Geoffroy's spider monkey
Ateles geoffroyi
— Where the name comes from
Ateles is the Greek atelḗs, “incomplete, imperfect”: whoever named it noticed that the hands lack a thumb, reduced to a stub or missing altogether, and judged the animal to be short of something. Geoffroyi recalls Étienne Geoffroy Saint-Hilaire again. The common name, spider monkey, comes from the four very long limbs plus the tail, which at a distance make the animal look like a moving web.
— Facts
- Group
- Mammals · Mammalia
- Order
- Primates
- Habitat
- High canopy of rainforest and semi-deciduous forest
- Range
- From southern Mexico to Panama and north-western Colombia
- Size
- 30–63 cm of body plus 63–85 cm of tail, 6–9 kg
- Diet
- Frugivore — ripe fruit for over 80% of the diet
- Lifespan
- 25 years in the wild, up to 40 in captivity
— Characteristics
- 01
The prehensile tail has a bare tip with skin ridges like fingerprints.
- 02
The thumb is absent: the hand works as a hook that slides better among branches.
- 03
It lives in fission-fusion societies, with subgroups that form and dissolve every day.
— What sets it apart
The missing thumb is not a defect but a specialisation: without it the hand becomes a clean hook that catches and releases branches at speed, and that is what an animal moving by swinging on its arms needs. In its place it has developed a fifth hand, the tail: the tip is hairless, covered in skin ridges like our fingertips, and is sensitive and precise enough to pick a single fruit. It has lost a finger and gained a limb.
