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1.
The facial threats of ten captive golden-bellied mangabeys (Cercocebus galeritus chrysogaster) were categorized by object threatened. Adult males threatened more than did females except when the object was a nonhuman primate in a neighboring cage. Juvenile mangabeys threatened mainly in play within their own enclosures. Keepers and observers did not differ in frequency of being threatened by the mangabeys. Adult female mangabeys seemed more concerned with neighboring cages of nonhuman primates than were the juveniles and the males. Human visitors to the enclosures received by far the most threats of any targets, certainly far more than the observers and keepers. They were treated like interlopers. Keepers were treated like familiar conspecifics, observers like familiar neighbors. The implications of these findings for captive management of primates and for observational methods in behavioral primatology are discussed.  相似文献   

2.
Six adult golden-bellied mangabeys (Cercocebus galeritus chrysogaster) displayed sex differences in aggression, grooming, and vocalization. These sex differences persisted across different current living conditions, time in captivity, rearing conditions, presence of offspring, and active mating conditions. The sex differences are evidently quite robust.  相似文献   

3.
The behaviors of three different adult male–adult female pairs of golden-bellied mangabeys (Cercocebus galeritus chrysogaster) were compared. Correlates of restricted social conditions and of the presence of offspring on adult behavior and direction of aggressive behaviors were noted. A captive pair displayed self-biting and other aberrant behaviors, a lone wild-caught pair showed redirected aggression related to sex, and a pair housed with its offspring showed close social proximity and protection of an infant. The implications of housing and experience for space and visitor exposure are discussed. Observer- vs. visitor-directed displays are seen as important measures of group and visitor effects.  相似文献   

4.
Four adult heterosexual pairs of golden-bellied mangabeys (Cercocebus galeritus chrysogaster) were observed at the Sacramento Zoo. The behaviors of the pairs differed with the histories of the individuals involved, degrees of swelling of the females, presence of offspring in their cages, and the nature of distractions near their enclosures. Young wild-born adults without a nursing-aged infant displayed sexual behavior and observer-directed threats. Experienced wild-born breeders with nursing-aged infants and older juveniles showed intense interest in the sexual behavior of the young pair. These breeders displayed mild aggression, both protective and punitive, toward the juveniles and the infant living with them. Captive and abnormally behaving adults displayed self-biting, bizarre postures, and other stress-related behaviors as well as large amounts of visitor-directed aggression. An experienced breeder male paired with the captive female was unable to achieve copulation. To reduce stress in these and other relatively aggressive primate species, careful attention should be paid to housing location, social history, stage of estrus, and presence of offspring.  相似文献   

5.
Summary In Xenopus laevis, adult males but not females produce courtship songs comprised of rapid trills. Two experiments were conducted to determine whether male-typical singing could be induced in females. At 6 different juvenile stages, male and female frogs were gonadectomized and implanted with testes, grown to sexual maturity, and tested for vocal behavior. All frogs with functional testicular implants sang; females sang as much as males. The frequency spectra of the clicks within trills were fully masculinized in females implanted at PM0, PM1, and PM2. There were deficiencies in song quality in females implanted late in juvenile life. Females receiving testis implants at PM3, PM4, and PM5 did not produce clicks with masculine spectral qualities. In a concurrent experiment, adult males and females were gonadectomized and implanted with testes or silicone tubes containing testosterone proprionate. When tested for vocal behavior 10 to 15 months after implantation, 8/10 androgen-treated males, 3/12 androgen-treated females, 5/5 testes-implanted males, and 2/4 testes-implanted females sang. The females that did sing spent much less time singing than males. The click rates of females were uniformly slower than males and no female produced clicks with a masculine frequency spectrum. Thus, testicular secretions can induce male-typical singing in females until late in juvenile development. However, females exhibit a progressive decline in vocal potential with increasing age, culminating in an almost complete loss of singing ability by adulthood.Abbreviations FFT fast Fourier transform - ICI inter-click interval - PM post-metamorphic - TP testosterone proprionate  相似文献   

