摘要:

AbstractBetween‐group antagonism or territoriality in primates may serve two different but compatible functions: resource defense or mate defense. Females are expected to be involved more strongly in the first, males in the second. The resource defense hypothesis predicts that home range overlap should decrease as defensibility and population density increase, and that females should be involved in hostile between‐group interactions. The mate defense hypothesis predicts that between‐group relations should be hostile and that males should take the primary role in antagonistic encounters. In a comparative study of 12 populations of 6Presbytisspecies in Southeast Asia, we found support for the mate defense hypothesis; only males produce loud calls, between‐group antagonism is entirely a male affair, and neither defensibility nor population density determine spatial exclusivity or the level of antagonism. We discuss the differences between our findings and traditional interpretations of territorial b

ISSN:0275-2565    

DOI:10.1002/ajp.1350260402

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

年代:1992

数据来源: WILEY

摘要:

AbstractThe present study provides the first evaluation of related changes in serum levels of bioactive FSH (Bio FSH) and immunoreactive FSH (iFSH), and concurrent dynamics of LH and FSH bioactivity throughout the menstrual cycle of the rhesus monkey. Mean concentrations of Bio FSH were elevated on days 0 and 1 (n = 7;P<0.05; day 0 = preovulatory LH surge). Data from individual animals revealed that an average (± SEM) of 1.43 ± 0.29 and 2.71 ± 0.61 discrete surges of Bio FSH occurred in each monkey's follicular and luteal phase, respectively. Analysis of the collective data indicated that periods of increased Bio FSH secretory activity spanned days −1 to 1 and 8 to 10 (P<0.025). Increases in serum Bio FSH and iFSH concentrations were not precisely correlated on a daily basis (38.9%), although 72.2% of the peaks of Bio FSH and iFSH surges occurred within a day of one another. Similarly, only 36.1% of the Bio FSH surges were accompanied by elevations in bioactive LH (Bio LH). A significant rise in Bio LH, but not Bio FSH, occurred on day −1 (P<0.01). Concentrations of Bio LH, but not Bio FSH, were elevated in the early luteal phase (P<0.01). The bioactivity/immunoactivity ratios (Bio/I) of LH and FSH were maximal on the day of the preovulatory surge (P<0.01). On day −1, LH Bio/I significantly increased (P<0.05), but no change in FSH Bio/I was detected. The Bio/I of LH, but not FSH, remained elevated in the early luteal phase. In summary: the relative increase in Bio FSH exceeds iFSH during the preovulatory surge. Surges of Bio FSH occur during the follicular and luteal phases which potentially could support follicle selection/maturation. Divergencies between circulating LH and FSH biopotency may reflect a differential regulation of secretion and/or biosynthesis of these hormones. The prolonged early luteal elevation of LH Bio/I is consistent with the idea of a functional role of elevated LH biopotency in the maintenance of the corpu

ISSN:0275-2565    

DOI:10.1002/ajp.1350260403

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

年代:1992

数据来源: WILEY

摘要:

AbstractSampling decisions affect the efficiency and reliability of data collection, and the appropriateness of the data for analyses of group and individual behavior. We evaluate the correspondence between interval sampling of individual behavior at high temporal density (focal interval sampling) with interval sampling of group behavior at lower density (group scan sampling) in two field studies with neotropical primates, capuchins and squirrel monkeys. The two methods provided consistent estimates of population means and variance for activity profiles, foraging activities, and height above ground. The correspondence between mean values with the two methods was greater when group sampling included individual identities than when a nominal scoring scheme was used. A group scan method (without identification of individuals) can be used alone when information is needed within a brief time, such as initial description of activity budgets of a population. Although individual identities take time to learn, data sets in which the individual is the unit of analysis provide several other kinds of analytical possibilities. We recommend use of a mixed sampling regime containing both of these elements (focal and group sampling) as a good way to minimize the time costs of data collection and as a means to evaluate reliability of data collection by a solo observer.

ISSN:0275-2565    

DOI:10.1002/ajp.1350260404

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

年代:1992

数据来源: WILEY

摘要:

AbstractPositional behavior of two platyrrhine monkeys,Alouatta palliataandCebus capucinus, was observed at La Pacifica and Santa Rosa National Park, Costa Rica. Frequency data for locomotion, postures, support diameters, orientation of supports, and use of canopy were recorded on focal males and females.Alouatta palliatais a frequent user of arboreal quadrupedalism (47%) and climbing (37%), with bridging (10%) representing the next most frequent type of locomotion. Intraspecific comparisons show the smaller‐sized females ofAlouattato prefer very small diameter supports, the lower canopy, and to climb more frequently than the larger males—a pattern opposite to that which has been documented to occur with increasing body size across species. A more limited study onCebus capucinusshows this species to be highly quadrupedal (54%) with moderately high locomotor frequencies for climbing (26%) and leaping (1

ISSN:0275-2565    

DOI:10.1002/ajp.1350260405

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

年代:1992

数据来源: WILEY

摘要:

AbstractRelationships between group‐living primates depend strongly on their position in the group dominance hierarchy and on their relationships with other group members. The influence of various behaviours on social relationships of immature rhesus monkeys (Macaca mulatta) was investigated here. Dominance ranks were established and related to the degree of affiliation in a dyad. Older monkeys were mostly dominant to the younger ones, regardless of kinship. Subordinate monkeys left proximity of their dominant members more often than they were left by them both among siblings and non‐siblings, but the effect of dominance rank on the amount of play initiation and grooming in a dyad differed between these two types of dyads. The amount of agonistic help two individuals provided for each other was low among immatures. Nevertheless, pairs of siblings gave help to each other in agonistic conflicts more often than non‐siblings, and such help was more often reciprocated between siblings than between non‐siblings. Help in agonistic conflicts was positively correlated with the amount of time monkeys spent playing, grooming, or in proximity. Adults tended to interfere less in conflicts of frequent sibling play partners or non‐sibling grooming partners. No evidence was found for young monkeys to exchange reciprocally grooming for agonistic help. It is argued that the time monkeys spend interacting with each other in affiliative interactions increases their familiarity and thus promotes close relationships between them. On the whole, young monkeys' relationships, like those between adults, are influenced strongly by their kinship, and position in the dominance

ISSN:0275-2565    

DOI:10.1002/ajp.1350260406

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

年代:1992

数据来源: WILEY

摘要:

AbstractA wild, group‐living 8.5‐year‐old adult baboon was found to have only a single palpable testicle, the only case of cryptorchidism found among more than 200 males that we have examined. This young adult had an unusually small body size for his age, one that was comparable to that of immature males two years younger, and during maturation his body mass was increasingly small for his age. As a young adult, he also had very low testosterone concentrations, which, in combination with his small size, history of impaired growth, and the absence of any obvious scars around the scrotum, suggest that this is a case of spontaneous unilateral cryptorchidism of unknown cause rather than one of monorchidism arising from injury. Despite striking differences in his growth, adult body size, and testosterone levels, the male's cryptorchidism seemed to have relatively little effect on his social and sexual maturation in his natal group. Nonetheless, it may be related to his inability to gain entry into another group after disp

ISSN:0275-2565    

DOI:10.1002/ajp.1350260407

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

年代:1992

数据来源: WILEY

ISSN:0275-2565    

DOI:10.1002/ajp.1350260408

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

年代:1992

数据来源: WILEY

ISSN:0275-2565    

DOI:10.1002/ajp.1350260401

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

年代:1992

数据来源: WILEY