Capuchin Monkeys

By Jack Ewing

They looked like a bunch of teenagers goofing around, teasing each other and just hanging out. Eight of them altogether, most were up in the trees, laying on branches with arms and legs dangling over the sides, or sitting, munching on something, but occasionally one would run to the ground, venture out a few meters from the base of the tree, and quickly scamper back up. None of the monkeys were very large bodied, and from their demeanor I imagined that they were a group of juveniles off by themselves, temporarily separated from the main troop.

Something got their attention. Leisure activity ceased, and all looked in the same direction. After a minute a fat female raccoon with two small offspring in tow came into view, sniffing around and scratching in the leaf litter on the forest floor. The monkeys watched them for a minute, chattered amongst themselves, eventually descended to the ground, gathered at the base of a large strangler fig and again appeared to be in some sort of discussion. They lined up, side by side, standing upright; it appeared to me like they stretched in order to make themselves appear taller. Somewhat hesitantly this wall of primates moved toward the mother raccoon who at first ignored them. At some point the monkeys crossed an invisible line, and the raccoon’s behavior changed from measured disinterest to full attention. Still not alarmed, she checked to make sure that the cubs were behind her, turned to face the line of monkeys, raised up slightly on her haunches, and bared her teeth. I could almost imagine her saying to them: “You want to try it boys? Come right ahead! Who’s first?”

But none stepped forward. The whole gang of monkeys turned tail and ran for the fig tree, colliding at the base, scuffling for position and ascending to the crown. Once safe from the angry mother raccoon they seemed to lose interest in her, like a person trying to forget an embarrassing incident. The monkeys returned to their vagrant behavior. Fat mama continued about her business as if nothing had happened.

Neither I nor any of the Hacienda Barú guides or park guards have witnessed another incident similar to this one. It is a clear example of the incredible variability in the behavior of monkeys and their ability to plan out their actions. Almost certainly, their motive in confronting the raccoons was the remote possibility that they could grab one of the cubs, kill it and eat it.

Capuchin Monkey

The young monkeys described in this occurrence were white-faced capuchins (Cebus capucinus,) the most intelligent of the four species of monkeys found within the Path of the Tapir Biological Corridor and throughout Costa Rica, and the only one that would entertain the idea of abducting an infant raccoon. Although all four species are found in the corridor, only capuchins are common in all parts of it. Mantled howler monkeys (Alouatta palliata), the second most common species, are more numerous south of the Barú River. Scattered troops of Central American spider monkeys (Ateles geoffroyi) populate different parts of the corridor and red-backed squirrel monkeys (Saimiri oerstedii) are seldom seen. Nevertheless, the regeneration of secondary forest and the creation of the Path of the Tapir Biological Corridor PTBC) is having a notably positive effect on both monkey populations and species distribution.

One day in 1997 a lone, male, spider monkey was sighted in a secondary forest near the village of Hatillo. The next day he was observed four kilometers away in the lowland secondary forest of Hacienda Barú National Wildlife Refuge. By the following day he had traveled another three kilometers where he was observed crossing the old gravel road by way of some overhanging branches and moving up into the highland, primary forests of the refuge, the preferred habitat of spider monkeys. This lone male, the first of his kind to be observed at Hacienda Barú in nearly fifty years, was thereafter sighted from time to time deep in the primary forests of the reserve. Prior to 1947, spider, howler and capuchin monkeys were all common at Hacienda Barú and throughout the region. In that year an epidemic of yellow fever killed off all of the howlers and spiders over a large area. Only the white-faced capuchins survived the plague. None of the original settlers in this region can recall having seen red-backed squirrel monkeys, so that species was probably never here.

About six months after the arrival of the lone male spider monkey a single female appeared. For six months they were not seen together. The female traveled with a troop of capuchins and the male was solitary. One of our guests, a British bird watcher, speculated jokingly that perhaps they needed to be properly introduced. But eventually Cupid’s arrows struck them both. They met, became inseparable companions, and in less than a year the pair were sighted with a baby on the mother’s back.