6.
Many studies of sex differences in primates have been based on small experimental groups of peers in which only a limited range of social behavior could be expressed. In addition, the first few months of life are often the focus of such studies, with relatively little attention paid to older juveniles. In this study, 11 male and 9 female juvenile patas monkeys, living in a captive social group with all age-sex classes available, were observed between 1 and 4 years of age. A subset of seven patas monkeys was also observed between birth and 1 year of age. Here, we report the development of sex differences in independence, play, grooming, positioning behavior, and aggression over the juvenile period. Juvenile male patas monkeys played more and in longer bouts than females, but wrestling (rough-and-tumble play) was not more common among males. There were few differences in behaviors directed to male and female juveniles by other group members. Distinct differences emerged only in the behaviors of the juveniles themselves, with females being more active participants in social and aggressive interactions than males. In general, sex differences in patas monkeys show a mixture of patterns, some of which are predictive of adult sex differences and some of which appear to be specific to the particular demands of the juvenile period in this species  相似文献   

7.
Cercogylus africanus n. g., n. sp. is described from the lungs of Cercocebus galeritus chrysogaster in Kinshasa, Zaire. It is characterized by the elongate, reduced male bursa, the dorsal ray represented by two widely separated branches, and the subterminal anus in the female.  相似文献   

8.
《Anthrozo?s》2013,26(2):106-110
Abstract

Adult golden-bellied mangabeys (Cercocebus galeritus chrysogaster) housed in three structures directed more frequent aggressive facial displays toward human visitors of their same sex than toward humans of other sex. The human male visitors showed the same patterns as did the mangabeys, with men harassing males. Human females were the only ones that did not display this pattern. Infants and small juveniles did not threaten each other across species. All targets of aggression do not produce the same sex differences in mangabey facial threats.  相似文献   

9.
Mitchell  Suzanne E. 《Hydrobiologia》2001,442(1-3):145-156
Sex induction is environmentally stimulated in Daphnia and involves a cue-dependent response for sex determination. Somatic growth was shown to be similar in males and females during juvenile instars, but divergent due to a reduction in male somatic growth, at about the time that females produce ovaries. At this time, males appeared morphologically adult with respect to secondary sex characteristics. Intersex was rare and is unlikely to be important in natural populations. Intersex could be induced in both sexes, and observed more frequently after longer exposure to high temperature, or in the second generation following a temperature change. This indicates an impact on the ability of mothers to determine the sex of the offspring. It may be possible to use intersex characteristics for manipulative investigation of sex-determination mechanisms in Daphnia. Although sex-determination is initiated before birth, intersex occurrence suggests that development of male characters requires an additional process, probably involving hormone activity, during juvenile development and maturation.  相似文献   

10.
The goal of the research reported here was to look for evidence of modifiability of preference for male song in female cowbirds, Molothrus ater. To this end, we investigated whether social experience affected the breadth and consistency of females’ playback preferences for geographic variants of male song. In three experiments, we varied female cowbirds’ exposure to males. Wild‐caught juvenile females showed a preference for local song in their first year when housed without males in sound‐attenuating chambers, as we had found previously with adult females. But we found that neither adult nor juvenile females showed a preference for local over distant song after they had been housed in large, outdoor aviaries with other females but without male residents. Aviary housing with local males did lead to preferences for local songs. These data represent the first unqualified evidence that adult and juvenile female cowbird preferences for song are modifiable. These data add to the growing body of literature suggesting that receivers, as well as signalers, rely on learning during development of their communication system.  相似文献   

11.
A study of the population structure of olive baboons {Papio anubis (J. P. Fischer)) was conducted near Rumuruti and Nanyuki in the Laikipia District of Kenya during 1969. The overall male: female ratio was 96:100 for all animals captured. The sex ratio of immature baboons favoured males, while adult females outnumbered adult males. Male baboons demonstrated an increased mortality during the juvenile stage primarily due to exploratory behaviour. Female baboons demonstrated an increased mortality incurred during the first pregnancy or birth early in the adult stage. About 50 % of adult females had an infant offspring, while about 75% had a juvenile offspring. Adult female baboons in their native environment produce an offspring every 2.5-3.0 years. No birth peak was discernable and births occurred throughout the year.  相似文献   

12.
Life history data are presented for a population of vervets, Cercopithecusaethiops sabaeus, in Barbados, West Indies. The data were obtained from two habituated troops and from vervets captured during a large-scale trapping program. Individuals of known age from one troop were weighed periodically, and separate growth curves generated for males and females. The mean weight of captured adult females was 3.3 kg; that of adult males, 5.3 kg. The average age at sexual maturity is estimated at 34 months for females and 60 months for males. Vervets give birth throughout the year, but most infants are born between April and July. The average interbirth interval following a surviving infant is 11.8 months. The mortality of juveniles is heaviest between birth and 2 years of age and decreases thereafter. Males emigrate from their natal troops at sexual maturity and one incident of a juvenile female emigrating is reported.  相似文献   

