There have never been enough primates on Tet Zoo. That isn’t because I’m not interested in primates, nor because I don’t think about primates, or look at primates, that much... in fact, I probably think about, and look at, primates more than I do any other group of animals... it’s simply because – as is the case for so many tetrapod groups – I’ve just never yet had the time to do them justice. I recently went to Howletts Wild Animal Park (Kent, UK) where I watched, and photographed, several primates I haven’t seen much, or at all, before. And here we have a good excuse to talk, briefly, about a select few primates. Let’s see how it turns out.

I’ve never seen a Lion-tailed macaque or Wanderoo Macaca silenus until my recent trip to Howletts. Unique to the Western Ghats in India, the Lion-tailed macaque is black-bodied and has a silvery mane and tufted tail-tip... you’d think that the mane would be the key feature of interest, not the tail, but, whatever. It’s substantially more arboreal than other macaques and is a generalist herbivore/omnivore that feeds on a variety of plants, also occasionally eating birds and their eggs.

Macaques are a large and complex group of monkeys and there have been various efforts to determine their phylogeny and evolutionary history. It seems that the Lion-tailed macaque is especially close to the Southern pig-tailed macaque M. nemestrina, the two belonging to a wholly east Asian group that also includes the Celebes crested macaque C. nigra (Morales & Melnick 1998, Li et al. 2009). Lion-tailed macaques are among the world’s most threatened primates, with the world population currently numbering less than 3500. The spread of agriculture and the construction of dams, reservoirs and roads across their range has led to them being increasingly split into smaller, more fragmented populations.

I won’t talk about the Celebes crested macaque (or Celebes black macaque, or Sulawesi crested macaque) right now since there’s so much to say about them.

This is a Guereza or Mantled guereza Colobus guereza, the best known of the five or so Colobus species, sometimes collectively termed the pied or black-and-white colobuses. There are several different views on the taxonomy and phylogeny of this group (e.g., Groves 2007). Excepting the all-black Black colobus C. satanas, all are black and white, often with long white tassels on their shoulders, flanks and tails and white regions on their faces and thighs. The entire radiation is exclusively African and largely limited to the tropical and subtropical forests of central Africa. Like other colobines, pied colobuses have multi-chambered stomachs and are forest-dwelling herbivores that subsist mostly on leaves, though they also eat fruit, flowers, seeds and buds. The name ‘colobus’ comes from the French ‘colobe’ or the Greek ‘kolobos’ (take your pick) meaning ‘mutilated’, an idea inspired by the reduction of the thumb to just a small tubercle. Thumbs are over-rated: they've been lost or reduced in gibbons and spider monkeys, too.

Black and white colobuses have peculiar noses where soft tissue forms an elongate, almost human-like proboscis that approaches the upper lip (cough cough add appropriate comment about human-type nose and AAH cough cough). They’re large, reaching about 1 m in total length and with males exceeding 20 kg. Like so many monkeys, they’re flamboyant, showy animals. They live in small social groups dominated by large, highly vocal males who advertise their presence with loud nocturnal and dawn roaring choruses. They are threatened by habitat loss and hunting for both their pelts and meat.

These [above] are female Gelada Theropithecus gelada engaging in an aggressive encounter with other members of their group, hence their weird appearance: they’re performing the ‘lip flip’ behaviour unique to this species. Male Geladas are splendid monkeys with long, flowing manes and long, tufted tails. The species is endemic to the central Ethiopian highlands.

Geladas are among the most remarkable of monkeys, being highly specialised for terrestrial grazing. Closely related to baboon-mangabeys, baboons and the Kipunji Rungwecebus kipunji (Davenport et al. 2006), just about all of their anatomical peculiarities are related in some way to their terrestriality, grazing lifestyle, or ‘shuffle feeding’ form of behaviour. These include especially tall-crowned teeth, proportionally elongate forearms and thumbs, larger bodies and especially flexible elbows and wrists [Jonathan Kingdon has proposed that the human lineage went through a similar so-called 'squat foraging' phase in its evolution. Interesting, but not widely accepted]. The presence of colourful skin patches on the chest, used in advertising sexual status, has also been linked to shuffle feeding (Kingdon 1997), since the fact that they spend most of their time sat on their rumps means that the buttocks and genitals are not on display as they are in most other monkeys. Indeed, the buttock pads (or ischial callosities, whichever you prefer) are black, not red. An oft-mentioned fact about Geladas is that the living species is the only surviving member of a once more widespread group that contained several species, some of which were substantially bigger than the living one.

As usual, there is tons more I’d like to say. But my time is up. All of the primates discussed here are members of the Old World monkey group Cercopithecidae.

For previous Tet Zoo articles on Old World monkeys and other primates, do check out...

Refs - -

Davenport, T. R. B., Stanley, W. T., Sargis, E. J., De Luca, D. W., Mpunga, N. E., Machaga, S. J. & Olson, L. E. 2006. A new genus of African monkey, Rungwecebus: morphology, ecology, and molecular phylogenetics. Sciencexpress 10.1126/science.1125631

Groves, C. P. 2007. The taxonomic diversity of the Colobinae in Africa. Journal of Anthropological Sciences 85, 7-34.

Jablonski, N. G. 1993. Theropithecus: The Rise and Fall of a Primate Genus. Cambridge University Press, Cambridge, UK.

Li, J., Han, K., Xing, J., Kim, H. S., Rogers, J., Ryder, O. A., Disotell, O. A., Yue, B. & Batzer, M. A. 2009. Phylogeny of the macaques (Cercopithecidae: Macaca) based on Alu elements. Gene 448, 242-249.

Kingdon, J. 1997. The Kingdon Field Guide to African Mammals. Academic Press, San Diego.

Morales, J. C. & Melnick, D. J. 1998. Phylogenetic relationships of the macaques (Cercopithecidae: Macaca), as revealed by high resolution restriction site mapping of mitochondrial ribosomal genes. Journal of Human Evolution 34, 1-23.