relationship was the reverse of hypothesis 1, i.e., females of the lower-ranking matrifocal units began parturition earlier than females of higher-ranking matrifocal units. Therefore, in this troop of Japanese monkeys— where alternative feeding strategies existed— there was little association between female rank and reproductive success.     

Male-Induced Sociosexual Behavior by Vaginal Secretions in Macaca arctoides

Odor communication in Old World monkeys and apes is controversial, because most females have evolved visual and behavioral cues to signal fertility, e.g., sexual swellings. Female stump-tailed macaques (Macaca arctoides) do not have swellings, and mediation of chemical communication likely occurs because males engage in sexual behavior mostly throughout the periovulatory phase of the menstrual cycle. We tested whether vaginal secretions from different cycle phases, with saline solution as a control, promote changes in the frequency of male genital exploration, copulation, and coercive behavior toward females different from the donors, while female donors were apart from the group. Males explored more female genitals when exposed to follicular, periovulatory, and early luteal secretions in comparison to saline or menstrual or late luteal secretions. The increase in coercive behavior after exposure to follicular and periovulatory secretions most likely was a male response to the lack of cooperation of target females in engaging in copulation, as the latter were not receptive during the tests. The strength of male response to vaginal secretions varied significantly as a result of individual variability between donor females, yet the variability does not correlate either to dominance rank or to female age. Exploratory behavior of males correlates significantly with their social rank. Our results suggest that vaginal secretions are among the cues that male Macaca arctoides use to acknowledge the reproductive status of females in the absence of visual 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.     

Maternal and paternal care in the rock cavy,Kerodon rupestris,a South American hystricomorph rodent

The maternal and paternal behavior of Kerodon rupestris was examined. Quantitative differences between fathers and mothers and between mothers raising young with fathers present and with fathers absent were assessed. Growth rates of young raised by paired females and by lone females were compared. The male provides direct paternal care to the young by engaging in allogrooming, sniffing, and huddling. There is no significant difference between the sexes in the amount of contact promoting behavior given to the offspring, nor are the sexes significantly different in the amount of exploratory sniffing of the offspring. When the male is absent, the female spends a greater amount of time in contact with the young. Young raised by lone females gained significantly more weight than young raised by paired females. The suggestion that indirect paternal care acts to reduce female aggression to the young and relieve the energy expenditure burden of the female is discussed. The results indicate that social experience is gained at the expense of physical nurturing when the male is present.     

Olfactory communication among Costa Rican squirrel monkeys: a field study.

Behaviors with a possible role in olfactory communication among troop members were investigated as part of a field study on the reproductive and foraging ecology of squirrel monkeys (Saimiri oerstedi) in Costa Rica. All age classes engaged in the olfaction-related behaviors. Apart from olfactory investigation of female genitals by males during the mating season, no other potential olfaction-related behavior (urine wash, branch investigation, rump, chest, back rub and sneeze) exceeded 1% of mean behavioral samples. Assessment of reproduction condition appears to be the primary function of such olfactory investigation of the female genital region. The primary function of urine washing is suggested to be the general communication of reproductive status, possibly facilitating reproductive synchrony. Sneezing, rump, back and chest rubbing do not appear to deposit substances active in olfactory communication.     

Olfactory discrimination in the western lowland gorilla, Gorilla gorilla gorilla

The olfactory abilities of great apes have been subject to little empirical investigation, save for a few observational reports. This study, using an habituation/dishabituation task, provides experimental evidence for a core olfactory ability, namely, olfactory discrimination, in the gorilla. In Experiment 1, six zoo-housed western lowland gorillas were individually presented with the same odour on four trials, and with a novel odour on the fifth trial. Odours (almond and vanilla) were presented on plastic balls, and behavioural responses of sniffing and chewing/licking the balls were recorded. A second experiment presented the same odour on four trials and no odour on the fifth to examine whether any dishabituation was due to the presence of a new odour or the absence of the familiar odour. Gorillas habituated their behaviour with repeated presentation of the same odour, but dishabituated, i.e. increased sniffing and chewing/licking, when presented with the novel odour. No dishabituation was noted when using water as the stimulus across all trials or when used as the novel odour. Overall, results show that gorillas are able to discriminate between odours.     

