摘要:

AbstractReproductive parameters and sexual behavior of free‐ranging Hanuman langurs (Presbytis entellus) were studied over a 13‐year period at Jodhpur, India in a population that breeds throughout the year. Long‐term monitoring of individually identified females living in one‐male‐multi‐female troops revealed a mean cycle length of 24.1 days (n = 113), a mean gestation of 200.3 days (n = 31), menarche at 29.0 months (n = 10), first conception at 35.0 months (n = 12), and a mean birth interval of 16.7 months (n = 114). The loss of unweaned infants accelerated the resumption of menstruation, receptivity, and attractivity; shortened the period between estrus and next conception; and reduced the median birth interval by 20.5%, thus supporting the sexual selection hypothesis of male infanticide. The decline of fertility with age (as measured by the rates of conception per estrus period), a regular postreproductive survival for up to 9 years (which can account for about 25% of a female's life span) and indications for the existence of a “true menopause” support the view that a postreproductive period in langurs is the result of natural selection. There is very limited evidence for situation‐dependent receptivity, because only 7.5% of all estrous days (n = 1,037) fell outside of the mid‐cycle period with at the same time strongly reduced proceptivity and attractivity. Moreover, postconception estrus behavior showed a stereotypical pattern during 31 pregnancies and did not reflect a situation‐dependent response to the immigration of new and potentially infanticidal males. It is likely that females competed for sperm of the harem holder, because the probability of conception increased significantly with an increase in the number of copulations, and when the number of females copulating on the same day decreased.

ISSN:0275-2565    

DOI:10.1002/ajp.1350280102

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

年代:1992

数据来源: WILEY

摘要:

AbstractSympatric populations of lowland gorillas (Gorilla gorilla gorilla) and chimpanzees (Pan troglodytes troglodytes) in the Lopé Reserve in central Gabon consumed insects at similar average frequencies over a 7‐year period (30% versus 31% feces contained insect remains). Data came mostly from fecal analysis supplemented by observation and trail evidence. The weaver ant (Oecophylla longinoda) was the species eaten most frequently by both gorillas and chimpanzees. Other species of insects wore eaten but there was virtually no overlap: Chimpanzees used tools to eatApisbees (and their honey) and two large species of ants; gorillas ate three species of small ants. Thus, despite their shared habitat, the esources utilized were not identical as gorillas do not show the tool‐use “technology” of chimpanzees. The frequency of insect‐eating by both species of ape varied seasonally and between years but in different ways. This variation did not seem to be related to the ratio of fruit to foliage in their diets. Gorillas of all age‐classes ate insects at similar rates. Comparisons with insectivory by other populations of gorillas indicate differences exist. Mountain gorillas (Gorilla g. beringei) in the Virunga Volcanoes, Rwanda, consume thousands of invertebrates daily, eating them inadvertently with handfuls of herbaceous foods but they deliberately ingest insect‐foods only rarely. Lowland gorillas at Lopé habitually ate social insects, and their selective processing of herbaceous foods probably minimizes inadvertent consumption of other invertebrates. Gorillas at Belinga in northeastern Gabon, 250 km from Lop6, ate social insects at similar rates but ignored weaver ants in favor ofCubitermes sulcifrons, a small species of termite that occurs at Lopé but was not eaten by gorillas. This indicates that local traditions similar to those reported for chimpanzees also exist amongst populations of gorillas. © 199

ISSN:0275-2565    

DOI:10.1002/ajp.1350280103

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

年代:1992

数据来源: WILEY

摘要:

