The first whiff of danger drifted lightly into the nostrils ...
The first whiff of danger drifted lightly into the nostrils of the sleeping furry bundle, penetrating the fog of slumber. A moment later the tree limb where it clung wiggled, triggering it instantly into a full state of alertness. Adrenaline flowed into its veins as it moved quickly toward the relative safety of the flimsy end of the branch. But a perica ligera moving quickly isn't much of a match for a tolomuco. The first of the three sleek, black predators caught the slow moving mammal just before it reached the point where the tree limb tapered sharply.
Twice the size of a large house cat, the tolomuco clung to the thicker part of the branch with its rear claws while it reached out to rake its front claws across the back leg of the perica ligera. One of the tolomuco's companions was on another branch out to one side trying in vain to reach the prey, while the other was almost directly underneath. Pain penetrated its flesh as the perica ligera pulled free, then took another laborious step toward the end of the branch and out of reach of its pursuer. With the next step the thin tip of the branch dropped suddenly and the perica ligera, which was hanging upside down, found itself nearer the tormentor waiting below. But the slow mover knew where it wanted to be, and its only hope of survival was to keep moving.
The lower tolomuco almost lost its balance as it reached upward and took a swipe at the prey's head, catching the lower jaw with a claw. Blood oozed from the gash, but the pain only brought more adrenaline and onward went the perica ligera to the leafy end of the branch. Abruptly it dropped completely past the perch of the predator and the perica ligera reached out, stretching its arm to the limit, and grasped a thin woody vine with both of the long, curved, blunt claws.
The thick nails closed tightly on the vine and the blonde furry bundle released its grip on the branch. Its heart was pounding, but onward it went, knowing without looking that its agile enemies were racing for new positions. Hanging underneath the vine it moved forward foot over hand, hand over foot. Sanctuary was in sight when two swift swipes came unexpectedly. The first opened a deep wound across its face and the second raked its shoulder but didn't penetrate its hairy coat or hide. Another black demon was moving into position on the side. One more foot forward and then a hand and the vine dipped almost straight down. The terrified animal half slid while trying to reach the bottom of the loop where the woody vine curved back up and into the branches of another tree. At last, it breathed heavily grasping the vine with all four feet. Now it could rest, securely out of reach of its pursuers.
The three tolomucos looked down when they heard the human voice. "Look, look, up there! See them? They're tyras. Wait a minute, look out there on the vine, it's sloth. This one is different than the other one we saw this is a two-toed sloth."
A mixture of voices came from the people. "Pedro, look. The sloth is bleeding. What happened? Did those cats hurt it?"
"Those are tyras, not cats," explained the veteran Hacienda Barú guide. "They're like weasels. It looks like they were trying kill the sloth, but it got out on that vine. It can grasp the thin vine but the tyras can't hold on with their claws."
For almost a half hour the group of visitors watched mesmerized as the tyras tried unsuccessfully to reach the sloth. Finally the people moved on, feeling privileged to have witnessed such an amazing spectacle.
People often ask which animals prey on sloths. Their traditional predator was the Harpy's eagle (Harpia harpyja,) now near extinction. When this large raptor was common, it was known to snatch sloths from their arboreal perches. The crested eagle (Morphnus guianensis,) ornate hawk-eagle (Spizaetus ornatus,) and black hawk-eagle (Spizaetus tyrannus) are all known to take opossums and kinkajous, sloth-size mammals, from the canopy, and are certainly capable of killing sloths as well. The white hawk (Leucopternis albicollis) and some of the other large hawks are known to grab baby sloths from their mothers, but would have difficulty with an adult.
Since Pedro's experience proves that tyras (Eira barbara) prey on sloths, it is almost certain that ocelots and margay cats prey on them as well. Additionally, a large boa constrictor could easily kill and swallow a full grown sloth. Nevertheless, none of these predators are a major threat to either the Hoffman's two-toed sloth (Choloepus hoffmanni) known locally as the perica ligera or the brown-throated three-toed sloth (Bradypus variegatus) commonly called the cucula. Attacks are probably infrequent and have little affect on the population.
Both species of sloth are considered threatened and are protected by the Costa Rican Wildlife Protection Law #7317 and are listed in Appendix II and III of the CITES international wildlife protection treaty. Presumably because of their leafy diet, sloth meat is not normally consumed by humans, and therefore hunting isn't a menace. Habitat destruction is the foremost threat to their continued existence. Fortunately, secondary forest cover is increasing in the area around Dominical, as property owners continue to plant trees and allow former pastures to return to their natural forested state. This increases habitat and food supply for sloths, and their numbers here are increasing.