A preliminary study of olfactory behavior of captiveLemur coronatus during the breeding season

The olfactory behavior of a captive population of crowned lemurs (Lemur coronatus)was studied during their annual breeding season in order to investigate its possible role in the fine-tuning of mating synchrony after photoperiodic initiation of reproductive activity. The frequencies of five stereotyped olfactory behavior patterns were recorded in four male-female groups during 315 1-hr observation sessions between October and March. The mean total scent-marking frequency of all males was positively correlated with their mean testicular size. Male anogenital-, head-, and allomarking frequencies decreased during the breeding season, whereas hand-marking frequencies remained constant. Male head-marking increased significantly in the 5 days preceding female vaginal estrus. Furthermore, males responded to many female scents by olfactory investigation and/or overmarking, whereas females never showed an observable behavioral response to male scent marks. The marking frequencies of two females did not change significantly during the breeding season, while those of two others decreased significantly. These results suggest qualitative changes of female scents during estrus and a less important role of male scents in intersexual communication in the context of reproduction than previously thought.     

Severe Aggression Among Female Pan troglodytes schweinfurthii at Gombe National Park, Tanzania

Aggression is generally more severe between males than between females because males gain greater payoffs from escalated aggression. Males that successfully defeat rivals may greatly increase their access to fertile females. Because female reproductive success depends on long-term access to resources, competition between females is often sustained but low key because no single interaction leads to a high payoff. Nonetheless, escalated aggression can sometimes immediately improve a female’s reproductive success. Resisting new immigrants can reduce feeding competition, and infanticide of other females’ young can increase a female’s access to resources. East African chimpanzees live in fission-fusion communities in which females occupy overlapping core areas. Growing evidence indicates that reproductive success correlates with core area quality, and that females compete for long-term access to core areas. Here we document 5 new cases of severe female aggression in the context of such competition: 2 attacks by resident females on an immigrant female, a probable intracommunity infanticide, and 2 attacks on a female and her successive newborn infants by females whose core areas overlapped hers. The cases provide further evidence that females are occasionally as aggressive as males. Factors influencing the likelihood and severity of such attacks include rank and size differences and the presence of dependable allies. Counterstrategies to the threat of female aggression include withdrawing from others around the time of parturition and seeking male protection. We also discuss an unusual case of a female taking the newborn infant of another, possibly to protect it from a potentially infanticidal female.     

Reproductive Parameters and Maternal Investment in Mandrills (Mandrillus sphinx)

We report on 14 years of reproductive data for semifree-ranging mandrills (Mandrillus sphinx) in Gabon, and we explore relationships between female rank, age and parity, and reproductive strategies. Most births (61% of 132) occurred during the wet season in Gabon, between January and March. Female rank and parity were unrelated to the timing of parturition. Gestation lengths average 175 days (SE = ±1 day; N = 61) and were similar irrespective of female rank, parity, or sex of offspring. Birth sex ratio did not differ significantly from unity (52% male), and was unrelated to maternal rank or parity. Stillbirths and neonatal mortality tended to be more common among lower-ranking females than among either mid-ranking or dominant females. Median age at first birth is 4.71 years, at a median body mass of 7.6 kg, ca 5 years before females attain their adult body mass (median 12 kg). Age at first reproduction is significantly correlated with dominance rank, with dominant females giving birth on average 1.3 years earlier than lower-ranking females do. Interbirth intervals (IBI) average 405 days (range 184–1159 days, N = 103), and are independent of the sex of the offspring. Infant death within 6 months shortened IBI to 305 days. Increasing age and parity are also associated with short IBI, as is higher rank. Maternal rank and parity appear to influence reproductive success in female mandrills, but there is no apparent differential maternal investment by sex.     

Behavioural dominance and reproductive success in female Japanese monkeys (Macaca fuscata)

Eight years of reproductive data (including 248 births) from a translocated troop of Japanese monkeys (Macaca fuscata) living in a 42-ha enclosure provided three measures of female reproductive success: fecundity, survival of infants to 1 year of age, and age at first parturition. No significant relationship was found between social dominance and these measures. Social dominance was considered with respect to both matrilineal and individual female rank. Additional data on female dominance ranks over four generations of adult females revealed no significant concordance over time. The finding that ranks may not be stable over the lifetime of a female is a significant one because the variation in reproductive success among the females of a group is likely to be further diminished by any instability. For 34 females that were adults for the 8-year period considered, there was no significant correlation between the average rank of a female and either fecundity or survivorship of infants to 1 year of age. These data considered along with the results of other studies of female dominance and reproduction suggest that any effect of female social dominance on reproductive success is probably dependent upon resource availability, with significant benefits accruing to high-ranking individuals only during subsistence periods. It is suggested that dominance competition among female macaques may be a behavioural strategy with a variable payoff.     

