Differences in terrestrial velocity in Macaca and Presbytis

Over 150 sequences of terrestrial movement were timed and measured in the toque macaque, the gray langur, and the purple-faced langur to determine the relation between velocity, gait, and psychosocial context. Species differences were found in mean velocity, “favored” gait, and surface preference. All three species used the walk and the gallop at the slowest and fastest speeds respectively. The macaques and gray langurs walked frequently, but the purple-faced langurs were never seen to do so. At intermediate speeds, the macaques used either the “fast” walk or the “slow” gallop, whereas the gray langurs used irregular patterns of walk-gallop-walk-gallop. The purple-faced langurs were faster (about 20 fps) and less variable than the other species, regardless of distance. These data suggest that motor expression varies among the Cercopithecoid monkeys: the correlation between locomotion and anatomy is not as close as it is among wholly terrestrial or arboreal forms; slowness in the macaque is an expression of social confidence, not of biomechanical inability; high speed in the purple-faced langur is due to psychosocial factors rather than to “terrestrial” adaptability.     

Social Behavior of Captive Indochinese and Insular Long-Tailed Macaques (Macaca fascicularis) Following Transfer to a New Facility

There are measurable differences in behavior, physiology, social organization, and geographic distribution within and between various species of macaques. We collected information on the social behavior of captive Macaca fascicularis from Indochina and island populations after they had been transferred to a new environment and new social groups. While some changes in behavior occurred over time, we found no decrease in high levels of agonistic behaviors. We interpret this finding in light of previous research reporting that long-tailed macaques show low levels of habitatuation to novelty and are highly aroused in comparison to other macaque species. We found predictable differences in behavior for males, females, and infants, in which infants played more, females had higher levels of contact proximity to other individuals, and males exhibited more sexual and threat behavior. A comparison of social behavior in long-tailed macaques from different origins indicate that Indochinese macaques are generally less affiliative and Indochinese males are more aggressive than their insular counterparts. Differences among macaque species, and within the fascicularis-group, should be considered in management of captive colonies and when interpreting research data.     

The Influence of Age,Sex, and Rank on Yawning Behavior in Two Species of Macaques (Macaca fascicularis and M. fuscata)

Yawning behavior was studied in two species of macaques: the long-tailed macaque (Macaca fascicularis) and the Japanese macaque (M. fuscata). Japanese macaques yawned much more than long-tailed macaques. Age, sex, and dominance rank exerted different effects on yawning in the two species. In the long-tailed macaques, sex differences in frequency of yawning emerged only after sexual maturity; yawning rates increased significantly in both males and females as they reached sexual maturity; and, among males, dominance rank was positively correlated with frequency of yawning. Differently, in the Japanese macaques, males, both mature and immature, yawned more than same-aged females; sexual maturity was associated with an increase in yawning in males only; and male rank did not correlate with the frequency of yawning. Regardless of interspecific differences, the overall results supported only in part the finding that, in Old World monkeys, yawning is largely influenced by plasma concentrations of androgens. There was evidence that social factors were also important in influencing the age-sex class distribution of yawning.     

四足型灵长类踝关节的生物力学研究

对猕猴属５种踝关节和跟骨生物力学和多变量分析的结构表明,踝关节的运动主要与距骨关节面的形态有关。楔形指数和跟骨指数是区别种间差异的重要指标。结合生态学观察的结果推测,短尾猴和藏酋猴的运动方式最为接近,表现出适应地栖四足型运动的特征,而豚尾猴和熊猴有关对的树栖运动方式,猕猴的运动介于两者之间,既有一定的地栖性运动,也有较大的树栖性运动。     

Positional behavior of long-tailed macaques (Macaca fascicularis) in northern Sumatra

