Kinematics and spatiotemporal parameters of infant‐carrying in olive baboons

Abstract

In the field of biomechanics of quadrupedal locomotion in primates, infant-carrying has received little attention. This study presents the first biomechanical study of infant-carrying in captive female olive baboons (Papio anubis). We test whether females carrying infants conform 1) to the Support Polygon Model (Rollinson and Martin: Symp Zool Soc Lond 48 (1981) 377-427) of gait selection, according to which diagonality should decrease when the infant is carried cranially and increase when the infant is carried dorsally and caudally; 2) to Biewener's (Biewener: Science 245 () 45-48) theory of limb postures, according to which females should extend their hind limbs more due to infant load, especially in the later stages when the infant is not fully autonomous but relatively heavy. This study focuses on the sagittal kinematics of quadrupedal gaits (joint angles and spatiotemporal parameters) of four females with and without infant loads at the CNRS Primatology Station (France). High-speed video recordings were made using the technical platform "Motion Analysis of Primates" available in the animals' place of life. Regarding diagonality, our results do not fully conform to those predicted by the Support Polygon Model of gait selection; however, the model cannot be rejected at this stage in experiment. With regard to limb posture, our results do not support Biewener's (Biewener: Science 245 () 45-48) theory: loaded females do not extend their hind limbs more as predicted; on the contrary, the hind limbs tend to be more flexed when the infant they carry is relatively heavy.

Intrinsic limb morpho‐dynamics and the early development of interlimb coordination of walking in a quadrupedal primate

“…Although this is suggested to be linked to a more caudal position of the BCoM (e.g. Gray, ; Rollinson & Martin, ; Cartmill et al ., ), our results do not allow to conclude on this point (see also Young et al ., ; Anvari et al ., ), despite the fact that the study specimens exhibit a more caudal BCoM position at C2 mainly due to a lighter head, relatively (Druelle et al ., ). Our second hypothesis is therefore not validated and again, this seems to suggest that intrinsic morpho‐dynamics may be less determinative than neuromotor control in the developmental emergence of diagonal sequences in quadrupedal walking (Vilensky & Larson, ).…”

“…The more caudal the position of the BCoM, the higher the proportion of the diagonal sequences should be in the walking gait (i.e. forelimb touchdown follows the contralateral hindlimb; Hildebrand, 1967; but see Young, Patel & Stevens, 2007;Anvari et al, 2014). Taking all these arguments together, interlimb coordination could be seen as the result of interactions between control by the nervous system and the intrinsic morphological and dynamical properties (morpho-dynamics) of the musculo-skeletal systems (NPPs, BCoM, limb CoM).…”

Holding-on: co-evolution between infant carrying and grasping behaviour in strepsirrhines

“…This pattern has only been reported for Simias concolor, Presbytis potenziani, Cebuella pygmaea and Procolobus verus among anthropoids, but is also found in several strepsirrhines1622. In other species, infants are born with grasping extremities enabling them to cling to the mother’s fur efficiently from birth onward13192021. This pattern typifies most apes and monkeys and some strepsirrhines, including all of the Eulemur species1618 and Lorisidae.…”

“…In the majority of primates the young are not left unattended during foraging but instead are carried by their mother1718. Surprisingly, this behaviour has received relatively little attention1920. Some variation between species exists, however, and two main patterns of infant carrying can be distinguished16.…”

Segmental morphometrics of the olive baboon (Papio anubis): a longitudinal study from birth to adulthood

“…The individuals were measured every 3 months until they were 2 years old and then every 6 months. All the individuals studied are part of the same troop and live together in a large park with various enrichments (Anvari et al 2014;Berillon et al 2010;Druelle & Berillon, 2013; see Supporting Information Table S1 for information on the individuals).…”