Male Dominance Rank,Female Mate Choice and Male Mating and Reproductive Success in Captive Chimpanzees

Mating and consequently reproductive success in male vertebrates are predominantly determined by intermale competition and female mate choice. Their relative importance however, is still poorly understood. We investigated the interrelationship between male dominance rank — a formal indicator of male competitive ability — female mate choice, and male mating success in a multimale-multifemale group of captive chimpanzees. In addition, we examined the relationship between male dominance rank and reproductive success determined by genetic paternity analysis over a 13-yr period in the same captive population. We related the frequencies of sociosexual behaviors to the female anogenital swelling stage and female fertile phase as determined by urinary and fecal progestogen analysis. Rates of behaviors in both sexes increased with increasing intensity of female swelling, but they were not influenced by the timing of the fertile phase. Male mating success was clearly related to male dominance rank, with high-ranking males performing the overwhelming majority of copulations. This was mainly due to both rank-related rates of male soliciting behavior and intermale aggressiveness during the period of well-developed female anogenital swelling. Although females solicited copulations mainly from the high-ranking males and thus expressed a mate choice based on rank, their overall contribution in initiating copulations and thus influencing male mating success was low. The data on paternity from the population, which always contained 4 adult males, revealed that -males sired the majority (65%) of offspring. We conclude, that male dominance rank is an important determinant of male mating and reproductive success in captive (and presumably wild) chimpanzees and that female mate choice is of minor importance in modulating male reproductive outcome.     

Interactions of the Males and Females of Three Sympatric Drosophila virilis-Group Species, D. montana, D. littoralis, and D. lummei, (Diptera: Drosophilidae) in Intra- and Interspecific Courtships in the Wild and in the Laboratory

Four species of the Drosophila virilis group, D. montana, D. littoralis, D. lummei, and D. ezoana, occur sympatrically in several locations in northern Europe. Courtship interactions between the flies of the three first-mentioned species were observed at malt baits in Kemi, northern Finland, to find out how the flies of different species recognize conspecific individuals and how interspecific courtships differ from intraspecific ones in the wild. Intraspecific courtships (including females of different reproductive stages) and interspecific courtships were also videotaped and analyzed in laboratory. In the wild the males courted both conspecific and allospecific females, even though the species varied in how much the males were attracted to females of different species. Interspecific courtships usually broke off when the male touched the female or when the male and/or the female vibrated his/her wings, producing acoustic cues. In the laboratory males courted conspecific females irrespective of the reproductive stage of the female, even though the courtships directed toward immature and fertilized females usually included only orienting and touching (no licking and singing). D. littoralis, and very rarely D. montana and D. lummei, males courted also allospecific females. In the few interspecific courtships between these three species, where the male proceeded to singing, females responded to male singing by vibrating their wings. This ended the courtship. It is suggested that both the chemical cues affecting female attractivity and the acoustic signals of males and females, which are produced by wing vibration, function in maintaining sexual isolation between these three species.     

Effect of the odour of vaginal secretion on non-copulatory behaviour of male hamsters (Mesocricetus auratus)

Male hamsters were exposed to female vaginal secretion (in the absence of the female). When subsequently tested with females, their behaviour was determined by whether the test female matched or did not match the vaginal secretion. Less time was spent with mismatching females and less sniffing and licking was directed towards them. The effect of vaginal odour was present up to 3–4 h after the last contact with the secretion. The number of encounters with the vaginal odour and the spacing between them was important in determining the response to mismatching females. Contact with the vaginal secretion as opposed to its volatile components alone was necessary for the discrimination to occur. Discussion centres around the role of the vomeronasal organ and possible physiological pathways underlying the effect.     

Signaling of Reproductive Status in Captive Female Golden-Headed Lion Tamarins (Leontopithecus chrysomelas)

In species in which paternal care has an important impact on the offspring's fitness, concealment of reproductive status has been proposed as a strategy employed by females to prevent males from practicing desertion and polygamy, which would then lead to monogamous or polyandrous mating systems or both. We investigated whether the female's reproductive status is being concealed in golden-headed lion tamarins, which exhibit extensive paternal care and a mainly monogamous/polyandrous mating system. We used a combination of behavioral observations and endocrine data to determine female reproductive status and to examine changes in sociosexual behaviors over the ovarian cycle and between conceptive and nonconceptive cycles. Females clearly signaled their reproductive status by way of proceptive sexual presenting. Males showed increased frequencies of anogenital sniffing and mounting during the fertile period, indicating that they detected changes in olfactory and behavioral cues emitted by females, and they adjusted their mounting behavior accordingly. Males and females also remained in closer proximity before and during the fertile period, which suggests the existence of mate guarding. We discuss a possible function of behavioral advertisement of reproductive status in shaping the mating system in Leontopithecus chrysomelas.