Although the majority of extant primates are described as "quadrupedal," there is little information available from natural habitats on the locomotor and postural behavior of arboreal primate quadrupeds that are not specialized for leaping. To clarify varieties of quadrupedal movement, a quantitative field study of the positional behavior of a highly arboreal cercopithecine, Macaca fascicularis, was conducted in northern Sumatra. At least 70% of locomotion in travel, foraging, and feeding was movement along continuous substrates by quadrupedalism and vertical climbing. Another 14-25% of locomotion was across substrates by pronograde clambering and vertical clambering. The highest frequency of clambering occurred in foraging for insects, and on the average smaller substrates were used in clambering than during quadrupedal movement. All postural behavior during foraging and feeding was above-substrate, largely sitting. Locomotion across substrates requires grasping branches of diverse orientations, sometimes displaced away from the animal's body. The relatively low frequency of across-substrate locomotion appears consistent with published analyses of cercopithecoid postcranial morphology, indicating specialization for stability of limb joints and use of limbs in parasagittal movements, but confirmation of this association awaits interspecific comparisons that make the distinction between along- and across-substrate forms of locomotion. It is suggested that pronograde clambering as defined in this study was likely a positional mode of considerable importance in the repertoire of Proconsul africanus and is a plausible early stage in the evolution of later hominoid morphology and locomotor behavior.     

Climbing,brachiation, and terrestrial quadrupedalism: Historical precursors of hominid bipedalism

The vertical-climbing account of the evolution of locomotor behavior and morphology in hominid ancestry is reexamined in light of recent behavioral, anatomical, and paleontological findings and a more firmly established phylogeny for the living apes. The behavioral record shows that African apes, when arboreal, are good vertical climbers, and that locomotion during traveling best separates the living apes into brachiators (gibbons), scrambling/climbing/brachiators (orangutans), and terrestrial quadrupeds (gorillas and chimpanzees). The paleontological record documents frequent climbing as an ancestral catarrhine ability, while a reassessment of the morphology of the torso and forelimb in living apes and Atelini suggests that their shared unique morphological pattern is best explained by brachiation and forelimb suspensory positional behavior. Further, evidence from the hand and foot points to a terrestrial quadrupedal phase in hominoid evolution prior to the adoption of bipedalism. The evolution of positional behavior from early hominoids to hominids appears to have begun with an arboreal quadrupedal-climbing phase and proceeded though an orthograde, brachiating, forelimb-suspensory phase, which was in turn followed by arboreal and terrestrial quadrupedal phases prior to the advent of hominid bipedality. The thesis that protohominids climbed down from the trees to become terrestrial bipeds needs to be reexamined in light of a potentially long history of terrestriality in the ancestral protohominid. © 1996 Wiley-Liss, Inc.     

Locomotor adaptations reflected in the wrist joints of early tertiary primates (adapiformes)

The positional behaviors inferred for early Tertiary adapiform primates have been the subject of considerable debate. Adapiform wrist morphology is analyzed here within the context of extant morphoclines in carpal joint shape in order to reconstruct adapiform positional behavior. Extant vertical clingers, slow climbers, and arboreal quadrupeds differ significantly from one another in length of the m. flexor carpi ulnaris lever arm, shape of the midcarpal joint articular surface, and size and divergence of the pollical carpometacarpal articulation. These morphological differences are functionally related to differential requirements for wrist flexion, midcarpal mobility and stability, and pollical grasping, respectively. Adapis, Notharctus, and Smilodectes share with living arboreal quadrupeds a tall pisiform body, a mediolaterally flat midcarpal joint surface, and a relatively unexpanded thumb joint. Functionally, these features are related to flexing the wrist from extended positions during palmigrade, quadrupedal locomotion, increasing midcarpal joint stability during quadrupedal, weight-bearing postures, and grasping arboreal supports of predominantly horizontal and oblique orientation. The Messel adapiform (genus indet.) shares certain features of the midcarpal and pollical carpometacarpal articulations with extant vertical clingers, suggesting that this taxon used vertical substrates more frequently than other adapiforms. © 1996 Wiley-Liss, Inc.     

