I was trying to get to an untouched beach through the mountains. While driving up a narrow passage of a washed out mountain path I was shocked to see something walking in the distance under the tree line. I had just turned around as the road became absolutely impassible for anything less than a 4x4 designed for specifically for extreme conditions... and definitely too much for my Jeep.
Was that a monkey? Are they Puerto Rican Monkeys?
As I caught a glimpse of one of them from the back, moving away from me, I thought: "Was that a Kangaroo?". The strange long legs and stride, from the back, looked a lot like a marsupial.
I had my camera in the back. I jumped out to get it. I wanted photographic evidence of this whether is was some species of monkey not supposed to be in Puerto Rico, or the Chupacabra itself! 
I shut down the engine and waited to see if they might double back. After about 10 minutes, I figured I had startled them and decided to leave. Just as I went to turn the key I saw a parade of brown legs moving under the tree line. It was a pack of monkeys!
Monkeys in Puerto Rico? They are not supposed to be here, and they certainly are not native. They kept their distance, I did the best I could with a low end digital camera to get a few shots from a distance. Of course, I did my research when I returned home. And interesting findings in deed. These monkeys are the wild descendants of escaped research monkeys. If they are, in fact, Rhesus monkeys they may also be infected with a strain of the herpes virus which could be fatal to humans.
Puerto Rico’s population of wild monkeys was brought for research purposes in the 1930s. Several hundred were released on a tiny island in the Boqueron Commonwealth Forest, about a quarter-mile from Puerto Rico’s southeast shore. Sightings of wild monkeys were first reported in the 1970s.
My research seems to indicate the pack of more than a dozen monkeys, most of them juveniles, were either Patas or Rhesus monkeys. These are the kinds commonly used in research, and were among those noted as having escaped from research facilities in Puerto Rico. More than 1,000 are said to be living exiled on "Monkey Island", a 37 acre island just off shore of Puerto Rico. They are studied by Primatologists and presumably still extracted for research purposes when necessary. As it turns out, the West Coast of Puerto Rico has a monkey issue. They are extremely fertile, and are happily inhabiting the higher altitude regions of the island, giving them lots of territory to dominate.
After getting a look at a few of these guys, it's not so hard to imagine where the legend of Chupacabra came from. Remember, monkeys are not native to Puerto Rico. Running into these guys at night in your backyard, or chowing down on a chicken might be enough to start an legend. Note: Rhesus monkeys are said to sometimes eat small animals. Interestingly enough, these monkeys may be adapting very well.
A group moved to a Sanctuary in Florida escaped after swimming through the water surrounding their enclosing island. Apparently they are not supposed to like water. If that sounds interesting, you might want to check out my blog entry on "The Island Effect: Morphologically Accelerated Evolution on Islands". These guys might be improving their swimming abilities and developing a keener interest in pollo (chicken). They do share many of the characteristics of some Chupacabra eye witness descriptions.
If you want to see the wild monkeys, you will find them in the Mountains of Cabo Rojo. Beware. If you force a close encounter, a scratch or bite could be very bad for your health.
The Insider
See also:
Wild Monkey Plague in Puerto Rico
Thousands of Monkeys Used for AIDs Testing on 37-Acre Island Called "Monkey Island" Off Puerto Rico
Puerto Rican Wild Monkeys Moved To Florida Santuary Escape by Swimming Through the Moat
