#colobus

shores of Zanzibar

This Zanzibar Red Colobus (they/them) helps the farmers harvest seaweed.

The farmers keep them around because they pick off imperfections and small creatures hiding the seaweed. Sometimes, though, the colobus eats what the women harvest.

Western Red Colobus Piliocolobus badius

A monkey from West African forests from Senegal to Ghana. The red colobus lives in colonies of between twelve and eighty members. There are usually several males and up to three times this number of adult females.

I'm not saying people need to start calling apes monkeys or anything, but if you're the kind of person to say "that's not a monkey, that's an ape", you are technically wrong.

A lot of people say that "if it has a tail, it's a monkey. If it doesn't, it's an ape" but frankly that's getting into "featherless biped" territory.

This is a barbary macaque. If you don't look at its waist, you'll probably not at all think it's an ape - and you'd be right - it isn't an ape at all. However, barbary macaques don't have tails, though all of their relatives do.

So, what actually defines an ape? It's mostly about the torso actually!

Apes are more defined by having a more wide and shallow torso, while other monkeys have a narrower and deeper torso. Also, apes have shoulder blades on the back rather than on the side, and a greater range of mobility of the shoulders.

These adaptations were likely originally to allow for brachiation (swinging between branches and trees using the arms), which is still the dominant form of movement in gibbons

OK, so if that's why apes and monkeys are different, why did you say that apes ARE monkeys? Well, Simiiformes, the infraorder that contains the monkeys (including apes) is split into two parvorders: Platyrrhini and Catarrhini.

Here's an example of some Platyrrhines or "New World monkeys":

Now, here's some Catarrhines, or "Old World monkeys":

As you can see, apes are nestled within the Catarrhines. The differences between Platyrrhines and Catarrhines are:

Platyrrhines are native to the Americas, while Catarrhines are native to Africa and Asia (and formerly Europe)

Platyrrhines have more sideways-facing nostrils, while Catarrhines have more downward-facing nostrils

Platyrrhines have 12 premolars (3 on each side of each jaw), while Catarrhines have 8 (2 on each side of each jaw)

Platyrrhines are usually smaller, ranging between 14-70cm (5.5-28in) in adult size and 0.12-15kg (0.26-33lb) in adult weight while Catarrhines are usually larger, ranging between 34-195cm (13-77in) and 0.7-219kg (1.5-483lb) (this is just in terms of living species and not including humans)

Some platyrrhines (specifically spider monkeys, howler monkeys, woolly monkeys, and capuchins) have prehensile tails, while Catarrhines do not

Platyrrhines do not have opposable thumbs (with the exception of capuchins and squirrel monkeys, which have semi-opposable thumbs), while Catarrhines do (with the exception of colobuses, which lack thumbs entirely)

Most platyrrhines are dichromatic (seeing two wavelengths of light) (with the exception of howler monkeys, which are trichromatic, and trichromancy exists as a female-only recessive gene in other platyrrhines), while catarrhines are trichromatic (seeing three wavelengths of light)

If both New World and Old World monkeys are monkeys to you, then apes should be as well.

Image credits:

Barbary macaque: Errol Véla @ abounabat on iNaturalist

Black-and-gold howler monkey: Carlos Schmidtutz @ carlossch on iNaturalist

Central American squirrel monkey: Michelle Monge-Velazquez @ mich_croc on iNaturalist

Bald uakari: @ sea-kangaroo on iNaturalist

Black-striped capuchin: Marcos Halem Felix @ marcosfelix_birdscuiaba on iNaturalist

Central American squirrel monkey: Roger Woodruff @ rdwoodruff on iNaturalist

Formosan rock macaque: Jurga Motiejūnaitė @ jurga_li on iNaturalist

Mountain gorilla: Laura Keene @ laurakeene on iNaturalist

Eastern chimpanzee: Ad Konings @ adkonings on iNaturalist

Udzungwa red colobus & Yellow baboon: Zein et Carlo @ lesbectrotters on iNaturalist

Angola Colobus Colobus angolensis