吃绿色蔬菜绝对是一件很累的事，特别当你是一只以高纤维植物为食的猴子时。
通过在消化道中寄存大量微生物以分解不易咀嚼的树叶——就像牛那样，一些灵长类动物克服了它们的消化困境。
为了最有效地利用每一顿饭，牛和其他反刍动物通过反刍和再咀嚼其胃容物从而使这种共生关系最大化。
这种行为曾被认为是四足食草动物所特有的。如今，研究人员证实，栖息在婆罗洲红树林与沼泽中的长鼻猴（如上图）也有相同的行为。
这是灵长类动物反刍的首个证据，并且其中的科学价值很值得人们仔细玩味。
研究人员在3月29日的《生物学快报》网络版上报告了这一发现。（生物谷Bioon.com）
生物谷推荐英文摘要：
Biol. Lett. doi: 10.1098/rsbl.2011.0197
Regurgitation and remastication in the foregut-fermenting proboscis monkey (Nasalis larvatus)
Ikki Matsuda1,*, Tadahiro Murai1, Marcus Clauss2, Tomomi Yamada3, Augustine Tuuga4, Henry Bernard5 and Seigo Higashi6
Although foregut fermentation is often equated with rumination in the literature, functional ruminants (ruminants, camelids) differ fundamentally from non-ruminant foregut fermenters (e.g. macropods, hippos, peccaries). They combine foregut fermentation with a sorting mechanism that allows them to remasticate large particles and clear their foregut quickly of digested particles; thus, they do not only achieve high degrees of particle size reduction but also comparatively high food intakes. Regurgitation and remastication of stomach contents have been described sporadically in several non-ruminant, non-primate herbivores. However, this so-called ‘merycism’ apparently does not occur as consistently as in ruminants. Here, to our knowledge we report, for the first time, regurgitation and remastication in 23 free-ranging individuals of a primate species, the foregut-fermenting proboscis monkey (Nasalis larvatus). In one male that was observed continuously during 169 days, the behaviour was observed on 11 different days occurring mostly in the morning, and was associated with significantly higher proportions of daily feeding time than on days when it was not observed. This observation is consistent with the concept that intensified mastication allows higher food intake without compromising digestive efficiency, and represents an expansion of the known physiological primate repertoire that converges with a strategy usually associated with ruminants only.
