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ABSTRACT There are at present few comparable studies of lemur locomotion in the wild. This has unfortunately meant we have little knowledge about locomotor variation, and hence flexibility, with regard to differences in support availability and habitat structure. Here we compare the locomotion of Lepilemur edwardsi at Ankarafantsika with that of Lepilemur ruficaudatus at Kirindy-Mitea National Park. While data were collected by two individuals, at different times, both studies used the same data collection protocol and are hence highly comparable. Locomotor mode, support diameter and orientation, heights, and distances traveled were all collected. We find that locomotor specialization, in this case for vertical leaping, has ensured that some support requirements are independent of habitat. For example, both species used vertical supports most often. However, overall support diameter does indicate a certain degree of flexibility, whereby L. ruficaudatus most often used supports ≤5 cm in diameter and L. edwardsi >5 cm in diameter. Am J Phys Anthropol 156:58-66, 2015 © 2014 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Metabolic costs of resting and locomotion have been used to gain novel insights into the behavioral ecology and evolution of a wide range of primates; however, most previous studies have not considered gait-specific effects. Here, metabolic costs of ring-tailed lemurs ( Lemur catta) walking, cantering and galloping are used to test for gait-specific effects and a potential correspondence between costs and preferred speeds. Metabolic costs, including the net cost of locomotion (COL) and net cost of transport (COT), change as a curvilinear function of walking speed and (at least provisionally) as a linear function of cantering and galloping speeds. The baseline quantity used to calculate net costs had a significant effect on the magnitude of speed-specific estimates of COL and COT, especially for walking. This is because non-locomotor metabolism constitutes a substantial fraction (41-61%, on average) of gross metabolic rate at slow speeds. The slope-based estimate of the COT was 5.26 J kg−1 m−1 for all gaits and speeds, while the gait-specific estimates differed between walking (0.5 m s−1: 6.69 J kg−1 m−1) and cantering/galloping (2.0 m s−1: 5.61 J kg−1 m−1). During laboratory-based overground locomotion, ring-tailed lemurs preferred to walk at ∼0.5 m s−1 and canter/gallop at ∼2.0 m s−1, with the preferred walking speed corresponding well to the COT minima. Compared with birds and other mammals, ring-tailed lemurs are relatively economical in walking, cantering, and galloping. These results support the view that energetic optima are an important movement criterion for locomotion in ring-tailed lemurs, and other terrestrial animals. Am J Phys Anthropol, 2012. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

In many primate species, hands and feet are large relative to neonatal body weight, and they subsequently exhibit negative allometric growth during ontogeny. Here, data are presented showing that this pattern holds for a wild population of lemur, Verreaux's sifaka (Propithecus verreauxi verreauxi). Using morphometric data collected on this population, it is shown that younger animals possess relatively large hands and feet. This ontogenetic pattern suggests a simple behavioral test: do juvenile animals with their larger, almost adult-sized hands and feet locomote on similarly sized substrates as adult animals? Using locomotor bout sampling, this question was tested by collecting positional behavior data on this population. Results from this test find no differences in locomotor behaviors or substrate use between yearlings and adult animals. To place these results in a broader evolutionary context, heritabilities and selection gradients of hands, feet, and other limb elements for animals in this population were estimated. Among limb elements, heritabilities range from 0.16- 0.44, with the foot having the lowest value. Positive directional selection acts most strongly on the foot (directional selection gradient = 0.119). The low heritability and positive selection coefficient indicate that selection has acted, and continues to act, on foot size in young animals. These results are interpreted within a functional context with respect to the development of locomotor coordination: larger feet enable young animals to use "adult-sized" substrates when they move through their habitat. It is suggested that the widespread pattern of negative allometry of the extremities in sifaka and other primates is maintained by selection, and does not simply reflect a primitive developmental pathway that has no adaptive basis. [ABSTRACT FROM AUTHOR]