The sloth's slow manner give the impression of laziness, and the word for sloth in many, if not all languages means lazy. According to the book of lists, The Top 10 of Everything, by Russell Ash, sloths sleep about 20 hours per day, placing them second only to the koala in the rankings for the world's laziest animals.
Considering the sloth's reputation for slothfulness, it is rather ironic that they have a record of arriving first. Eight million years ago, when geological forces were forming Central America the first South American mammals to set foot on the isthmus were two species of ground sloth that had to swim over 60 kilometers of treacherous ocean to reach the new land. They won the race five million years ahead of four other species of sloths and later by many other mammals.
At Hacienda Barú National Wildlife Refuge when we started restoring natural forest habitat to land formerly used for crops and pasture, the sloths appeared in these corridors after a few short years, when the new trees were still quite small. A 2001 issue of The Dominical Current had a photo of a sloth in Dominical across the street from San Clemente in an area that was deforested over 50 years ago. That land had been regenerating into secondary growth for less than ten years. Wherever suitable habitat exists the sloths will soon arrive.
Personally, I find sloths enchanting. There is something so special and friendly about them that it is hard to describe. I sometimes guide visitors into the tops of rainforest trees where these charismatic mammals reside, and occasionally find myself in close proximity to them. I call these experiences, "Close Encounters in the Slow Lane." Each is different yet all have a certain magical quality that makes them unforgettable.
In one such experience we first saw the grayish colored animal climbing steadily up a thick, woody vine called a "liana." Dan, Philipa and I were hanging in the crown of a large rainforest tree, about as high off the ground as a twelve story building. We watched the slow-moving mammal off and on as it advanced, lazily but steadily. After ten minutes its path was obvious. Still over ten meters beneath us, it was working its way up through the tangle of vines and branches, clearly heading our way.
Elated by the possibility of a close encounter, we watched intently as it emerged from a mass of foliage and continued upward. The long, powerful claws of the three-toed sloth or cucula became clearly visible as it moved hand over hand up the thick woody stem, carefully grasping and testing each new hold before releasing the previous one.
The sloth neared the large branch of a strangler fig (Ficus spp.,) which was attached to the giant camarón tree (Licania operculipetala,) in which we were suspended. It turned slightly, giving us a view of its back. The long hair and thin black stripe running down the spine indicated that it was a female; males have a swath of short hair there, with a wide black stripe surrounded by brownish-orange hair. We could see a faint greenish tint to her coat as she passed right in front of us, less than three meters away, then briefly disappeared behind the trunk of the fig.
Our next view came when the crown of her head eased over the top of the large fig branch and she stared straight into our eyes, a surprised look on her face. At first she was quite coy, occasionally ducking behind the branch in a slow motion game of peek-a-boo. All of her movements were like molasses in January, even eye blinks. After nearly five minutes of looking us over and, I imagine, considering her alternatives, the young female made her decision. Unhurriedly she pulled herself over the top of the branch and inched her way down the woody vine on our side of the fig.
"Don't let her grab your leg," I whispered to Dan, who was dangling almost directly in her path. Dan shifted slightly, but left his foot on the liana.
No one spoke. We could clearly see the moss clinging to her hair and the flies and beetles moving through it. I felt a strange closeness, an affinity with this charismatic denizen of the rainforest canopy. Any of us could have reached out and touched this beautiful young female as she slowly traversed the three meters from the fig branch to her next obstacle, Dan's foot. I held my breath as she contemplated it for a moment, reached out with her right hand, pushed his foot out of the way with a surprisingly brusque movement, then continued onward. I relaxed but didn't stop watching as she followed the path of the liana down a short distance to where it looped around and back up, bringing her to a point near Philipa. The sloth continued steadily on over to the far side of the tree and the young tender strangler fig leaves that were her objective. After only a couple of mouthfuls she went to sleep, apparently exhausted from her long climb. The whole journey took her 45 minutes, during which she traveled about 50 meters.
Encounters like these are so emotionally intense that the feeling is difficult to describe. I usually find myself in the canopy of Hacienda Barú National Wildlife Refuge a couple of times each week and touching distance from a sloth about three times each year. I never get bored with these episodes. Each time is as exhilarating as the last. I'm thankful that I have the opportunity to know these captivating animals on such an intimate basis. With each encounter, I feel a little closer to them. Sometimes I recognize sloths as individuals, and it seems like I'm meeting an old friend. Regardless each close encounter in the slow lane is magical and something to be treasured.
|
