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1.
Free-ranging patas monkeys (Erythrocebus patas) from El Guayacán island, Puerto Rico, were surveyed to establish values for the hemogram, serum biochemicals, calcium, and phosphorus. Results were tabulated for males and nonpregnant/nonlactating, pregnant, and lactating females. A summary of blood values from previous studies on captive patas monkeys was also tabulated for comparison.  相似文献   

2.
Generalizations about the rate of behavioral development and mother-infant relations in nonhuman primates are often based largely on observations of a few closely related species of macaques. Patas monkeys (Erythrocebus patas)are sufficiently distant phylogenetically and distinct in their social and ecological adaptations from the well-studied macaque species that observations of their patterns of infant development and mother-infant relations may indicate to what extent macaque patterns are typical of Old World monkey species. Eight patas infants living with their mothers in an established captive group were observed for 960 hr over the first year of life. These infants showed a rapid rate of behavioral development and attainment of independence from mothers. Patas also have one of the fastest rates of sexual maturation of any Old World monkey species. This pattern of rapid social and sexual development can be viewed as a response to a highly seasonal savannah environment in which there is a premium on ability to achieve nutritional, locomotor, and social self-sufficiency as quickly as possible and to reproduce as early and as often as developmental constraints will permit. Patterns of infant development and mother-infant relations may be best understood as an integral part of a species’ overall life history pattern.  相似文献   

3.
An habituated group of wild patas monkeys was observed in Kenya for 550 h in 1984. Observations were made primarily during an interval that, as previous studies at the same site had demonstrated, coincided with the annual mating and conception periods. Earlier field studies of patas at other sites had reported that heterosexual patas groups had only a single resident adult male and that mating was harem-polygynous. At the Kenya site, by contrast, as many as six males were simultaneously resident and mated in the group during the conception period. Males adopted a variety of tactics to gain access to receptive females, ranging from opportunistic mating to attempts at sequestration that resembled consort behavior in other cercopithecoids such as savanna baboons and rhesus macaques. Aggressive competition for access to females took place among the males, although the number of completed copulations per male did not bear a positive relation to agonistic dominance rank. For patas monkeys, harem polygyny is only one available option within an overall mating system that is best described as a form of promiscuous polygyny, especially during periods when conception is most likely.  相似文献   

4.
Eight and a half years of dominance relations within a captive group of patas monkeys were analyzed. It was found that matrilineal kinship significantly influenced individuals' ranks. In contrast, with the exception of certain intramatriline changes, increasing age had no predictable effect on overall rank, at least for females (this was untestable for males). Offspring typically challenged maternal dominance and in eight of twelve dyads, offspring either rose fully over their mothers (three cases, all daughters) or at least achieved dominance ambiguity with them. Additionally, two of the four younger sisters with an opportunity to rise in rank over an older sister did so. The group dominance hierarchy was unstable for 75% of the study due to a combination of agonistically induced and demographically induced rank changes. Concentration of the highest ranks in a single matriline showed a stronger association with group hierarchy stability than did the presence of an adult, nonnatal male. Group hierarchy stability was associated with increased affiliation (sitting close and sitting touching), but otherwise there were no behavioral correlations. Individuals' ranks within the group hierarchy were unrelated to their chances of being wounded or having diarrhea. Adult females' ranks were over twice as stable as the group hierarchy (57.1% stability), but stability/instability was not correlated with any behavioral changes. Available evidence suggests that dominance relations play only a minor role in the organization of patas monkeys' intragroup behavior. Am. J. Primatol. 42:41–51, 1997. © 1997 Wiley-Liss, Inc.  相似文献   

5.
Patas monkeys may be especially vulnerable to local extinction because they live in relatively small, female-philopatric groups at low densities and are strongly polygynous. We assessed a patas monkey population in Kenya's 9,700 km(2) Laikipia District over 25 years, using data collected in 1979-1981 and 1992-2004. The data were based on intensive observations of three study groups, "on the ground" counts, and surveys of Laikipia residents. In 1979-1981, a minimum of 415 patas monkeys lived in 14-15 groups. By 2000, the best estimate suggested 310-445 patas monkeys living in 13-17 groups over a greater surveyed area, suggesting that patas monkeys in Laikipia may have undergone a slight decline in numbers over time. Their distribution, however, was similar over time. The relative stability of this population has likely been the result of beneficial co-existence with large-scale cattle ranching. Outside Laikipia, substantial habitat alteration from rising human populations has coincided with the near disappearance of patas monkeys where they were previously more numerous. The small population in Laikipia, probably the largest remaining in Kenya, may therefore be critical to the continued existence of patas monkeys in that country and may be dependent on maintenance of large-scale ranches. Such land use provides patas monkeys with water and broad expanses of Acacia drepanolobium woodlands, the habitat to which patas are restricted in Laikipia.  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.
Caged patas monkeys were evaluated monthly to determine changes in the color of their hair during infancy, adolescence, pregnancy and lactation. From birth until 3 months of age the facial and anterior crown hairs were short, sparse, and completely black. The body fur was a fine, short, fawn-colored hair mixed with longer black hairs which produced a black-tipped effect. During the second 3 months of life the body fur and anterior crown fur became coarser, longer, and changed to a red-brown color. The facial hairs thickened and became longer, but remained totally black. A thin line of black hairs outlined the brow and temple. The black chin hairs were gradually replaced by white from 7 to 24 months of age, and the upper lip hairs changed from black to white during the second year of life. Color changes related to pregnancy and lactation were confined to the nosepatch, cheek, and browline hair. The nosepatch and cheek hair changed from black or grey to completely white, and the browline faded to the approximate color of the body fur. These changes began approximately at the end of the second trimester of pregnancy, maximized during the third month of lactation, began to darken 1 to 2 months later, and returned completely to the black, nonpregnant colors approximately 1 year postpartum. In one nonlactating female, the darkening was delayed until 500 days postpartum and in one female ovariectomized in the light color phase, the darkening was complete 200 days later. The cause of these changes is believed to be hormonal, resulting from altered endocrine function during maturation and pregnancy, which may alter melanocyte stimulating hormone activity.  相似文献   

8.
The distribution of four affiliative behaviors (proximity within 3 m, allogrooming, contact calling, and co-night-resting) were examined in a group of wild patas monkeys (Erythrocebus patas) during a nonmating, nonbirth season. To a greater or lesser extent, dominance rank and kinship influenced these behaviors of the adult females. Since high-ranking females tended to exhibit some of these behaviors with high frequency, they were considered to be acting as the focus of affiliative behaviors and as the center for group cohesion. Furthermore, related adult females also tended to exhibit some of these behaviors with a high frequency toward one another, so that matrilineal kinship was also seen to be an important factor for group cohesion. In contrast, the harem male tended to exhibit these behaviors at a low frequency and/or had no affiliative partner for any of them. Thus, it appears that the social organization of the patas group is concentric, being composed of high-ranking females in the center, low-ranking females at the periphery, and the harem male at the distant periphery.  相似文献   

9.
Observations of the motor patterns used by patas monkeys during allogrooming indicate that this species uses oral movements much more than previously believed. Compared to rhesus macaques, patas show more mouthpicks and licks, and fewer handpicks. Despite behavioral and anatomical evidence for good precision gripping, patas usually remove debris from a partner's fur orally rather than manually.  相似文献   

10.
Based on long-term, although intermittent, observations (2 years 4 months of 14 years), we present data on birth seasonality, age at first birth, interbirth intervals, mortality rates, age at first emigration, and population change of a wild population of West African patas monkeys (Etythrocebus patas patas) in northern Cameroon. Birth season was from the end of December until the middle of February, corresponding to the mid-dry season. In spite of large body size, the patas females had the earliest age at first birth (36.5 monthsold) and the shortest interbirth intervals (12 months) compared to the closely related wild forest guenons. Age at first emigration of the males was considered to occur between 2.5 and 4.5 years. The group size of the focal group drastically decreased between 1984 and 1987, and steadily increased until 1994, then decreased again in 1997. The neighboring group also showed a similar trend in group size. The population decreases were likely to be caused by drought over 3 years. Annual crude adult mortality rate was 4% during population increase periods (PIP) between 1987 and 1994. It rose to 22% during all the periods (AP), including drought over 3 years. Despite their smaller body size, the rate of the wild forest guenons (Cercopithecus mitis) (4%) was the same and much lower than those of the patas during PIP and AP, respectively. The annual average juvenile mortality rate was 13% during PIP and it also rose to 37% during AP. That of wild forest guenons (C. ascanius) (10–12%) was a little lower and much lower than those of the patas during PIP and AP, respectively. These findings were consistent with Charnov's theoretical model of mammalian life-history evolution in that patas with high adult and juvenile mortality showed early and frequent reproduction in spite of large body size. Charnov also considered high adult mortality as a selective force and high juvenile mortality as a density-dependent consequence of high fecundity. Our results support the former but not the latter research findings.  相似文献   

