摘要:

Seven squirrel monkeys were reared in visual and tactile isolation and were provided with species-adequate substitute stimulation. Upon introduction to each other, their early interactive development was observed and compared to that of group-raised conspecifics with respect to novelty effects, basic dealings with each other, and onset of interactive skills.

ISSN:0015-5713    

DOI:10.1159/000156206

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Observations and recordings were made of the female songs produced by 4 adult and mated female Kloss’ gibbons (Hylobates klossii) from a site on Siberut Island, the largest island of the Mentawai Island chain in Indonesia. A statistical analysis of song characteristics revealed that individuality occurs throughout the entire song. The implications of these findings, as well as comparisons to similar studies of individuality on other gibbon species, are presente

ISSN:0015-5713    

DOI:10.1159/000156207

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

If the claim that predation risk is the main factor favouring group living in diurnal non-human primates is correct, a reduction in the risk of predation should lead to: (1) a reduction in the size of a primate group and of the parties into which it fissions, (2) a change in the relationship between the size of a party and its composition, and (3) (in South-East Asia) to a change in the relationship between party size and height in the canopy, for small parties. These predictions were tested in a comparison between a population of long-tailed macaques (Macaca fascicularis) in a Sumatran site where a variety of felids occurs, and one on the island of Simeulue, where no cats occur. The first two predictions were strongly supported, whereas the third was weakly supported by the data. The Simeulue monkeys were also different in morphology (blackish coats, reduced sexual dimorphism), lived at high densities in small home ranges, and were territorial. All these differences between the populations could be plausibly ascribed to the difference in predation risk from felids. It is concluded that the presence of felids has a profound influence on the social organization of this arboreal primate species.

ISSN:0015-5713    

DOI:10.1159/000156208

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

The mating patterns of adolescent male chimpanzees (Pan troglodytes) of the Mahale National Park, Tanzania, were studied. Sequential events associated with their copulations were characterized as follows. (1) In encounter, the female tended to approach the male. (2) In precopulation stage, the male often gave courtship displays. (3) In postcopulation stage, the male often groomed the female. (4) In leaving, the female tended to leave first. In every stage, especially during copulation, adolescent males were sensitive to the presence of adult males. The presence of adult males seemed to be enough to prevent adolescent males from copulating with the female. Influences of adult males on copulation of adolescent males are discussed in relation to male-male bonding in chimpanzees.

ISSN:0015-5713    

DOI:10.1159/000156209

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

On 5 July 1983, the adult male chimpanzees of M group killed and ate a male newborn infant in Mahale National Park, Western Tanzania. The infant is believed to have been sired by one of the M group males. Intergroup infanticide might result in improving reproductive success by eliminating a future competitor. In the present episode, however, there is a fair possibility that the males fostered the erroneous idea that the infant had been sired by the males of another group because its mother had disappeared from M group for several months before parturition. After the infanticide, the social relationship between the mother and M group chimpanzees became more stable.

ISSN:0015-5713    

DOI:10.1159/000156210

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Volumes of the ventral pons (VPo) were measured in 82 brains of primates, Scandentia, and Insectivora, and the relative size of the VPo was expressed by size indices. The reference line was through the prosimian average; the mean index of prosimians was set at 1. The taxonomic groups arranged in a sequence of ascending mean VPo indices were: Insectivora (0.04), prosimians (1.00), monkeys (2.55), apes (4.48) and man (9.44). Thus, the VPo of man is more than 9 times larger than that of isoponderous average prosimians, and more than 230 times larger than that of isoponderous ‘basal’ insectivores. The indices may reflect trends and extent of VPo evolution in primate phylog

ISSN:0015-5713    

DOI:10.1159/000156211

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Volumes of medial, interposed, and lateral cerebellar nuclei (MCN, ICN, and LCN) were measured in Insectivora, Scandentia, and Primates, including man. The relative size of the nuclei was expressed in size indices. Insectivora had by far the smallest cerebellar nuclei. The simians, in general, had larger cerebellar nuclei than the prosimians, but there was considerable overlap. From Insectivora to man, the MCN was the least progressive and the LCN the most progressive. The indices are expected to reflect the relative size of the three longitudinal zones of the cerebellum (vermis/MCN, pars intermedius/ICN, hemisphere/ LCN). They, together with those of the ventral pons and cerebellum (part I), are discussed in relation to the predominant locomotor pattern of a species, and with reference to evolutionary trends in primate phylogeny.

ISSN:0015-5713    

DOI:10.1159/000156212

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Following the studies on slow lorises (Nycticebus coucang) and ring-tailed lemurs (Lemur catta), the visual discrimination learning set was tested on diurnal common tree shrews (Tupaia glis) under almost the same experimental conditions. Their performance was significantly lower than that of lorises and lemurs (p < 0.001). An error factor analysis was made in the three species’ performance. Performance showed a strong relationship with the degree of neocortical developmen

ISSN:0015-5713    

DOI:10.1159/000156213

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

In November 1983 an almost unknown subspecies of the genus Lemur was rediscovered in north-west Madagascar: Lemur macaco flavifrons (Gray, 1867). Because of its karyotype, geographical distribution and morphological distinctiveness, L. m. flavifrons should indeed be classified as an L. macaco subspecies.

ISSN:0015-5713    

DOI:10.1159/000156214

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Thermoregulatory characteristics of slender lorises largely resemble those of other slow-moving Lorisidae: Body temperature is slightly below the normal mammalian level and basal metabolic heat production is only about half of the mass-specific standard. During cold exposure only a rather small body core is kept at a high temperature level whereas large parts of the body are allowed to cool. Contrary to the findings in other Lorisidae slender lorises are more tolerant against high environmental temperatures, largely due to the ability of considerably increasing evaporative cooling.

ISSN:0015-5713    

DOI:10.1159/000156215

出版商:S. Karger AG    

年代:1985

数据来源: Karger