摘要:

AbstractCoordinated travel by social groups is well documented, often with evidence that cognitive spatial maps are employed. Yet the mechanisms by which movement decisions are made and implemented within social groups are poorly known. In a field study of white‐faced capuchin monkeys in Costa Rica it was demonstrated that a specific call, the “trill,” is used by adults in the initiation and directing of troop movement. The trills of subadults were restricted to vocal exchanges with other subadults. Continuous vocal recordings were collected of the vocalizations of the 14 members of the study troop. A cumulative 33.7 h of continuous samples and 1,892 sonagrams were analyzed. In addition to vocalizations clearly associated with alarm, distress, or agonistic contexts, two distinct call types were identified, trills and huhs. Age‐sex classes differed in the rate at which both types of calls were produced in different spatial positions within the troop. Adult females and males produced higher rates of trills when in the leading edge compared to all other spatial positions in a traveling troop. Trills at the edge of a stationary troop represented 36 “successful” and 3 “unsuccessful” start attempts; the troop usually moved in the trajectory predicted by a trilling adult's location on the troop periphery within 10 min of the initiation of trilling. Adults also altered the trajectory of traveling troops by trilling at the side and back of the troop (10 “successful” and 4 “unsuccessful” attempts). Huh vocalizations were most predictably produced when a capuchin is in a dense fruit patch. These results emphasize the role vocalizations serve in the coordination and trajectory of group movement in nonhuman primates, especially those populations that are arboreal or in which visual contact is otherwise impeded. © 1993 Wiley‐Liss, Inc.This article is a US Government work and, as such, is in the public domain in th

ISSN:0275-2565    

DOI:10.1002/ajp.1350300202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThe demography and dynamics of two groups, one living in an evergreen cedar‐oak forest (Tigounatine) and the other, in a deciduous oak forest (Akfadou) in Algeria, were studied from 1982 to 1990. Group size fell within the range of other wild groups except for the Tigounatine group when it reached 88 individuals before splitting into three new independent groups. The structure of the studied groups, except one which was temporarily “one male,” was comparable to that of other groups of Barbary macaques. There were 43–50% of immatures on average depending on the group. The sex ratio (M:F) of the sexually mature animals was relatively balanced (1:0.9–1.2). The mean age of primiparous females was 5.5 years in Tigounatine and 5.3 in Akfadou; the rate of reproduction of sexually mature females was 0.56 and 0.63, respectively, while the infant mortality rate was 0.23 and 0.38, respectively. Great interannual variations occurred at both sites. The differences between natality and mortality induced a higher intrinsic mean annual increase for the Tigounatine group (14.6%) than for the Akfadou group (4.8%). The rate of intergroup transfers was not correlated with the increase in group size. Integration of male immigrants did not lead to the departure of resident males. Conversely, fission process promoted a substantial increase in the number of transfers in Tigounatine.The period presenting the greatest risk of infant mortality was the summer dry period, in both habitats. Wide interannual variations occurred in the availability of two staple foods for monkeys: caterpillars and acorns. The cumulative effects of a low acorn supply during the gestation period (autumn) and a low caterpillar supply during the beginning of the following nursing period (spring) led to a temporary increase in infant mortality. © 1993 Wiley

ISSN:0275-2565    

DOI:10.1002/ajp.1350300203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractVervet monkeys (Cercopithecus aethiops sabaeus) show individual differences in approach‐avoidance behavior when faced with an unfamiliar and potentially threatening situation. Prior research from our colony demonstrated that juveniles who had experienced high levels of early maternal protectiveness were more cautious in response to novelty, compared to juveniles who had had less protective mothers. The research reported here was designed to verify this result in a paradigm that experimentally varied maternal protectiveness through the introduction of new breeding adult males. Mothers responded to the presence of new males by increased maternal protectiveness toward infants born in the year following the introductions. Individual differences in response to the unfamiliar were later evaluated by measuring the latency to approach within 1 m of novel food containers placed into the home enclosure of four naturally composed social groups. Infants approached with the same latency and in the same order as their mothers. Juveniles approached sooner than, and independent of, their mother's current behavior, but their latency to approach could be predicted by the experimentally induced variation in maternal protectiveness they had experienced as infants. Immatures who had been born in New Male years, when maternal protectiveness was high, were more cautious and had significantly longer latencies to approach the novel stimulus compared to immatures who had been born in Resident Male years. © 1993 Wiley‐Liss,