11.
A previous study of passive joint mobility in patas monkeys (Erythrocebus patas) showed that laboratory-caged animals had significantly greater mobility in most joints than age/sex matched free-ranging monkeys. Passive joint mobility on 27 of the same animals was measured 6 months after the caged animals were released onto a 40-hectare island. The results show that within 6 months of becoming free-ranging, typical passive joint mobility is restored. Thus, although caging directly affects measurements of morphologically-determined features in patas monkeys, confinement itself does not necessarily prevent rehabilitation if the immature monkeys are released into a free-ranging environment.  相似文献   

12.
Reproductive statistics were gathered over a 5½-year period on a colony of Erythrocebus patas. Pregnancies occurred throughout the year under laboratory conditions with a suggestion of a mating peak in the late fall and early winter. Menstrual cycles were monitored and found to average 30.6 days in length. Maximal vaginal cornification occured on day 15 of the cycle suggesting a midcycle ovulation. However, production of timed-mated pregnancies indicated ovulation occurred earlier and that breeding on days 10, 11, and 12 after menstruation was more likely to result in pregnancy. The gestation length was found to average 167.2 days in 142 harem-bred females and 167.5 days in 11 timed-mated pregnancies. Sixty-two percent of all pregnancies resulted in live births; 28% of the conceptions terminated with in-utero death of the fetus. Stillborn infants were delivered in 9% of the pregnancies. Infant mortality during the first 6 months of life was 10.2%. Females raised in the colony conceived their first offspring at approximately 3 years of age and males were able to sire infants at 3 years and 8 months.  相似文献   

13.
The socio-ecological model predicts that the quality, distribution, and patch size of food resources determines the dominance hierarchy of female monkeys based on the type of food competition they experience. Comparative studies of closely related species have evaluated the socio-ecological model and confirmed its validity. For example, female patas monkeys in Laikipia, Kenya, form a nonlinear and unstable dominance hierarchy (i.e., egalitarian), whereas females of sympatric, closely related savannah monkeys form a linear and stable dominance hierarchy (i.e., despotic), in accordance with the model's predictions of the characteristics of food resources. I compared agonistic interactions involving food between patas monkeys (Erythrocebus patas) and sympatric savannah monkeys (Cercopithecus aethiops) in Kala Maloue, Cameroon. I found linear dominance hierarchies not only in savannah monkeys, but also in patas monkeys in Kala Maloue. The rates of agonistic interactions during feeding between patas monkeys were equivalent to those between savannah monkeys in Kala Maloue; further, these rates were significantly higher than those of both Laikipia patas and savannah monkeys. The results imply that patas monkeys in Kala Maloue are not egalitarian, but are despotic, similar to savannah monkeys. Disparity in the dominance hierarchies of patas monkeys between Kala Maloue and Laikipia were attributable to the differences in the characteristics of food resources. Although patas monkeys in Laikipia subsist on small and dispersed food resources within a high-density area, those in Kala Maloue subsisted on food resources that were clumped in intermediate-sized patches within a low-density area. This study shows that the socio-ecological model is applicable not only for interspecific comparisons but also for intraspecific comparisons.  相似文献   

14.
Data from a 2-year field study of patas monkeys (Erythrocebus patas) in Kenya support our earlier suggestion that diurnal births are a species-typical pattern of patas. In this respect patas are very unusual, as all existing information shows that nocturnal births are typical of both captive and freeranging monkeys. Patas do not give birth at night because to do so would render ineffective their night-resting strategy which reduces vulnerability to predation at night. Giving birth during the day, however, does not eliminate the risk of being preyed on; nor are all times of day equally favorable for giving birth. Our field data suggest that a patas female gives birth at those times of day when she is least likely to lose contact with her group or to encounter predators.  相似文献   

15.
The menstrual cycles of a captive group of patas monkeys were followed for 15 months by taking vaginal smears and lavages three times a week. Without an adult male in the group, menstrual cycles still showed the expected qualitative changes previously associated with the onset and with the end of a mating period. The addition of an adult male to the female group, once mating season cycles were evident, did not result in further changes in erythrocytes or sediment levels in vaginal samples or cycle regularity. Menstrual-cycle onsets for related females were significantly more synchronized than onsets for unrelated females. Preliminary observations on adult male patas housed separately from the females indicate that they too undergo seasonal changes in physiology and behavior.  相似文献   

16.
The applicability of the baboon-based protection hypothesis was tested with data from a provisioned, free-ranging group of Erythrocebus patas.The age/sex class of the individual which first approached and fed from one of the food hoppers during early morning feeding sessions was noted for 114 mornings. The presence of an observer, and periodically, rhesus monkeys,near the hopper made these approaches analogous to progressions described for feral baboons. Adult patas of both sexes approached and ate first significantly more frequently than was expected based on their respective proportions in the group, and immature monkeys less often. For adult females,initiating feeding was not correlated with dominance rank, although females in the middle and lower thirds of the hierarchy (n = 6 in each third) initiated feeding more frequently than did the females in the top third. The protection hypothesis accounts for the observed behavioral pattern, while explanations based on competitive exclusion and dominance relationships do not adequately account for the results.  相似文献   