Arboreal locomotor and postural behaviour of European red squirrels (<Emphasis Type="Italic">Sciurus vulgaris</Emphasis> L.) in northern Greece

The study of the locomotion and postures of arboreal squirrels may provide important contextual information on the evolution of the morphology and ecology of sciurids. In this context, we studied the positional behaviour and habitat use of four adult European red squirrels (Sciurus vulgaris L.) in a mixed coniferous forest in northern Greece. Our results show that, during the study period, S. vulgaris extensively used the forest canopy and the terminal branch zone. The use of small and medium supports of all orientations was also particularly frequent. The positional profile of the species was characterized by the dominance of quadrupedal, clawed and airborne locomotion along with seated and standing postures. Quadrupedalism and sitting appeared to promote terminal branch use for food access and manipulation, while claw climbing favored vertical ranging and retreat to trees after terrestrial foraging. Finally, leaping reduced energetic costs during travelling between food sites within the relatively dispersed forest. These results and those of previous research on the positional behaviour of other squirrels reveal several trends related to body size, arboreal or gliding habits and tropical or temperate forest distribution and contribute to the understanding of evolutionary novelty in multiple levels within the sciurid radiation.     

Morphological and Body Color Variation in Thai <Emphasis Type="Italic">Macaca fascicularis fascicularis</Emphasis> North and South of the Isthmus of Kra

Long-tailed macaques (Macaca fascicularis fascicularis) are widely distributed in Southeast Asia and are morphologically and genetically (Tosi et al. in International Journal of Primatology 23:161–178, 2002) distinguishable on either side of the Isthmus of Kra (ca. 10.5°N). We compared the somatometry and body color of 15 local populations of long-tailed macaques in Thailand distributed over areas from 6.5°N to 16.3°N and also a Thai rhesus macaque population at 17.2°N. Limb proportions and body color variation follow the geographical trend. However, contrary to a previous report, body size does not decrease with latitude in the northern group and also in the southern (southerly distributed) rhesus macaque. Relative tail length (RTL) and color contrast in yellow between the back and thigh are the sole traits that distinctively separate the 2 groups: the southern group has a long relative tail length (RTL >125%) and small color contrast, whereas the northern group has a short RTL (<120%) and large color contrast. The southern rhesus macaques appear to have somatometric and body color traits that follow the geographical trend in long-tailed macaques, though they maintain their distinctive species-specific traits of shorter RTL (ca. 55%), shorter relative facial length, and a bipartite body color pattern. Researchers assume that the northern group of long-tailed macaques and the southern rhesus macaques had undergone partial introgression with each other. Montane refugia present during the glacial period are localities in which introgression occurred in long-tailed macaques.     

Subchondral Bone Apparent Density and Locomotor Behavior in Extant Primates and Subfossil Lemurs <Emphasis Type="Italic">Hadropithecus</Emphasis> and <Emphasis Type="Italic">Pachylemur</Emphasis>

We analyze patterns of subchondral bone apparent density in the distal femur of extant primates to reconstruct differences in knee posture, discriminate among extant species with different locomotor preferences, and investigate the knee postures used by subfossil lemur species Hadropithecus stenognathus and Pachylemur insignis. We obtained computed tomographic scans for 164 femora belonging to 39 primate species. We grouped species by locomotor preference into knuckle-walking, arboreal quadruped, terrestrial quadruped, quadrupedal leaper, suspensory and vertical clinging, and leaping categories. We reconstructed knee posture using an experimentally validated procedure of determining the anterior extent of the region of maximal subchondral bone apparent density on a median slice through the medial femoral condyle. We compared subchondral apparent density magnitudes between subfossil and extant specimens to ensure that fossils did not display substantial mineralization or degradation. Subfossil and extant specimens were found to have similar magnitudes of subchondral apparent density, thereby permitting comparisons of the density patterns. We observed significant differences in the position of maximum subchondral apparent density between leaping and nonleaping extant primates, with leaping primates appearing to use much more flexed knee postures than nonleaping species. The anterior placement of the regions of maximum subchondral bone apparent density in the subfossil specimens of Hadropithecus and Pachylemur suggests that both species differed from leaping primates and included in their broad range of knee postures rather extended postures. For Hadropithecus, this result is consistent with other evidence for terrestrial locomotion. Pachylemur, reconstructed on the basis of other evidence as a committed arboreal quadruped, likely employed extended knee postures in other activities such as hindlimb suspension, in addition to occasional terrestrial locomotion.     