ISSN:0275-2565    

DOI:10.1002/ajp.1350300204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractIn a colony of captive marmoset monkeys (Callithrix jacchus), the survival rate of infants up to the age of 90 days after birth was analyzed with special reference to the number of members in the group. The number of group members (newborns excluded) varied between two (parents only) and 18 (parents plus non‐reproductive helpers); the number of adult group members varied between two and 15. Five hundred ninety‐two live‐born, parent‐reared infants of 263 litters from 56 breeding females were included in the analysis. The greatest reproductive success was observed in groups of ten to 11 members or four to five adults, including the parents. However, the survival rate was fairly constant over group size at approximately 80% of an expected maximum value and no significant correlation was observed between the total number of group members and infant survival rate, or between the number of adult members and infant survival. While helpers may be necessary to increase the survival rate of infants in wild groups, help of non‐reproductive animals is not required in captivity, where energetic demands are comparatively low and ecological constraints absent. Under laboratory conditions the parents' skill in infant handling and the mother's physical condition, i.e., the ability to provide enough milk for the infants, is likely to be the most important factor for infant survival. © 1993 Wiley

ISSN:0275-2565    

DOI:10.1002/ajp.1350300205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractIn an attempt to examine possible associations between stages of agespecific mortality and various causes of death, vital records of 159 male and 192 female crab‐eating monkeys (Macaca fascicularis), housed as a single group, were analyzed. Survival and hazard rates associated with each of five distinct categories of causes of death were estimated for males and females, using the nonparametric kernel method. The obtained overall survival and hazard functions were similar to those reported previously for rhesus monkeys. Among two stages identified in age‐specific mortality, the first stage, characterized by rapidly decreasing hazard rates up to about 1.5–2 years of age, was discriminated by the occurrence of deaths due to unfitness for postnatal life. The second stage lasted up to the age of 10–15 years and was largely characterized by a high incidence of violent deaths. The respective hazard rates in males and females attained peaks during the early reproductive period of life and markedly decreased thereafter. This pattern was interpreted to indicate that second stage mortality is unlikely related to senescence, but rather, seems to depend on extrinsic environmental factors. Thus, when considering overall hazard rates inMacaca fascicularis, the onset of senescence, as a result of the specific aspects of simian reproduction, may be hidden from view, and mortality due to aging may only be appreciable after 10 to 15 years of age. © 1993 Wiley

ISSN:0275-2565    

DOI:10.1002/ajp.1350300206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractWe used morphometric techniques and isotope‐labeled water to investigate the influence of abundant, accessible food and resultant low activity levels on body size and fatness in free‐living adolescent and adult baboons as compared to animals in the same population that experienced more typical, wild‐feeding conditions. Females that had access to abundant food from a nearby garbage dump averaged 16.7 kg body mass, 50% more than their wild‐feeding counterparts in adjacent home ranges. Little of the difference was due to lean mass: the animals with an accessible abundance of food averaged 23.2% body fat in contrast to 1.9% for the wild‐feeding animals. Significant differences between feeding conditions were found for all measured skinfolds and for upper arm circumference but not for linear measurements. Differences between feeding conditions were less for males than for females, perhaps reflecting persistent effects of nutritional conditions during the first eight years of life before dispersal from the group of birth. The difference in fatness between feeding conditions was similar to the difference between humans with frank obesity and those that are considered lean, but in both cases the percentages of body fat in the baboons were considerably less than those observed in humans. In levels of fatness, the relatively sedentary animals resembled their counterparts in group‐housed captive conditions. © 1993 Wil

ISSN:0275-2565    

DOI:10.1002/ajp.1350300207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThe intensity of sperm competition is often measured using the gonadosomatic index (testes/body weight). But sperm competition could be mediated more by size of the epididymis than by size of the testicles, and little information is available on the relationship between testicular and epididymal size. We found that both organs were positively correlated in size among male rhesus macaques. Body weight accounted for over 70% of the variance in testicle size and volumetric estimates of testicle size accurately reflected testicle weight. We conclude that methods for ascertaining testicle size are accurate, but the covariation in size between testicles and epididymis will hamper understanding of the physiological mechanisms involved in sperm competition in primates. © 1993 Wiley‐Liss, I

ISSN:0275-2565    

DOI:10.1002/ajp.1350300208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractMilking under anesthesia in pregnant free‐ranging Japanese macaques (Macaca fuscata) directly revealed lactation in gestation at Jigokudani Monkey Park, the Shiga Heights, Nagano Prefecture, Japan, from 12 to 14 February 1992. Multiparae secreted milk at 76–97 days of estimated fertilization age when the birth intervals to the next offspring were 2 years. The observation of sucking behavior from February 1991 to March 1992 indicated that concurrent suckling by these multiparae terminated approximately 70 days before the next parturition after the growth of fetuses had accelerated and the embryos survived the crisis of abortion. Thus, Japanese macaque mothers appear to hedge maternal investment with concurrent lactation against possible miscarriage. Two nulliparous pregnant females secreted milk 3 months before the first parturition although they had no suckers. The first preparation of lactation appears to require the duration of longer than 3 months in nulliparae although worked mammary glands appear to be able to resume within 1 month in multiparae. © 1993 Wiley‐Lis

ISSN:0275-2565    

DOI:10.1002/ajp.1350300209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

ISSN:0275-2565    

DOI:10.1002/ajp.1350300210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

ISSN:0275-2565    

DOI:10.1002/ajp.1350300201

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY