The Old World Monkeys; newcomers

It's been quite some time now since I introduced the wonderful South American monkeys, and I've been intending ever since to balance things by talking about the 'other' monkeys, the ones that stayed behind in Africa and Asia. Now's the time - but first I'd better correct that last sentence!

We know that the South American monkeys left Africa (doubtless unwillingly, and quite likely on more than one occasion) some 35 million years ago, and rafted to South America, and it's logical to suppose that these pioneers were typical of the monkeys we now associate with Africa. However life is rarely that simple. When the raft set out across the Atlantic it would have carried with it small, possibly lemur-like animals. The ancestors of the Old World monkeys and the apes (the catarrhines, for the record) only differentiated from the 'lemur-likes' and bushbabies in Africa around 28-29 million years ago; the split of monkeys from apes occurred about 25 million years ago. This all means that, despite our insistence that apes are not monkeys, the apes and Old World Monkeys form a coherent group, being considerably more closely related to each other than either is to the New World Monkeys. (Sorry, but that's been messing with my head while I've been putting this together, and I might as well share it with you!)

So, what characterises the family Cercopithecidae (ie the Old World Monkeys, or OWM from now on)? The obvious difference between them and the other catarrhines - ie the apes - is the presence of a tail. The most obvious distinction between them and the New World Monkeys (which comprise five families) is that the OWMs have narrow nostrils, close together and often down-pointing, and leathery buttock pads for sitting on; they do not have prehensile (grasping) tails.

Olive Baboon Papio anubis, Murchison Falls NP, Uganda. The narrow nose with down-facing nostrils and
non-grasping tail are evident; the buttock pads are just visible, but see below for a better view.

And no, neither she nor I had anything to do with the bottles! Lake Mburo NP, Uganda.

There are some 160 species in the family, found across much of Africa and south and south-east Asia. (Though this is based on recent taxonomic understandings - older texts cite significantly lower numbers.) They are fundamentally divided, quite evenly, into two sub-families, which many would raise to full family status. The division is pretty well characterised by diet; the cheek-pouched monkeys (Cercopithecinae) have a wide diet, but are mostly fruit-eaters, while the leaf monkeys (Colubinae), obviously enough, mostly eat foliage. Both sub-families are represented in Asia and Africa. In turn both are further divided into two tribes, but before you give up in despair, I think I'll just introduce you to some members of the groups, with sub-headings to help us out!

Cheek-pouch Monkeys; baboons, macaques and mangabeys (Papionini)

The two tribes separated about 10 million years ago. This group dominates in sub-Saharan Africa, though is well-represented in Asia by the prominent macaques. Most of the members are solidly-built ground-dwellers, some with short tails.

Chacma Baboon Papio ursinus, Augrabie Falls NP, South Africa.
Aside from the related Drill and Mandrill, this is the largest of all monkeys, weighing up to 40kg.
It is a formidable animal, made more so by living in big ground-foraging groups.
Baboons live across much of Africa; this species is found in the far south, while the Olive Baboon,
featured above, is found across central Africa.

Long-tailed Macaques Macaca fascicularis, Pulau Tiga, Sabah, above and below.
This species is found across south-east Asia and Indonesia, where it can become a close associate with humans.
This can lead to aggressive demands for food. The group comprises females, with a strict hierarchy,
and young animals.

Cheeky youngsters.
Males must leave the group at puberty.

Southern Pig-tailed Macaque Macaca nemestrina, Gomantong, Sabah.
There are 23 species of macaques, including several with short tails.
This species has both male and female hierarchies within the group.

Grey-cheeked Mangabey Lophocebus albigena, Kibale NP, Uganda.
This is a forest monkey from central Africa. There are several males in the group, but none are dominant.
Interestingly, young males are forced to leave the group and join another,
but females live their lives in the group they were born to.

Cheek-pouch Monkeys; guenons (Cercopithecini)

This tribe comprises mostly tree-dwelling, lightly built cheek-pouch monkeys.

Red-tailed Monkeys Cercopithecus ascanius, Mabira Forest, Uganda.
A monkey of the tropical forests of central Africa, where it lives in groups of up 30,
with a dominant male, females and youngsters.

L'Hoest's Monkey Cercopithecus lhoesti, Bwindi Impenetrable NP, Uganda,
a beautiful tree-dwelling monkey of mountain forests in the Congo, Rwanda, Burundi and Uganda.
The female-dominated group contains only one male.

Vervet Monkey Chlorocebus pygerythrus, Entebbe NP, Uganda.
A common and familiar monkey of eastern and southern Africa, which often
comes into conflict with humans by raiding crops.

Patas Monkey Erythrocebus patas, Waza NP, northern Cameroon.
This is an unusually terrestrial monkey for its tribe, living in open, often semi-arid, habitats.
It usually lives in large groups but this female had an injured front leg and was on her own with the baby.
They are reputedly the fastest across the ground of all monkeys.

Northern (or Guinea) Talapoin Miopithecus ogouensis, Sanaga River, Cameroon,
a small riverine forest monkey found from Cameroon south through Equatorial Guinea.
The two talapoin species are the smallest of the Old World Monkeys, weighing little more than a kilogram.
They live in parties of up to 100.

Leaf Monkeys; African colobines (Colobini)

The leaf monkeys have complex chambered stomachs with bacterial colonies for the digestion of leaves. The greatest diversity of leaf monkeys is found in Asia, but 23 species are found across Africa. These comprise the colobus monkeys, striking monkeys which may be the most beautiful of all. Unlike their Asian counterparts they are strictly tree-dwellers and impressive aerialists. 

Guereza Colobus (or Mantled Guereza) Colobus guereza, Queen Elizabeth NP, Uganda.
This stunning monkey is found across central Africa from Nigeria to Ethiopia and Tanzania.
As here, they prefer riverside forests, and secondary to primary forest.
They will supplement their leaf diet with fruit on occasion.

Leaf Monkey; Asian colobines (Presybitini)

There are over 50 species of Asian leaf-eating monkeys, including some rare and little-known species, and one of the best-known and most unusual monkeys. We'll start with a couple of less familiar, but very beautiful, members of the tribe.

Maroon Leaf Monkey Presbytis rubicunda, Gomantong, Sabah.
A gloriously-coloured medium-sized monkey from the lowland rainforests of Borneo.

Silvered Leaf Monkey (or Lutung) Trachypithecus cristatus, Labuk Bay, Sabah.
This is a larger monkey than the previous species and uses a different habitat, found along rivers and
in mangroves and eating more and tougher leaves than other species.
They are strongly arboreal, but at Labuk Bay they have been habituated to come to feeding tables,
along with Proboscis Monkeys.

Silvered Leaf Monkeys, Bako NP, Sarawak.
Babies are born bright orange, and fade to adult colour over five months.
As well as Borneo they are found in Sumatra and a small part of peninsular Malaysia.

I'll end with a truly charismatic monkey, the amazing Proboscis Monkey Nasalis larvatus of Borneo, a big leaf-eating mangrove specialist with a huge leaf-digesting gut and the eponymous male nose, which acts as a resonating chamber for his honking display calls.

Male, Labuk Bay, Sabah.
Endemic to Borneo, it is also the only member of its genus.
A male like this can weigh up to 30kg, making it one of the largest Asian monkeys.
They are regular and competent swimmers.

Youngsters playing, Labuk Bay.

Eating mangrove leaves, Bako NP, Sarawak.

This really is a very colourful monkey!

Labuk Bay. Adult males are more cautious, but young animals are good aerialists.

So, a brief introduction to the Old World Monkeys; I hope you've met some and learnt something that you didn't know. As ever though, there's no substitute for seeing them for yourself! Thanks for reading.

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