Positional behavior of Siberian chipmunks (Tamias sibiricus) in captivity

Arboreal and semi-arboreal mammals have remarkably diverse positional behavior and associated morpho-functional adaptations related to the three-dimensional nature of their arboreal habitat. In this context, we investigated the positional behavior of captive Siberian chipmunks (Tamias sibiricus), small bodied semi-arboreal sciurids, in an aviary-type wire-mesh cage containing both terrestrial and arboreal supports. We sampled four adult individuals during a five-month period using focal animal sampling every 30 s. Results showed that animals preferred 8–10 cm horizontal supports and always avoided vertical supports. Locomotion occurred on both terrestrial and 8–10 cm arboreal supports whereas postural behavior occurred primarily on 8–10 cm arboreal supports. Quadrupedal walk dominated during locomotion, and occurred primarily on terrestrial horizontal supports, as is observed for other squirrels. The predominance of quadrupedal locomotion is consistent with the postcranial morphology of chipmunks. In contrast, clawed locomotion occurred on wire mesh and on >13 cm arboreal vertical supports. Finally, pronograde and orthograde sitting, both on 8–10 cm arboreal supports and on terrestrial supports, were the predominant postures, implying general predisposition to selection of stable postures on stable supports for food item manipulation and ingestion.     

Mediolateral reaction forces and forelimb anatomy in quadrupedal primates: implications for interpreting locomotor behavior in fossil primates

The forelimb joints of terrestrial primate quadrupeds appear better able to resist mediolateral (ML) shear forces than those of arboreal quadrupedal monkeys. These differences in forelimb morphology have been used extensively to infer locomotor behavior in extinct primate quadrupeds. However, the nature of ML substrate reaction forces (SRF) during arboreal and terrestrial quadrupedalism in primates is not known. This study documents ML-SRF magnitude and orientation and forelimb joint angles in six quadrupedal anthropoid species walking across a force platform attached to terrestrial (wooden runway) and arboreal supports (raised horizontal poles). On the ground all subjects applied a lateral force in more than 50% of the steps collected. On horizontal poles, in contrast, all subjects applied a medially directed force to the substrate in more than 75% of the steps collected. In addition, all subjects on arboreal supports combined a lower magnitude peak ML-SRF with a change in the timing of the ML-SRF peak force. As a result, during quadrupedalism on the poles the overall SRF resultant was relatively lower than it was on the runway. Most subjects in this study adduct their humerus while on the poles. The kinetic and kinematic variables combine to minimize the tendency to collapse or translate forelimbs joints in an ML plane in primarily arboreal quadrupedal primates compared to primarily terrestrial quadrupedal ones. These data allow for a more complete understanding of the anatomy of the forelimb in terrestrial vs. arboreal quadrupedal primates. A better understanding of the mechanical basis of morphological differences allows greater confidence in inferences concerning the locomotion of extinct primate quadrupeds.     

Muscle dimensions in the Japanese macaque hand

Macaques have been used as an important paradigm for understanding the neural control mechanisms of human precision grip capabilities. Therefore, we dissected the forearms and hands of two male Japanese macaques to systematically record the muscle mass, fascicle length and physiological cross-sectional area (PCSA). Comparisons of the mass fractions and PCSA fractions of the hand musculature among the Japanese macaque, chimpanzee, and human demonstrated that the sizes of the thenar and hypothenar eminence muscle groups are more balanced in the macaque and chimpanzee, but those of the thenar eminence group are much larger in the human, indicating that the capacity to generate force at the tip of the thumb is more restricted in macaques, despite their high manual dexterity. In the macaque, however, the extrinsic flexor muscles are much larger, possibly to facilitate weight bearing by the forelimbs in pronograde quadrupedal locomotion and forceful grasping of arboreal supports in gap-crossing movements such as leaping. Taking such anatomical differences imposed on the hand musculoskeletal system into consideration seems to be an important method of clarifying the mechanisms of precision grip in macaques.     

