摘要:

AbstractThe effect of social context on experimental foraging in squirrel monkeys (Saimiri sciureus) was investigated. The 12 subjects comprised six pairs in which strong social preference and attraction had been demonstrated during observations of a stable group. Individuals were first trained to discriminate spatially separated rich and poor foraging bins containing 75% and 25% of the food items, respectively, with their partners restrained equidistant from the two bins. The monkeys invested an average of 75.5% of their foraging time in the rich bin. Each individual was then tested with its partner restrained in different locations relative to the bins to determine the effect of partner proximity on foraging patterns. Foraging efficiency at the start of a session was enhanced when the partner was restrained adjacent to the rich bin compared to restraint away from this bin. Over an entire foraging session, however, all conditions providing partner accessibility were similar in yielding enhanced foraging efficiency compared to partner absence. Little time was spent in close physical proximity to the partner under any condition. It is suggested that accessibility of the social partner, rather than close physical proximity, has an important influence on the foraging squirrel monkey. © 1995 Wiley‐Liss, I

ISSN:0275-2565    

DOI:10.1002/ajp.1350360302

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

年代:1995

数据来源: WILEY

摘要:

AbstractIn tamarins and marmosets, long‐term stable sociosexual relationships are formed between heterosexual adults, but these “monogamous” relationships are often formed in groups that contain multiple adults of both sexes. The patterning of interactions during pair formation may therefore be shaped by this demographic profile. We evaluated the development of sociosexual relationships in six captive pairs of Wied's black tufted‐ear marmosets (Callithrix kuhli) during the 80 days from the initial day of pairing. Social behavior, sexual behavior and activity profiles were recorded. Social behaviors, including allogrooming, grooming solicitation, and intragroup monitoring calls, increased across the four 20‐day time blocks. Males were more responsible than females for maintaining intrapair proximity during the first 40 days of pairing. Females and males were equally responsible for intrapair proximity maintenance after this time. The highest rates of sexual behavior, including copulation and proceptive open mouth displays, occurred upon pairing and then decreased non‐significantly over time. The results indicate that sexual relationships in callitrichid primates are not dependent on the prior existence of a social relationship between males and females. Higher rates of copulation, greater male responsibility for proximity maintenance, and male initiative in sexual interactions early in pairing are consistent with a male reproductive strategy in which male‐male competition may be common. © 1995 W

ISSN:0275-2565    

DOI:10.1002/ajp.1350360303

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

年代:1995

数据来源: WILEY

摘要:

AbstractSynchrony among reproductive or other states is a widespread phenomenon of significance in evolutionary theory. A model is presented for use in the measurement of the degree of synchrony in any set of behavioral or biological states, such as menstrual cycling, pregnancy, or lactation. At a given time, maximum group synchrony occurs when all members of a group are in a single state, minimum synchrony occurs when equal numbers are in all states, and intermediate values of synchrony occur for other proportional representations of the states. The model yields group synchrony scores ranging from 0 to 100 by standardizing the average of the absolute deviations among frequencies of occurrence in pairs of states. In addition, individual synchrony is characterized by the proportion of others who share an individual's state at a specified set of times. Properties of the model are discussed, simplified calculation procedures are presented, and the method's usefulness for comparative purposes is illustrated. © 1995 Wiley‐Liss, I

ISSN:0275-2565    

DOI:10.1002/ajp.1350360304

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

年代:1995

数据来源: WILEY

摘要:

