摘要:

AbstractEjaculates were obtained from eight adult male chimpanzees trained to use an artificial vagina. Spontaneously liquefied fractions were collected at 0–1, 1–2 and 2–4 h after ejaculation. The mean volumes of the spontaneously liquefied fractions did not differ significantly among the three fractions. The total number of sperm, the percentage of motile sperm and the percentage of live sperm decreased significantly (P<0.005) between the 0–1 and 1–2 h fractions. Citrate concentration and alpha‐glucosidase activity (mU/ml) decreased significantly (P<0.005) from 0–1 to 1–2 to 2–4 h fractions. The volume of the liquefied fraction correlated positively (P<0.001) with total protein and with total citrate at 0–1, 1–2 and 2–4 h. The total number of sperm correlated positively total with total alpha‐glucosidase activity at 0–1, 1–2 and 2–4 h. Among the biochemical parameters measured, total protein and total citrate correlated positively at 0–1, 1–

ISSN:0275-2565    

DOI:10.1002/ajp.1350370102

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

年代:1995

数据来源: WILEY

摘要:

AbstractRelatively few papers have focused on interbirth intervals in primates, even though the spacing between births is one of the primary determinants of female reproductive success in long‐lived mammals. We present life history data from a ten‐year field study of Costa Rican capuchins (Cebus capucinus), howlers (Alouatta palliata), and spidei monkeys (Ateles geoffroyi). Analyses of intraspecific variability found no significant differences attributable to individual variation in age, parity, weight, or maternal rank. Loss of an infant significantly shortened the interbirth interval in all three species. There was no correlation between annual rainfall and birth rates, but there was a significant clustering of births in the dry season. Survival analyses demonstrated a significant difference between the median interbirth intervals of the three species. Howlers have the shortest intervals (19.9 months), capuchins exhibit longer intervals (26.36 months), and spider monkeys have the longest intervals (34.72 months;. This comparative pattern does not correspond to relative body weights of the three species, but does correspond to relative brain weights. Comparisons to other primates with similar life history characteristics demonstrate that interbirth intervals are best examined at the level of their three component phases: gestation, lactation, and cycling to re‐conception. © 1995 Wiley‐L

ISSN:0275-2565    

DOI:10.1002/ajp.1350370103

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

年代:1995

数据来源: WILEY

摘要:

AbstractMortality statistics from three captive populations of chimpanzees (Pan troglodytes) were combined to generate standard model life tables for each sex in this species. The model is compared to an estimate of survivorship of a group of wild animals, and is applied to an incomplete data set to illustrate how the model may be used to extend estimates of mortality statistics to missing older ages. © 1995 Wiley‐Liss, I

ISSN:0275-2565    

DOI:10.1002/ajp.1350370104

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

年代:1995

数据来源: WILEY

摘要:

AbstractA field study ofSaguinus nigricollis graellsiin the Cuyabeno Faunal Production Reserve, Ecuadorian Amazonia, established the characteristics of the home range and some reproductive aspects of the species. Field data were collected in two climatic seasons: dry, from December 1989 through March 1990, and rainy, from May through August 1990. Eight groups visited and/or lived in the study area during the dry season and ten during the rainy season. Group sizes ranged from two to nine individuals. Population density was estimated at 22–33 individuals per square km. The central group, which was followed intensively, had a home range which included both flooded and non‐flooded forests.Terra firmeforest was most used by the species. The home range of this group was reduced from 56.2 hectares (ha) in the dry season to 41.7 ha in the rainy season, probably as a result of a differential distribution of food plants between seasons. The presence of dense undergrowth where monkeys could hide to avoid predation and or a high concentration of food plants seem related to the preferential use of certain areas in the home range. The home ranges of neighboring groups overlapped considerably and peaceful temporary large groups were frequently observed. A generalized birth peak occurred in January 1990, dry season. In June 1990, rainy season, 40% of the groups exhibited a second birth peak. This reproductive bimodality ofS. nigricollis graellsiindicates a high productivity of the forests at the Cuyabeno site. © 1995 Wiley‐Lis

ISSN:0275-2565    

DOI:10.1002/ajp.1350370105

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

年代:1995

数据来源: WILEY

摘要:

AbstractA cross‐sectional analysis was made of developmental changes in mother‐offspring grooming in Japanese macaques,Macaca,. fuscata. When offspring were immature, time spent grooming by their mothers decreased with offspring age. Soliciting by offspring increased steadily with age, in contrast to their successful soliciting, which decreased gradually until early adolescence. This is in accord with the hypothesis that grooming is one form of post‐weaning maternal investment, which may entail behavioral conflict between mothers and immature offspring. On the other hand, mothers spent much more time for grooming of their adult female offspring than for their adolescent male and female offspring. It is argued that grooming by mothers may shift from a form of maternal investment in their offspring to a benefit to be exchanged reciprocally with them. © 1995 Wiley‐L

ISSN:0275-2565    

DOI:10.1002/ajp.1350370106

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

年代:1995

数据来源: WILEY

摘要:

AbstractWe analyze how the presence of a skilled juvenile capuchin monkey interacting with a mechanical puzzle requiring sequential actions affected the behavior of group‐mates towards the puzzle. Using this study as an example, we suggest a methodological approach to the evaluation of social enhancement of activity and imitation. We suggest that this design could be useful in determining if social and demographic factors influence the occurrence of these phenomena. © 1995 Wiley‐Liss,

ISSN:0275-2565    

DOI:10.1002/ajp.1350370107

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

年代:1995

数据来源: WILEY

ISSN:0275-2565    

DOI:10.1002/ajp.1350370108

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

年代:1995

数据来源: WILEY

ISSN:0275-2565    

DOI:10.1002/ajp.1350370109

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

年代:1995

数据来源: WILEY

ISSN:0275-2565    

DOI:10.1002/ajp.1350370111

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

年代:1995

数据来源: WILEY

ISSN:0275-2565    

DOI:10.1002/ajp.1350370112

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

年代:1995

数据来源: WILEY