Pa. Garber et Jd. Pruetz, POSITIONAL BEHAVIOR IN MOUSTACHED TAMARIN MONKEYS - EFFECTS OF HABITAT ON LOCOMOTOR VARIABILITY AND LOCOMOTOR STABILITY, Journal of Human Evolution, 28(5), 1995, pp. 411-426
Knowledge of the positional behavior of living primates offers signifi
cant insight into patterns of habitat utilization, foraging strategies
, and locomotor adaptations in fossil primates. Although it is general
ly assumed that locomotor patterns are strongly constrained by anatomy
, few studies have addressed the question of locomotor plasticity and
the degree to which patterns of positional behavior may vary within th
e same species. In this paper, we provide quantitative data on positio
nal behavior and substrate preference in adult moustached tamarins (Sa
guinus mystax) inhabiting two structurally distinct forest types in no
rtheastern Peru. Despite major between-site differences in forest stru
cture, tree density, liana density, and the extent of the continuous c
anopy, overall patterns of positional behavior were virtually identica
l. At the Padre Isla Field site, quadrupedal progression (55.7%), clim
bing (5.7%) and leaping (24.8%) accounted for 86.2% of travel. At the
Rio Blanco site, these locomotor behaviors (quadrupedal progression, 5
1.6%; climbing, 10.8%; and leaping, 30.9%) accounted for 93% of travel
. Patterns of support preference were more variable, however, and appe
ared to reflect site-specific differences in forest architecture. The
results of this study indicate that both anatomy and local habitat pla
y an important role in directing patterns of positional behavior in mo
ustached tamarins. We argue, however, that locomotor anatomy acts to c
onstrain the efficiency of locomotor choices and that even in forests
of different canopy structure and tree density, tamarins negotiate pre
ferred substrates using consistent patterns of positional behavior. Co
mparisons with other taxa indicate that several species of arboreal pr
imates are similarly characterized by limited between-site variability
in positional behavior.