摘要:

The structural mechanics of femora and humeri from primates representing a wide spectrum of habitual locomotor activities were examined to determine how cross-sectional properties vary with functional specializations of the extremities. Average bending rigidities of the midshaft of humerus and femur were measured in 60 individuals of four nonhuman primate species (Macaca nemestrina, Macacafascicularis, Presbytis cristata, Hylobates lar) using single-beam photon absorptiometry. Linear regression analyses of the loge transformed data were used to assess the relative usage of the forelimb and hindlimb in propulsion and weight bearing, and to evaluate deviations from generalized mammalian quadrupedalism. The results suggest that (1) average bending rigidities of the humerus and femur in primates reflect the extent to which the forelimb and hindlimb are used differently in locomotion; (2) deviations of average bending rigidity from geometric similarity indicate functional variations from generalized mammalian quadrupedalism and (3) the ratio of humeral to femoral bending rigidity can be used to identify trends towards hindlimb or forelimb dominance in locomotion and can be employed in general to determine how the limb was used.

ISSN:0015-5713    

DOI:10.1159/000156218

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Habitat use of two semifree-ranging groups of lemurs, Lemur catta and Lemur fulvus, was studied in relation to abiotic, floristic, and structural characteristics of their enclosure. L. catta was very flexible in the use of the habitat and showed a tendency for random utilization. But this species reacted quickly to changes of the abiotic environment. L. fulvus preferred to stay in areas with dense vegetation but good lateral visibility and close to the food plants. Abiotic factors such as solar radiation and ambient temperature influenced L. fulvus to a lesser extent than L. catta. According to these results L. catta could be considered to be adapted to variable environments where it is advantageous to react quickly to changes of abiotic factors. The conservative habitat use and the limited response to abiotic factors of L. fulvus might reflect adaptations of a species living in a stable environment. If these interpretations prove correct, then this study provides another example of animals born and raised in captivity that have retained habitat preferences of their wild conspecifics.

ISSN:0015-5713    

DOI:10.1159/000156219

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Cranial and mandibular remains of the subfossil lemur Hapalemur (Prohapalemur) gallieni (Standing 1905) from Ampasambazimba in central Madagascar are reexamined and are shown here to belong to the rare but perhaps still extant species Hapalemur simus. Past descriptive errors and too limited comparisons have hampered previous taxonomic assessments of the three mandibular rami, two partial maxillae, and one partial cranium ascribed to H. (Prohapalemur) gallieni. These and other subfossil H. simus recently discovered at the Grotte d’Andrafiabe, Ankarana Massif (in the very northernmost part of Madagascar), and at the Grottes d’Anjohibe, near Mahajanga (northwest coast), show that H. simus was once extensively distributed on Madagascar. Records associated with 9 additional individuals in museum collections show that, at least until about 100 years ago, H. simus occupied much of the humid eastern forests of Madagascar, from the forests east of Fianarantsoa (where it lives today if it has not very recently become extinct) to as far north as ‘Passumbée’ (Ampasimbe) which was located in the region of the Bay of Antongil. This paper reviews what is known of that distribution and the reasons for the taxonomic confusion surrounding the large species of H

ISSN:0015-5713    

DOI:10.1159/000156220

出版商:S. Karger AG    

年代:1985

数据来源: Karger

ISSN:0015-5713    

DOI:10.1159/000156221

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

This study describes the reactions of adult, rearing-experienced members of three Callithrix jacchus families to interactions between animals without rearing experience and infants. The direct involvement of adult group members in situations in which inexperienced animals interact with infants decreases as the infants become older. Inexperienced animals will approach infants more seldom, if adult, rearing-experienced animals are nearby. Adult, rearing-experienced members of the group display primarily noninteractive behavior. This is especially true when no physical contact has taken place between an inexperienced animal and the infant, or if contact was initiated by the infant. Most of the dissociative reactions were observed in the context of competition for objects and play activity. However, there was a similarly high percentage of associative behavior towards inexperienced animals during play activity. In the episodes observed, the adult, rearing-experienced animals displayed mainly taking care behavior towards the infant but never any dissociative behavior. The following points appear to be of significance for the way adult, rearing-experienced members of the group behave: spatial distance between inexperienced animal and infant; which party was the initiator of the interaction; the level of experience already acquired by the animals without previous rearing experience, and the level of maturation of the infant.

ISSN:0015-5713    

DOI:10.1159/000156222

出版商:S. Karger AG    

年代:1985

数据来源: Karger