“…Studies on non-human primates have shown that they may respond to a reduction in food availability by incorporating scarce but high-return foods or by optimizing their food intake on abundant but low-quality food [Hill et al, 2003;Sayers & Norconk, 2008;Tsuji et al, 2013;van Doorn et al, 2010;Wrangham et al, 1998]. The strategy they adopt may lead them to a diet including low profitability (e.g., energy/handling time) items (like Himalayan gray langurs, Semnopithecus entellus, in winter [Sayers et al, 2010] Most species of primates exhibit some degree of diet flexibility that allows them to cope with seasonality of resource availability or with intersite differences of habitat quality due to altitude, latitude, habitat fragmentation/loss, or habitat degradation [Campbell-Smith et al, 2011;Chaves & Bicca-Marques, 2013;Chaves et al, 2012;NaughtonTreves et al, 1998;Quéméré et al, 2013;Riley, 2007;Singh et al, 2001;Tsuji et al, 2013;Xiang et al, 2007]. Even species broadly and stereotypically described as dietary specialists are able to modify their dietary composition in response to habitat change (folivores such as colobines, [Grueter et al, 2009b;Koenig & Borries, 2001;Sayers & Norconk, 2008;Sayers et al, 2010;Xiang et al, 2007], or frugivores [Russo et al, 2005;Wieczkowski & Kinnaird, 2008]).…”