Steemians, today I present a most special primate.....

The Spider Monkey

Monkeys vs Apes

First off I want to clarify terminology when speaking about primates. More specifically I want to distinguish the difference between an ape and a monkey. A monkey has a tail that they often use as balance and support. On the other hand, an ape such as a Gorilla or Chimpanzee does not have a tail. Often when I have been talking about primates people very quickly think that all primates are monkeys, but this is not true. Next time some one calls an ape a monkey you know better! :)

Tell me about Spider Monkeys

The most striking feature of the Spider monkey is the fact that they are not a 4 limbed primate - they are a 5 limbed primate! They have a prehensile tail that acts as a 5th limb! A prehensile tail means that they are able to grab any object in their environment using their tail. If you look carefully at the photo above you can see that the tail does not have fur underneath as it is adapted to provide a good grip! Spider monkeys start using these tails very early in life - usually a couple weeks into new life! Reproduction is common only every 2-3 years. They are also known to have only 4 fingers and no opposable thumb unlike Gorilla's, for example.

Spider monkeys are found in Central and South America. They are omnivores and spend most of the time high up in the canopy of the rainforest. They weigh about 13 pounds and are 14-26 inches in size with a life span of about 22-27 years.

They tend to be gregarious and are found in social group of 3 to several dozen. They are diurnal being most active in the early morning. Their key role is seed dispersal in the rainforest, therefore they are an essential species for forest propagation.

Personal Encounter

In 2008 I embarked on a research program in the Costa Rican Jungle. I was enamored by primates and was doing a degree in psychology. In my country the only primates available for observational research were captive. I was disappointed and wanted to go back to the jungle and be in the wild again. So I decided to sign up for a research course that included primate behavior and conservation with one of the foremost primatologists of our time! My project was focusing on laterality - did capuchin monkeys (Cebinae) show laterality (left or right handedness) or were they ambidextrous.

The capuchins were indeed something special! Every morning before sunrise we started our journey into the jungle. Our torches flitting from side to side, keeping an ear and eye for the sounds of upper canopy movement. The capuchins would jump from tree to tree until they arrived on the property and gorged themselves on fruit. The first few days we were in their area they were not amused. They would see us and run for neighboring trees only to see us beneath them again. They made for hard to find areas by making us run through streams, swamps, ferns and thick jungle but we stuck with them (we had to - we needed to collect data!). It was grueling and to top it off they would throw seeds, bark and other objects they could find to snuff us off their trail. Eventually they realized we were not to going to go away and meant no harm. They agreed to let us stay!

One day I remember washing my clothes by hand at the camp. It was luxurious actually - we had cold showers! It had stopped raining for once. The sun was starting to shine through the foliage and I was glad for the down time after being up before dawn to follow the rambunctious capuchin monkeys. I was so enjoying the peace and quiet - I was by myself. It is interesting how mundane things can become so meditative when you are away from the expectations of the civilized world. Suddenly, I heard a rustle in branches behind me. There they were a family of Spider monkeys (Ateles) watching me. The observer now the observed! There were three of them. A male, female and infant tucked under mamma's belly. There must have been more but I couldn't see them or hear them. What was unusual is they usually stayed up higher in the canopies. With the blink of an eye were on their way - amazingly nimble as they used their long arms and prehensile tail to swiftly move through the canopy. Each movement taking them further and further away from sight until all I could do was listen to the sound of the rustling branches! I had always been so intrigued by them. So large and yet so slender moving in silence but for the trees that gave their presence away. I always got the sense that there was a gentleness about these primates.

At the end of my research I did find that capuchins were ambidextrous - they did not have a preference for right or left handedness and therefore did not show laterality. I needed more time but it was fun brachiating around with these primates for a few weeks!

Spider monkeys have recently been listed as critically endangered as they are losing habitat and being hunted as food.

Pura Vida!

Check out the video by National Geographic about Spider Monkeys!

References
http://www.nationalgeographic.com/animals/mammals/group/spider-monkeys/
https://www.macalester.edu/~montgomery/spidermonkey.html
http://www.srl.caltech.edu/personnel/krubal/rainforest/Edit560s6/www/animals/spidermonkeypage.html
http://www.costaricajourneys.com/spider-monkey/