Monkey Facts & Species, Monkey Species
Monkeys With Long Tails: Species, Records and What Tails Are For
Some monkeys carry a tail longer than the rest of their body. In spider monkeys and long-tailed macaques the tail can exceed the head-and-body length by a third, and in a handful of New World species it functions as a genuine fifth limb capable of gripping, hanging and even picking up fruit.
Key takeaways
- Spider monkeys have the longest tails relative to body size — up to 90 cm on a 50 cm body.
- Only four New World genera have fully prehensile tails: howler, spider, woolly and muriqui.
- No Old World monkey can grip with its tail.
- Long tails are mainly balance organs for running along branches and correcting mid-leap.
- Ground-dwelling and short-range species such as macaques on Sulawesi have reduced tails to stubs.
Monkeys with the longest tails
| Species | Tail length | Tail type |
|---|---|---|
| Spider monkey | 60-90 cm | Fully prehensile |
| Woolly monkey | 60-72 cm | Fully prehensile |
| Howler monkey | 55-75 cm | Fully prehensile |
| Long-tailed macaque | 40-65 cm | Non-prehensile |
| Black-and-white colobus | up to 100 cm | Non-prehensile, plumed |
| Squirrel monkey | 35-45 cm | Non-prehensile, balancing |
| Common langur | up to 100 cm | Non-prehensile |
The colobus deserves a mention of its own: its long white plumed tail acts as a rudder and parachute during the enormous leaps it makes between trees.
How a prehensile tail works
A prehensile tail has extra vertebrae, powerful muscles and — critically — a bare patch of ridged skin on the underside near the tip, packed with nerve endings and friction ridges much like a fingerprint. Brain scans show this tail pad has its own large area of somatosensory cortex, comparable to that devoted to a hand. That is why a spider monkey can hang by the tail while both hands work, or use the tail to pluck a single fruit. See Spider Monkey Facts and Why Monkeys Swing Through Trees.
Capuchins are the intermediate case: their semi-prehensile tail can coil for support but lacks the bare pad and cannot bear full weight for long. See Capuchin Monkey Facts.
What long tails are actually for
- Balance while running along narrow branches.
- Mid-air correction — swinging the tail rotates the body during a leap.
- Bracing against a branch to free the hands for feeding.
- Signalling — tail position communicates mood and rank in many species.
- Reaching food on branches too thin to support body weight.
More detail in Why Monkeys Have Tails.
Monkeys with almost no tail
Tails are expensive to grow and carry, so species that spend most of their time on the ground tend to lose them. Barbary macaques have only a vestigial stub, Sulawesi crested macaques are effectively tailless, and stump-tailed macaques have a short thick remnant. This is a good reminder that “tail equals monkey” is a rule of thumb rather than a law — see Monkeys vs Apes.
Frequently asked questions
Which monkey has the longest tail?
Relative to body size, the spider monkey. In absolute length, some colobus and langur tails approach a metre.
Can monkeys hang by their tails?
Only howler, spider, woolly and muriqui monkeys can support their full weight by the tail.
Do Old World monkeys have prehensile tails?
No. Prehensile tails evolved only in the New World.
Why do some monkeys have no tail?
Ground-dwelling species gain little from a tail and lose it over evolutionary time.
Can a monkey feel with its tail?
Yes. Prehensile tail tips have dense touch receptors and a dedicated area of the brain.
Related: Monkey Adaptations, Arboreal Monkeys, Ultimate Guide to Monkeys.
