Monkey Business- hanging with spiders

Watching spider monkeys play is a delight. A youngster will watch an adult’s tail, suddenly bite it and run away. In return, adults sometimes chastise the young with a slap. On occasion, all play a kind of tag in which they chase an individual until it is caught, the runs off after the others in hot pursuit until it manages a grab or a playful bite. And so it will go on.

Spider Monkeys has longer limbs than any other primate. Its tail is an efficient fifth limb that can grab with surprising strength. It often uses it to hang onto a branch so that its hands are free to get a fruit beyond normal reach. It moves from tree to tree with exceptional speed, by brachiating- swinging arm over arm- with fluid grace and timing.

Asa young spider money start to move about alone (a risky time), the tail is used in a special way. When the next tree is a bit too far for an infant to leap to, the adult female (seldom males) holds one branch with her hands and the other with a tail, spanning gaps as much as three metres wide. The infant the scrabbles across the “furry bridge” holding onto the adult’s long hair.

When rains start, the monkeys spend their time sheltering as best they can. Their thick shaggy coats could seem to shed rain well unless a deluge goes on all day. In this case, they huddle together, except for the guard male who is usually some distance away from where he has a good view of the vicinity.

Only two factors significantly alter the monkey’s normal pattern of behaviour; heavy rain or the presence of a predator.

This time the guard detected danger, and started “cough-call”, intently looking in the direction of the danger. The rest of the group shook the branches with arms and legs, faces displaying real anger. They used their long, grasping tails to anchor them securely to the branches. The dominant female started echoing the guard’s male shouts in a duet while the rest of the group screamed and called and called ear-deafeningly loud! This time the cause of the alarm was a harpy eagle perched on a nearby tree with a clear view of the monkeys. Apart from humans, this bird must be the biggest danger the monkeys face.

Forest people regard monkeys, especially the large ones, as prize food. Where there are shotguns, monkeys of any kind are hard to find, having long moved away or become totally extinct. In rainforests where Indians still hunt with traditional weapons such as blowpipes, the monkeys exist in seemingly healthy numbers.

Interesting Facts

• Spider monkeys are considered to be very intelligent. They have large brains for their body size and they use specific signals and vocalisations to alert about the perceived danger. Many species scent-mark and most are territorial.
• The spider monkey’s most obvious feature is its tail. Prehensile and extremely powerful, it acts as a fifth limb helping the monkey feed, moves and even mates. One species has been seen to use it to collect water from a deep hole in a tree. The underside of the tail end is hairless and the skin is marked by grooves and swirls, which make gripping easier. Just like human fingerprints, the pattern of marks is individual to each monkey.
• Less obvious, but equally distinctive, is the Ateles’ lack of a thumb. An opposable thumb is generally seen as a defining characteristic of primates, but in spider monkeys, it is greatly reduced or entirely absent. The fingers are long and thin and the whole hand acts as a hook. The tail more than compensates this loss of dexterity.

It is clear why these primates had been given their name: with their limbs spread, silhouetted against the blue sky, they look incredibly spider-like!