Locomotor Flexibility in Lepilemur Explained by Habitat and Biomechanics Mary L. Blanchard, 1 * Simon Furnell, 2 William I. Sellers, 2 and Robin H. Crompton 1 1 Musculoskeletal Biology II, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool L69 3GA, UK 2 Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK KEY WORDS Madagascar; support diameter; leaping; lemur ABSTRACT There are at present few comparable studies of lemur locomotion in the wild. This has unfortu- nately 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 Ankar- afantsika 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 ori- entation, heights, and distances traveled were all col- lected. 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 sup- ports 5 cm in diameter and L. edwardsi >5 cm in diam- eter. Am J Phys Anthropol 156:58–66, 2015. V C 2014 Wiley Periodicals, Inc. Locomotion interacts with many ecological and life vari- ables: it enables animals to access food, to avoid becoming prey, and to find a mate (Cant, 1992). Hence understand- ing an animal’s locomotion is vital to knowledge on its ability to survive and reproduce. Primate locomotion is especially interesting, partly as a consequence of being from one of the most ancient mammalian Orders and as one of the least specialized in postcranial morphology, and living primates use an unusually great range of locomotor modes, from terrestrial quadrupedalism through arboreal brachiation, (see e.g., Fleagle, 1977; Fleagle and Mitter- meier, 1980). Thus, primate locomotion can tell us much about evolution and niche separation. Most research on primate locomotion comes out of the captive environment and this is especially good for obtaining well-controlled data. If we examine captive studies on lemurs, we find studies on Eulemur rubri- venter (Tilden, 1990), Propithecus verreauxi (Wunderlich and Schaum, 2007), Lemur catta (Demes et al., 2006), and others on multiple species (Terranova, 1996; Demes et al., 1999, 2005). These studies are valuable for obtain- ing actual pressure and force readings difficult to obtain in the wild, but none of these studies take into account habitat and ecology. An animal’s maximum locomotor performance capability is rarely expressed in its daily locomotion, and hence mean recorded displacement tends to fall far short of these maxima. For example, wild Pro- pithecus diadema can leap 7 m, but their mean leap length on vertical supports is only 2.3 m (Blanchard, 2007). Thus, a study carried out in captive conditions might well find that P. diadema can leap 7 m, but this does not inform us about the leap lengths typically used in the wild during travel or foraging. Thankfully there is a growing body of work on the locomotion of wild lemur species (Dagosto, 1989; Dagosto, 1995; Demes et al., 1996; Warren, 1997; Dagosto and Yamashita, 1998; Raza- fimanantsoa, 1999; Blanchard, 2007). The locomotion of Lepilemur has long been compared to that of the indriids (Rand, 1935; Petter, 1962) and it was classified by Napier and Walker (1967) as a vertical clinger and leaper alongside the indriids, Hapalemur, Tar- sius, Galago, and Euoticus. While there are observable morphological differences among these genera, they all share elongated hindlimbs, relative to forelimbs, and it is these hindlimbs that power leaping (Napier and Walker, 1967). As one would expect from their locomotor classifica- tion, these species are usually observed with a vertical, orthograde, body posture. The most common mode of travel is vertical leaping, and comparing studies that uti- lize comparable methodology, we see leaping accounts for 66% of all bouts in Avahi (Warren and Crompton, 1997) and up to 81% in Indri (Blanchard, 2007). Dagosto and Yamashita (1998), using slightly different methods, found even higher rates of leaping for P. diadema of 85%. Fur- ther, vertical supports are preferred, for example used in 42% of bouts in Avahi (Warren and Crompton, 1997) and 55% in P. diadema (Blanchard, 2007). Such primate studies are increasing our understanding of the importance of influences outside of skeletal and muscular adaptations, such as habitat, which affect loco- motor behavior. For example, Manduell et al. (2012) found forest structure and support availability strongly Grant sponsor: The Leverhulme Trust; Grant number: F/00 025/AK. *Correspondence to: Mary Blanchard, Musculoskeletal Biology II, Duncan Building, Daulby St, University of Liverpool, Liverpool, L69 3GA, UK. E-mail: mary.blanchard@liv.ac.uk Received 2 June 2014; accepted 15 September 2014 DOI: 10.1002/ajpa.22627 Published online 26 September 2014 in Wiley Online Library (wileyonlinelibrary.com). Ó 2014 WILEY PERIODICALS, INC. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 156:58–66 (2015)