When the baby was about three months old, the three were sighted one morning by Hacienda Barú guide Juan Ramón Segura and some guests who had just spent the night at our jungle campsite. The spider monkey family was traveling through the forest as if on a mission. The adults had no interest in the people, but the young male monkey proceeded to jump around and make threatening gestures. The female came to a small gap between two trees, an easy jump for an adult but a little to far for the infant. She grabbed a branch on the far side of the gap with her tail, spanned the gap with her body and held tightly to a branch on the near side with one of her hands. She looked up at the juvenile and with her free hand make a very human-like gesture signaling him to come. The youngster flagrantly ignored his mother’s request and went back to his threat display. Mama barked something at him and again motioned to him to come. Whatever she barked at the kid got his attention. He immediately stopped the threat display, ran across his mother’s body like a foot bridge, and resumed his threatening behavior on the other side. Again the mother barked something at junior and the three went off into the forest.

By the time the pair had produced three offspring the oldest was close to being reproductively mature, and this brought up a concern about inbreeding. Worried about the need for new blood, I contacted the head biologist for the environmental ministry and told him that Hacienda Barú National Wildlife Refuge would be willing to accept wild spider monkeys if he knew of any that needed to be relocated. As it turned out, this petition was not necessary. A few days later three new monkeys showed up and joined the original pair with their three offspring. The new arrivals temporarily alleviated the worry about inbreeding. As did the first two, the newcomers apparently migrated across the biological corridor from a place called Dos Bocas, and we hoped more would follow. More did follow because in the last couple of years we have had several reliable sightings of more than a dozen spider monkeys in one group.

Two days after the first sighting of three newly arrived spider monkeys, a male, red-backed squirrel monkey appeared on Hacienda Barú National Wildlife Refuge, the first to be sighted here. It was feeding in a strangler fig tree with a group of capuchins and appeared healthy. A few years back a small group of squirrel monkeys had migrated from the south to Rancho La Merced National Wildlife Refuge, near Uvita, but this lone male was the first sighting on this side of the Barú River.

The second most dominant male of a troop of squirrel monkeys will occasionally oust the top male, who thereafter becomes a social outcast and leads a life of solitude. This may very well be the case with Hacienda Barú’s lone male. Nevertheless, there is a great deal of reason to be optimistic. Though this male may never found a troop of squirrel monkeys on Hacienda Barú, he had to get here over the PTBC, and if he made it, and three new spider monkeys made it, all in the same week, we know that the corridor is functioning. We also know that there is a strong possibility that more monkeys may migrate into this region. Perhaps the howlers will be next.

We know that an epidemic of yellow fever eradicated the howler and spider monkeys from a wide area on both sides of the Barú River, but exactly how large an area is not known. The howler monkeys had repopulated the Uvita, Escaleras and Dominicalito area by the early 1970s, but they hadn’t crossed the Barú. In the mid 1990s  I began hearing reports of howler monkeys in the Alfombra area and the Tinamastes ridge, north of the Barú. More recently there have been reports of howlers in the Matapalo,  Dos Bocas and Punto de Mira areas, also north of the Barú River. The only way to tell for sure if the howlers came from the Los Santos Reserve to the north or migrated along the Tinamastes ridge from the south, is to do DNA sampling, and that is not likely to happen. My guess is that they came from both places. The howler monkeys that are found from Matapalo, Dos Bocas and Punto de Mira probably came from Los Santos and the Alfombra howlers came from the south. They have been heard and sighted within five kilometers of Hacienda Barú National Wildlife Refuge, and I am confident that they will migrate here in the next ten years.

To have all four species of monkeys present in this region would make the area much more attractive for tourism of all kinds. What can you do to help insure that the monkeys keep migrating to the area around Dominical? The main thing is to protect and enhance the wildlife corridors. During three decades beginning in 1950 much of the area within the Path of the Tapir Biological Corridor was deforested for farming and ranching. Many forests were fragmented, and many patches of forest were isolated. In the mid 1990s a new forestry law, #7575, went into effect. The new law prohibited deforestation of both primary and secondary forests. In the late 1980s land values began to rise, and many former cattle ranches were sold for tourist and residential development. Since tourists and foreign residents prefer seeing monkeys and toucans rather than cows, much of this land was allowed to regenerate into secondary forests by the new owners. On top of all of this ASANA and other environmental organizations have been encouraging people to conserve the natural habitat wherever it is found. All of these factors combined have caused the area of forest cover in the PTBC to more than double in the last 25 years. In fact, this is one of the few places on the planet where forest cover is increasing. For this reason monkey populations are increasing and monkeys are migrating into areas where they haven’t been seen for years.

If you see or hear howler monkeys north of the Barú River please send me an email at jack@haciendabaru.com The information will help determine their present range.

Filed under: Jack Ewing, Nature and Local History Stories on October 8th, 2010
No Comments »