17.
A 17 month field study of unprovisioned patas monkeys (Erythrocebus patas pyrrhonotus) in Laikipia, Kenya, using both ad libitum and scan sampling techniques, revealed that the diet of patas monkeys consists primarily of gum of Acacia drepanolobium, arthropods (both free-living and concentrated in the swollen thorns of A. Drepanolobium), and other animals. This type of diet is normally found only in smaller-bodied primates. Results from vegetational transects suggest that the larger-bodied patas monkey can subsist on such a diet because gum and arthropods are relatively easily found in their habitat, thereby minimizing search time. Patas monkeys also spend more time moving and less time feeding (while not moving) than other Old World primates. The characteristic long limbs of patas may have evolved in response to feeding on small, nonusurpable, and widely distributed foods, in which access to foods is maximized while time and energy spent in terrestrial travel between food sites are minimized. Am. J. Primatol. 45:381–398, 1998. © 1998 Wiley-Liss, Inc.  相似文献   

18.
Unfamiliar males were introduced during the breeding season to a stable heterosexual group of rhesus monkeys to determine how the presence of more dominant resident males affected their mating activity and how their entry was received by resident females. Initially, new males were allowed access to females under controlled conditions both in the presence and absence of resident males, simulating situations which may occur under natural conditions. Results indicated that the sexual activity, including ejaculation rate, of the new males was initially inhibited by the presence of more dominant, resident males, but these inhibiting properties did not carry over to periods when the resident males were absent and were diminished with time. Group females preferentially directed their behavior towards the new males throughout the study. These data suggest that although entry of new males into a stable group is at low rank, their subsequent reproductive success may not be reduced and that the association with resident females may facilitate male rhesus transfer between groups observed during the breeding season.  相似文献   

19.
Normal range of joint mobility in the extremities of the patas monkey, Erythrocebus patas, was established for a free-ranging colony of 64 animals at La Parguera, Puerto Rico (Caribbean Primate Research Center). Eighty-five animals that had been caged (30″ × 30″ cages) for up to 5 years were used for comparison. Passive joint mobility of anesthetized animals was measured with a goniometer. Nine parameters (five on the forelimb and four on the hindlimb) were measured on each animal. The data were sorted into subsets according to the animal's age, sex, place of birth, and type of confinement, if any. The number of animals in each subset was recorded and the mean (in degrees) and standard deviation for each parameter were calculated. A P?0.05 on two-tailed Student's t-tests was considered significant. Comparisons between free-ranging males and females showed significant differences in one or two parameters for all age groups. A cross-sectional sample of free-ranging animals of both sexes showed that significant changes in joint mobility occurred only in the first 18 months of life. Joint mobility of all caged animals, however, was highly variable, and even between the more mature animals there were significant differences in several parameters. Almost all comparisons of subsets of the same age and sex showed significant differences between caged and free-ranging animals in at least one parameter. When the caged animals were laboratory-born, however, these differences were significant in five out of nine parameters. The results suggest that, although caging itself affects joint mobility, the age of first confinement may have an even greater effect than the length of the confinement.  相似文献   

20.
Infanticide by males has been hypothesized to be a naturally selected behavioral strategy that increases the infanticidal male's reproductive success. The sexual selection hypothesis has been challenged via alternative, nonadaptive hypotheses that dispute its empirical and theoretical bases. Two of the most widely recognized alternatives are the social pathology hypothesis, in which infanticide results from overcrowding or recent human disturbance, and the generalized aggression hypothesis, in which infanticide is an epiphenomenon of increased male aggression. We report the first case of infanticide in wild, seasonally breeding patas monkeys (Erythrocebus patas) living at a low population density in a stable habitat, conditions which do not support the social pathology hypothesis. Its exceptional occurrence is consistent with the sexual selection hypothesis: over a 7-year period the infanticidal male was the only one of 13 resident males that was not present during the actual conception season but was present during the following birth season. Also consistent with this hypothesis, mothers were differentially targeted for male aggression, which increased sevenfold during the days surrounding the infanticide and then decreased to baseline levels after the infanticide. Aggression targeted at mothers does not support the generalized aggression hypothesis. As predicted by the sexual selection hypothesis, females began soliciting mating immediately after the infanticide, despite its occurrence in the nonconceptive season.  相似文献   

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