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V Bels

Publications and source records attributed to V Bels.

4 recordsLinked to original sources
PubMed2006

Substrate optimization in nut cracking by capuchin monkeys (Cebus apella).

We conducted an experiment to examine the effect of substrate on the nut-cracking behavior of a group of semicaptive capuchin monkeys. We wanted to determine whether tufted capuchin monkeys were selective in choosing the substrate on which they pound nuts, and whether the choice of substrate affected the outcome. Eight adult females and eight juveniles were provided with nuts in the outdoor facility. We found that 1) all adult females and three young capuchins succeeded in cracking nuts; 2) they preferred the hardest substrates (concrete and stone); 3) there is a link between the substrate and the amount of time needed to crack a nut; 4) most young capuchins used various substrates, some of which were inadequate, in a haphazard manner; and 5) there are different forms of nut cracking. We conclude that adult capuchins choose the hardest substrates, and that these substrates support efficient cracking.

Animals↗
PubMed2001

Biomechanics and kinematics of limb-based locomotion in lizards: review, synthesis and prospectus.

The sprawling pattern of locomotion in lizards is kinematically intriguing and is underpinned by a distinctive pattern of appendicular morphology. The statics of the sprawling posture dictate fundamental design principles, and these place constraints on the three-dimensional kinematics of the limbs and body axis as locomotion is effected. The fore and hind limbs accommodate these constraints and dictates in fundamentally similar, but positionally different ways, resulting in different kinematic profiles for these two appendages. Recent kinematic investigations have helped to clarify earlier generalizations about lizard locomotion and have revealed that kinematic patterns are more variable than was previously supposed. Such analyses, and attendant detailed studies of the anatomy of the locomotor system, promise a new synthesis and enhanced understanding of evolutionary patterns of locomotion of lizards and adjustment to various locomotor substrata and modes of progression.

Animals↗
PubMed1994

Morphological and kinematic study of the tongue and buccal cavity in the lizard Anguis fragilis (Reptilia:Anguidae).

BACKGROUND: The ability to detect chemical cues is highly developed in Scleroglossa, and particularly in anguid lizards. This ability was predicted because anguids possess a well-developed vomeronasal organ (VNO) (or Jacobson's organ) and rely largely on chemical cues in various behaviours as other active foragers. In this work, we have investigated the possible functional association between tongue flicking and the VNO in the lizard Anguis fragilis. METHODS: The morphology of the tongue and the buccal cavity was investigated by light and scanning electron microscopy. The kinematics of tongue and jaw movements was studied by high speed cinematography. RESULTS: The epithelial cells of the ventral aspect of the tongue tips show microstructures (microridges, microfacets, micropores) which are not present on other areas of the mouth. Beneath the tongue, the floor of the buccal cavity shows two concave-like elevations suggesting a structural analogy with the anterior processes described in snakes. The apex and the internal margin of these processes bear parallel oblique ridges. Taste buds occur anteriorly on the buccal floor and on the palate and are abundant on the internal side and on the edge on the anterior processes. The tongue showed three modes of tongue flicking: simple downward extension, single oscillation, and multiple oscillations. At each tongue flick, the ventral surface of the tips was observed contacting the substratum. Immediately after the tongue retraction, the buccal floor moved slightly upward. The observation of tongue flicking with the mouth open showed that the anterior processes moved upward when the tongue was retracted. CONCLUSIONS: These observations suggest that following: 1) during tongue flicking the ventral surface of the tongue tips invariably makes contact with the substratum; 2) the microstructures of the tongue tips and the ridges of the anterior processes might be helpful for collecting and receiving, respectively, chemicals during tongue flicking; 3) the anterior processes may be apposed on the roof of the mouth next to the ducts of VNOs when the buccal floor is fully elevated; 4) due to their localization, the taste buds could be equally stimulated by the molecules transferred during tongue flicking.

Animals↗