Plasma cholesterol levels in free-ranging macaques compared with captive macaques and humans

Plasma total cholesterol in free-ranging Japanese macaques (Macaca fuscata) on Koshima islet and in free-ranging long-tailed macaques (Macaca fascicularis) at Pangandaran in Indonesia was found to occur at very low levels compared with captive macaques and humans. Although total cholesterol levels in captive macaques were lower than humans, differences in HDL cholesterol levels were only small. In both sexes of wild and captive Japanese macaques, total cholesterol levels decreased from birth through to young adulthood but then increased in adult females of the captive group. In contrast, the value for adult females of the wild troop remained at a low level. Low TCH levels in adult females of the wild Japanese macaque troop may be due to a low energy intake and may have caused a delay in the onset of sexual maturation. Plasma TCH levels increased with the addition of 0.1% dietary cholesterol over six weeks in captive long-tailed macaques. That the cholesterol value after six weeks was dependent on cholesterol levels prior to supplementation indicates that captive macaques are slightly saturated with cholesterol.     

Preliminary observations of the Mentawai macaque on Siberut Island,Indonesia

During 2 years spent conducting ecological fieldwork on Siberut, the largest and most northerly of the four Mentawai Islands in Indonesia, incidental observations were made of the Mentawai macaque. The Mentawai macaque has been considered variously as a full species similar in some respects to the long-tailed macaque and as a subspecies of the pig-tailed macaque. Evidence is presented that a hitherto undescribed form of the Mentawai macaque occurs on Siberut, and aspects of its ecology and behavior are described.     

Locomotion and habitat use of Stampflii's putty-nosed monkey (Cercopithecus nictitans stampflii) in the Taï National Park, Ivory Coast

Stampflii's putty-nosed monkeys Cercopithecus nictitans stampflii are large, rare, poorly known guenons with a discontinuous distribution in West Africa. Putty-nosed monkeys occur at low densities in Ivory Coast's Tai National Park where they are believed to have migrated from less forested regions north of the park (Eckardt and Zuberbühler: Behav Ecol 15 (2004) 400-411). In this article, we compare the positional behavior of Putty-nosed monkeys to that of three other guenon species in the Tai Forest and provide an additional test of the relationship among locomotion, body size, maintenance activity, and habitat use in generalized arboreal quadrupeds. Our results indicate that putty-nosed monkeys confine the great majority of their locomotion to the main canopy where most movement occurs on boughs and branches. Comparison of overall locomotor frequencies across the four Tai guenon species reveals a general pattern; quadrupedalism accounts for at least 70% of the total profile, climbing ranges between 15 and 20%, and leaping accounts for 5-10% of total movement. The overall locomotor consistency among the taxa, especially between putty-nosed and Diana monkeys, is significant considering marked interspecific differences in support preference and strata use.     

Palmar and Plantar Pressure While Walking on a Horizontal Ladder and Single Pole in <Emphasis Type="Italic">Macaca fuscata</Emphasis>

To investigate biomechanical function in the hand and foot during quadrupedal locomotion in nonhuman primates, physical anthropologists and primatologists measure the pressure under them. We collected hand and foot pressure data while a Japanese macaque (Macaca fuscata), a semiterrestrial anthropoid, walked on 2 different simulated arboreal substrates, a horizontal ladder and a single pole, to explore differences in hand and foot use between the 2 substrates. The ladder rungs were perpendicular to the craniocaudal axis of the subject, and the pole was parallel to the subject’s craniocaudal axis. We tested the hypothesis that the pole was a more challenging substrate for the macaque than the ladder. Focusing on a diagonal sequence, diagonal couplets gait, we calculated gait characteristics and computed mean peak-pressure images of the hand and foot for each substrate from individual peak images via translation registration. We found several substrate differences that supported the hypothesis. The Japanese macaque walked at significantly slower speeds when traveling on the pole than on the ladder. Slower travel speed on the pole suggests that the Japanese macaque needed a wider support base to maintain balance on this substrate. Mean peak-pressure images suggest that the ladder invoked a more stepping-like behavior, but the pole invoked a more grasping-like behavior, especially of the foot. We show that the hand and foot use of the Japanese macaque would be adaptable to biomechanical challenges posed by different substrates.     