AbstractWe documented normal pregnancy and the rate of pregnancy failure in female baboons by measuring chorionic gonadotropin (bCG) and progesterone (P) levels in 162 mated cycles of 70 baboon females on days 10, 12, and 14 postovulation. Females were mated with males during turgescene. The presence of pregnancy was defined by bCG levels>20 μg/ml by day 14 postovulation and/or documentation of a gestational sac using ultrasonography. Of the 162 cycles, 75 were fertile. Of these animals, 33 were used in other studies and thus were not included in these analyses. The analyses are based on 43 pregnancies from 91 cycles that were untreated throughout their gestations. Twenty‐six of these pregnancies had abnormal bCG and/or progesterone levels in early pregnancy. All of those pregnancies with abnormal endocrine parameters terminated with spontaneous abortion (60%). Certain abnormal bCG patterns were repeatedly observed in some animals and were correlated with repeated spontaneous abortions. Of 17 pregnancies with normal bCG and P patterns, 15 (88%) continued to term with a normal fetal outcome. In this study, a pregnancy rate per mated cycle of 47% was observed, yet 60% of untreated pregnancies abortyed spontaneously. Overall 16% of the mated cycles had continuing pregnancies with normal outcome. These studies demonstrate that a high rate of early abortions occurs in the baboon and that a single bCG determination is insufficient to define the presence of a “normal” pregnancy which might be expected to carry to term with a normal o

ISSN:0275-2565    

DOI:10.1002/ajp.1350280104

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

年代:1992

数据来源: WILEY

摘要:

AbstractWe describe an approach to analysis of growth that does not depend on assumptions about the underlying functional growth pattern and that allows for multiple observations arising from individual‐specific, irregularly spaced data. We produce estimated growth curves for predefined subject groups by using LOWESS, a nonparametric smoothing algorithm. We describe how statistical significance of curve features may be evaluated by using the “jackknife,” a sample re‐use method; this technique can be used to assess differences between subject groups. We then obtain residuals at each data point by reference to the estimated curve. Consistency of residuals is evaluated as a characteristic of individual subjects, and in the presence of individual consistency, relative size‐for‐age is then scored by the average residual for each individual. This allows study of relationships between relative size and other individual characteristics such as birth order, dominance rank, or age of maturation. Finally, we indicate flexibility of these methods and alternatives, propose uses related to other questions about growth, and suggest potential applications to variables other than body size. Appendices demonstrate application of the LOWESS and jackknife algorithms to the problem of testing sex differences in growth. © 1992 Wil

ISSN:0275-2565    

DOI:10.1002/ajp.1350280105

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

年代:1992

数据来源: WILEY

摘要:

AbstractA one‐male unit (OMU) of chacma baboons (Papio ursinus) in northern Botswana formed by the asymmetrical fissioning of a multimale (MM) group. During long‐term (13 years) observations in this area, which has a relatively high density of baboons, we observed only MM groups with 6 or more adult males per group (N = 19). The behavioral repertoire of the OMU generated a pattern of sociality unrepresentative of these MM groups. Distinctive behavior patterns expressed by the male of the OMU included vigilance oriented away from the group and suppression of intra‐group aggression among all other group members. There was also a difference between the foraging and movement patterns of the OMU and those of MM groups in environmentally similar or the same areas. The OMU moved and foraged in a cohesive formation and all group members often foraged in single fruiting trees. Under comparable circumstances at the same time and places MM groups foraged in dispersed formation. Diet and habitat choices of the OMU differed from those of neighboring groups. Patterns of sociality associated with OMUs have been interpreted as responses to extreme environmental conditions [Byrne et al.: Am J Primatol 20:313–329, 1990]. However, it is also possible that alternative behavior patterns are facultative tactical responses to social circumstances, The alternative social styles of OMUs arising within typically MM populations identify the breadth of the behavioral repertoire and the capacity for social flexibility within contemporary savanna baboon and perhaps other primate populations. © 1992 Wiley

ISSN:0275-2565    

DOI:10.1002/ajp.1350280106

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

年代:1992

数据来源: WILEY

摘要:

AbstractVideolaparoscopy was used to visualize the reproductive tract contractility of the squirrel monkey,Saimiri sciureus. This technique gives information on the nature, direction of propagation, duration, and frequency of contractions. At the times of ovulation, and embryo entry to the uterus, contractile activity was observed in both the uterus and oviduct, with the latter being more frequent. The dominant direction of propagation was towards the utero‐tubal junction, and simultaneous contractions were frequently observed in both uterus and oviduct. © 1992 Wiley‐Liss,

ISSN:0275-2565    

DOI:10.1002/ajp.1350280107

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.1350280108

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.1350280101

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

年代:1992

数据来源: WILEY