13.
Marco Tschapka 《Biotropica》2005,37(3):409-415
I studied the reproduction of the 9 g nectarivorous bat Glossophaga commissarisi (Phyllostomidae: Glossophaginae) in relation to its food choice in a Costa Rican lowland rain forest over more than 2 yr. Reproduction was bimodal with birth peaks in April/May and October/November. The first birth peak coincided with a period of frugivory, whereas the second occurred during a period of almost exclusive nectarivory. All adult females recaptured in consecutive reproductive periods were reproductively active on both occasions, indicating that individual G. commissarisi females regularly reproduce twice per year at the study site. Throughout the annual cycle the mean testis length of the males correlated best with the proportion of females lactating, suggesting a post partum estrous pattern. Animals became reproductively active at about 1 yr of age. Fecal samples showed that females consumed significantly more insects than males.  相似文献   

14.
The birth of an infant to the highest ranking female in a captive social group of stumptail macaques (Macaca arctoides) is described. Along with certain details of delivery behavior, the responses of group members to the birth are given. The alpha male and two juvenile males were sexually aroused just prior to and during parturition. Adult females paid no special attention to the birth. A subadult nulliparous female and a young adult primiparous female showed interest in the eating of the placenta by the female. The new mother's juvenile son was the monkey closest to her for about two hours after the birth; approaches by other monkeys, especially adult males were avoided. Time of delivery, signs of labor, and the behavior of the mother are also included.  相似文献   

15.
Three main hypotheses can explain the origin of the sexual size dimorphism: (1) the birth-size hypothesis, which states that birth size of males is larger than that of females; (2) the growth-rate hypothesis, which states that males grow faster than females; (3) the growth-length hypothesis, which states that males grow for a longer period of time than females. We examined the factors that may contribute to sexual size dimorphism with growth data of striped skunks Mephitis mephitis Schreber, 1776 held in captivity in Manitoba (Canada), from 7 to 72 days of age. At seven days of age, the mass of male skunks (mean = 79.7 g ± 13.9 SE, n = 37) was significantly larger than that of females (mean = 71.2 g ± 15.0 SE, n = 35) but the head and body length was not statistically different between males (mean = 110.3 mm ± 8.0 SE, n = 37) and females (mean = 95.3 mm ± 7.4 SE, n = 35). There was no difference in growth rate for mass or for length between sexes. We were not able to test for a difference in growth length between sexes. Our results suggest that mass dimorphism occurs early in life.  相似文献   

16.
Development of urinary behavior from birth to adulthood was observed in six groups of beagles including normal males (NM), normal females (NF), males castrated soon after birth (CM), males castrated soon after birth and treated with testosterone (T) for the next 90 days (CMT), females exposed to T in utero (FTU), and females exposed to T in utero and during infancy, i.e., the first 30-40 days postpartum (FTUI). Prenatal treatment with T had masculinizing effects on juvenile urinary behavior in FTU and FTUI. On the other hand normal development of fully adult masculine urinary patterns in males and females necessitated both prenatal and postnatal androgenic stimulation. It was not necessary that T be present at the time the overt behavior developed. For example, adult male behavior appeared in FTUI at the same time as in NM, i.e., 6-10 months, although the supply of exogenous androgen in FTUI had been exhausted within 30-40 days after birth. CMT showed precocious development of all components of the adult male pattern. Development of adult responses was markedly retarded in most CM, and their performance did not equal that of NM at 23 months. They were then injected with TP which promptly evoked completely normal male urinary behavior. It is tentatively concluded that T acting before birth and during the juvenile period "prepares" critical CNS mechanisms so that when general maturation reaches the appropriate point adult male behavior develops. Although the preparatory role of T is essential, the behavior is not dependent on T after it has developed.  相似文献   

17.
Sexually matured rainbow trout, Oncorhynchus mykiss, were experimentally infected with the pathogenic Cryptobia salmositica. Spawning female trout were more susceptible to cryptobiosis than sexually mature males. Most infected females (seven of nine) with eggs died before or shortly after spawning while all (nine) infected males survived the disease. Also, none of the uninfected females died. Males initially increased milt production and sperm concentration; however semen production declined as the disease progressed. Sperm from infected males fertilized more eggs than those from non-infected males. No differences in weight and survival were observed between progeny of infected and uninfected males.  相似文献   