AbstractThe loud calls of brown howler monkeys were studied during a year at the Santa Genebra Reserve, in southeastern Brazil. The study group emitted roars and barks on a total of 47 occasions, the majority of which (92%) were restricted to intergroup visual encounters. Loud calls were also elicited by the roars of distant groups (6%) and during intragroup agonistic interactions (2%). Intergroup visual encounters (n = 42) occurred predominantly in seldom used quadrats of the study group home range. In these instances, the loud calls were produced chiefly by the adult male alone (69% of cases), while the study group's two adult females joined the male in the remaining cases. Intergroup physical aggression, such as chase and displacement, was observed during 15 encounters (35% of cases). A dawn chorus does not occur in Santa Genebra—the loud calls were heard most frequently in mid‐morning and again during mid‐afternoon—and they were more abundant during the dry season, when the availability of food (new leaves) in the forest was lower. The data presented here provide some support for the hypothesis that roars of howler adult males are used in assessment of opponents, providing an alternative to energetically expensive chases and fights. However, given the relatively high rate of physical aggression observed during intergroup encounters, a result probably related to the high density of howlers and the consequent high frequency of intergroup encounters observed in this forest (0.7/day), ritualized aggression, in the form of loud calling, is apparently often insufficient to settle disputes. © 1995 Wiley

ISSN:0275-2565    

DOI:10.1002/ajp.1350360305

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

年代:1995

数据来源: WILEY

摘要:

AbstractMost nocturnal Malagasy primates, as well as many diurnal species, are highly endangered in their natural habitat. Captive breeding programs have been established for many species, but detailed information on reproduction is only available for three nocturnal taxa: the mouse lemur (Microcebus murinus), the dwarf lemur (Cheirogaleus medius), and the greater dwarf lemur (Cheirogaleus major). In this study, we present data for another nocturnal Malagasy primate, Coquerel's dwarf lemur (Mirza coquereli), which has been propagated since 1982 at the Duke University Primate Center. Unlike all other Malagasy primates bred in captivity,M. coquerelicycles throughout the year, and is clearly less seasonal in its birth distribution than is C.mediusorM. murinus. Estrous intervals ranged between 19 and 30.5 days. Estrus lasted no longer than 1 day. After an average gestation length of 89.2 days, litters of one or two were born. Females cycled for the first time between 8 and 15 months of age, and gave birth for the first time between 12.8 and 33.5 months of age. The earliest mating of a male leading to conception was observed at the age of 17 months. For males and females, an increase in daylength appears to trigger pubertal development. Males had seasonal changes in testicular volume which were not explained by covariation with body weight. Maximum testis size occurred in spring, when breeding activity was highest. The occurrence of year‐round reproduction inM. coquereli, and the absence of seasonal fattening and/or hibernation, along with their specialized winter diet, may be correlated. © 1995 Wiley‐Liss,

ISSN:0275-2565    

DOI:10.1002/ajp.1350360306

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

年代:1995

数据来源: WILEY

摘要:

AbstractA cytogenetic study of a femaleAllocebus trichotiswas conducted using R‐, G‐, and C‐banding. Its karyotype does not differ from those of the other Cheirogaleinae (Microcebus,Cheirogaleus, andMirza). The absence of chromosomal rearrangement in speciation in this group is discussed. © 1995 Wiley‐L

ISSN:0275-2565    

DOI:10.1002/ajp.1350360307

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

年代:1995

数据来源: WILEY

摘要:

AbstractThere are reasons to consider incomplete the description of sleep in many non‐human primate species. Recording animals by highly sensitive videos to obtain detailed descriptions of nighttime behavior and evidence of muscle activity while in a resting posture, seems a promising approach to the non‐invasive study of sleep in non‐human primates. The present work describes the use of ultrasensitive videocameras to record and analyze spontaneous nighttime behaviors in captive non‐human primates. Its main purpose is to emphasize the utility of videorecordings to analyze nighttime behavior. A heterosexual group of nine stumptail macaques (M. arctoides) was studied. It was possible to identify resting postures: immobility or lying on the floor as well as sleep movements and behavioral signs of sleep. This procedure permits recognition of each animal individually and the data suggest that videorecordings, among other techniques available, may be a useful, non‐invasive method to study sleep. © 1995 Wiley

ISSN:0275-2565    

DOI:10.1002/ajp.1350360308

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.1350360309

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.1350360310

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.1350360301

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

年代:1995

数据来源: WILEY