13 research outputs found
Locomotor anatomy and behaviour in olive baboons : integrative analysis from early infancy to autonomy
Morphom\ue9trie des segments corporels du Gibbon \ue0 favoris roux (Nomascus gabriellae) : \ue9tude de quatre individus vivant en parc zoologique
Bipedality from locomotor autonomy to adulthood in captive olive baboon (**Papio anubis**) : cross-sectional follow-up and first insight into the impact of body mass distribution
Behavioral implications of ontogenetic changes in intrinsic hand and foot proportions in olive baboons (Papio Anubis)
International audienc
The origin of bipedality as the result of a developmental by-product : the case study of the olive baboon (**Papio anubis**)
Development of bipedal walking in olive baboons, **Papio anubis** : a kinematic analysis
Small vertebrates running on uneven terrain: a biomechanical study of two differently specialised lacertid lizards
While running, small animals frequently encounter large terrain variations relative to their body size,
therefore, terrain variations impose important functional demands on small animals. Nonetheless, we
have previously observed in lizards that running specialists can maintain a surprisingly good running
performance on very uneven terrains. The relatively large terrain variations are ofset by their capacity
for leg adjustability that ensures a ‘smooth ride’ of the centre of mass (CoM). The question as to how
the efect of an uneven terrain on running performance and locomotor costs difers between species
exhibiting diverse body build and locomotor specializations remains. We hypothesise that specialized
runners with long hind limbs can cross uneven terrain more efciently than specialized climbers with a
dorso-ventrally fattened body and equally short fore and hind limbs. This study reports 3D kinematics
using high-speed videos (325Hz) to investigate leg adjustability and CoM movements in two lacertid
lizards (Acanthodactylus boskianus, running specialist; Podarcis muralis, climbing specialist). We
investigated these parameters while the animals were running on a level surface and over a custommade uneven terrain. We analysed the CoM dynamics, we evaluated the fuctuations of the positive and
negative mechanical energy, and we estimated the overall cost of transport. Firstly, the results reveal
that the climbers ran at lower speeds on fat level terrain but had the same cost of transport as the
runners. Secondly, contrary to the running specialists, the speed was lower and the energy expenditure
higher in the climbing specialists while running on uneven terrain. While leg movements adjust to the
substrates’ variations and enhance the stability of the CoM in the running specialist, this is not the case
in the climbing specialist. Although their legs are kept more extended, the amplitude of movement does
not change, resulting in an increase of the movement of the CoM and a decrease in locomotor efciency.
These results are discussed in light of the respective (micro-)habitat of these species and suggest that
energy economy can also be an important factor for small vertebrates
Impressive arboreal gap-crossing behaviors in wild bonobos, pan paniscus
Most primates are arboreal, and the current context of habitat fragmentation makes gap- and road-crossing behaviors more and more common. Great apes may try to avoid behaviors such as arboreal leaping because given their size such behaviors are risky. Here, we report impressive gap-crossing by wild bonobos (Pan paniscus) in the Democratic Republic of Congo, induced by human disturbance and habitat fragmentation. We quantify the basic mechanics of leaps and arboreal landing performance in two individuals. The bonobos climbed a tree, 15 m high, and performed pronograde leaps between thin flexible branches, to grasp landing branches ca. 4 m further and below their starting point. They reached an instantaneous velocity of about 9 m center dot s(-1). The bonobos used pendular swinging of landing branches to dissipate the kinetic energy built up during falling, requiring a grip force of about 2.5x body weight. Moreover, our results show that bonobos might be able to modulate the drag experienced during falling (up to 20% of body weight) by adjusting their posture. Apparently, bonobos evaluate the structural context to perform the best possible leap and balance the risks against the extra energetic costs involved. Further study of locomotor performance is needed to inform conservation planning, owing to the extent of habitat fragmentation due to human activities