18.
Estrous cycle asynchrony likely functions to elevate individual females' sexual attractiveness during female mate choice. Female chimpanzees show physiological estrus as anogenital swelling. Copulations are concentrated during the period of maximal tumescence, which is called the estrous period. A group of female chimpanzees in Mahale Mountains National Park, Tanzania, was shown to display asynchrony in both maximal tumescence and periovulatory periods. We tested the hypothesis that females establish asynchronous maximal tumescence or periovulatory periods with respect to other females to increase copulation frequency and birth opportunities (Hypothesis 1). We analyzed differences in birth rates between four asynchronous years and five nonasynchronous years. Counter to Hypothesis 1, females in periovulatory periods during asynchronous years showed significantly lower birth rates than those in nonasynchronous years. In addition, periovulatory females copulated more frequently on days on which no other female in a periovulatory period was present. These results suggest that birth rates tend to decrease when females experience nonoverlapping ovulation cycles, although copulation frequency is high. Such a decrease in the birth rate may have resulted from the cost associated with multiple copulations. We tested two other hypotheses: paternity confusion (Hypothesis 2) and sperm competition (Hypothesis 3). Both of these hypotheses were partially supported. The highest‐ranking male most effectively monopolized access to receptive females when relatively few other males and receptive females from the party (or subgroup) were present. The viability of Hypotheses 2 and 3 requires that dominant males are able to hinder a female from mating with other males. Given that the male‐biased operational sex ratio created by female asynchrony is likely to reduce the efficiency of mate guarding by dominant males, an asynchronous female may gain a fitness benefit by increasing the probability of mating with at least one male who produces superior sperm. Am. J. Primatol. 73:180–188, 2011. © 2010 Wiley‐Liss, Inc.  相似文献   

19.
I studied proximal spacing within a group of woolly monkeys (Lagothrix lagotricha) during 7 months at Parque Nacional Tinigua, Colombia. I collected a total of 1188 instantaneous samples on focal individuals, recording the number and age/sex class of individuals that were in contact with, <2 m from, <5 m from the focal animal. The results indicate that proximate spacing reflects social affinities and is related to mother–infant relationship and social grooming. Subadult females and adult males are the sex/age classes with the lowest number of individuals in proximity. There are low proximity between adult females and between adult males and high frequencies of nearness between mother and offspring. Associations between males and females were usually low, but in some cases males showed preferences for a given female. There was a relatively gradual increase in spacing between mothers and their offspring as they became older. Old juvenile males were associated chiefly with other males—mostly subadults—whereas juvenile females maintained some proximity only to their mothers. There are also differences in spacing behavior according to different activity types.  相似文献   

20.
Parasites with heteroxen cycles are important sources of information on the trophic relations of hosts. This is particularly instructive for species whose age‐based or sex‐based differences are hardly detected by behavioural observations. Here, we describe the helminth community of the omnivorous southern lapwing (Vanellus chilensis) and evaluate whether it is affected by the host's sex, age and body size. The species is sexually monomorphic in body length, but males are slightly heavier than females. We analysed 112 individuals collected in Curitiba, Brazil, in March 2010. All hosts were parasitized. The helminth community was composed of 10 species (the digeneans Leucochloridium parcum and Athesmia sp., the cestode Infula macrophallus, the acantocephalans Plagiorhynchus sp., Centrorhynchus sp., Mediorhynchus sp., and an unidentified Gigantorhynchida, and the nematodes Heterakis psophiae, Dispharynx nasuta and an unidentified Capillariidae), seven of which were novel reports for this host species. Prevalence ranged from <1% to 99%. Whereas I. macrophallus was the most prevalent species, D. nasuta showed the highest mean intensity and abundance of infection. The former was found in most hosts as single male–female pairs, suggesting the occurrence of intrasexual competition. The infracommunities of juvenile birds showed a higher parasite species richness than those of adult males and females, suggesting the exploitation of a wider array of prey. However, the three classes harboured seven parasite species. Differences in parasite diversity (lower in juveniles, intermediate in adult males and higher in adult females) reflect the evenness in the distribution of parasite specimens among taxa in each age–sex class and are compatible with differences in their foraging strategy. Finally, we conclude based on the cycles of the heteroxen species that southern lapwings preyed upon molluscs, coleopterans, woodlice and earthworms.  相似文献   

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