广西西南部石山森林中熊猴的姿势行为

灵长类动物姿势行为研究对了解其环境适应机制具有重要意义.2012年9月至2013年8月,采用瞬时扫描取样法对广西弄岗国家级自然保护区内一群熊猴(Macaca assamensis)的姿势行为进行观察,比较熊猴姿势行为的季节和日时段变化.结果 表明,熊猴移动模式的频率存在显著差异,从高到低为四足行走(45.3％±7.6％...     

Joint Loads in Marsupial Ankles Reflect Habitual Bipedalism versus Quadrupedalism

Joint surfaces of limb bones are loaded in compression by reaction forces generated from body weight and musculotendon complexes bridging them. In general, joints of eutherian mammals have regions of high radiodensity subchondral bone that are better at resisting compressive forces than low radiodensity subchondral bone. Identifying similar form-function relationships between subchondral radiodensity distribution and joint load distribution within the marsupial postcranium, in addition to providing a richer understanding of marsupial functional morphology, can serve as a phylogenetic control in evaluating analogous relationships within eutherian mammals. Where commonalities are established across phylogenetic borders, unifying principles in mammalian physiology, morphology, and behavior can be identified. Here, we assess subchondral radiodensity patterns in distal tibiae of several marsupial taxa characterized by different habitual activities (e.g., locomotion). Computed tomography scanning, maximum intensity projection maps, and pixel counting were used to quantify radiodensity in 41 distal tibiae of bipedal (5 species), arboreal quadrupedal (4 species), and terrestrial quadrupedal (5 species) marsupials. Bipeds (Macropus and Wallabia) exhibit more expansive areas of high radiodensity in the distal tibia than arboreal (Dendrolagus, Phascolarctos, and Trichosurus) or terrestrial quadrupeds (Sarcophilus, Thylacinus, Lasiorhinus, and Vombatus), which may reflect the former carrying body weight only through the hind limbs. Arboreal quadrupeds exhibit smallest areas of high radiodensity, though they differ non-significantly from terrestrial quadrupeds. This could indicate slightly more compliant gaits by arboreal quadrupeds compared to terrestrial quadrupeds. The observed radiodensity patterns in marsupial tibiae, though their statistical differences disappear when controlling for phylogeny, corroborate previously documented patterns in primates and xenarthrans, potentially reflecting inferred limb use during habitual activities such as locomotion. Despite the complex nature of factors contributing to joint loads, broad observance of these patterns across joints and across a variety of taxa suggests that subchondral radiodensity can be used as a unifying form-function principle within Mammalia.     

Positional behavior ofCebuella pygmaea in Yasuni National Park, Ecuador

In terms of positional behavior, the small-bodied callitrichids are distinguished from other anthropoids by their ability to leap between and to cling to large vertical supports, feeding occasionally or frequently on sap and bark insects. In this paper, I studied the positional behavior of a group of pygmy marmosets in a hilly wet tropical forest in Yasuni National Park, Ecuador. During traveling, the animals used quadrupedal walk/bound and leaping mostly on small horizontal supports. During foraging, quadrupedal walk/bound and clambering dominated. The main foraging postures were stand and cantilever, occurring mainly on small horizontal lianas. During feeding, scansorial locomotion was used very frequently. Claw clinging was the dominant feeding posture. Furthermore, large vertical lianas and tree boles were the most frequent feeding supports. These observations would suggest that scansorial locomotion, vertical clinging, and vertical leaping are most likelynot part of the same form function complex. Vertical leaps appear to be associated with moving in the lower parts of the forest. On the other hand, scansorial locomotion and vertical clinging appear to be related to feeding on the sap of tree boles and large lianas in the lower parts of the forest.