El Valle Open Air Market

At first glance we could tell that enough rain had not fallen to cause a flood bad enough to scour the channel, wash away our expensive equipment, and scour the channel badly enough to ruin our experiment. Several large yellow and black frogs jumped on the stream banks; the golden frog of Panama was doing well here for now. They were not concerned about our presence. We walked another quarter mile up the slippery muddy trail to where the pump was dripping in the tracer solution at a constant rate. We changed the battery and added fresh tracer solution. It was good to get the weight of the tracer solution out of our packs. Tadpoles were swarming in the stream as they had been the day before, the slightly increased flow and cloudy water from the rain was not bothering them apparently.

Everything looked in order so we ate lunch and headed back. By the time we started back the rain had cleared and the tropical sun had started to beat down. It heated up quickly and the road was steep from Rio Maria up to the volcano rim, to where it would drop back down into the crater and wind down to El Valle. We started regretting that we had not thought to bring more drinking water. We slid our way down over the slippery clay on the steep hill that had stopped the trucks in the morning. Our ride had not arrived at the bottom of the hill, so we started down the road toward the hotel. We hoped we would not have to walk the entire 5 additional miles back without a lift. After a bit we reached the area where there were farms and passed a place where a citrus tree had dropped its fruit into the road. These green fruits were not quite grapefruits and not quite oranges. Nonetheless they were a welcome and delicious source of liquid as we made our way toward El Valle. Another half mile down the road one of our trucks pulled up and we rode back.

That afternoon it was still sunny and we made our way down to the open market in El Valle. It is a mixed tourist and local market with booths selling everything you would need to live in the area, as well as many trinkets, locally produced and imported art objects aimed at tourists. While some may consider a department store a modern invention, the city market has a comparable array of goods crammed into the same amount of space; many more merchants participate in selling goods. We bought more food and some gifts for our families. I noticed fruits not common in the US (custard apples, nance) as well as those that are (pineapple, oranges, and grapefruits). The produce was fresh and much better than commonly found in large supermarket chains.

Items mainly for tourists included the well known traditional molas, an appliqué tapestry made by Kuna Indians and transported from the Caribbean coast to the north. Tagua nuts are about the size of a lemon with an ivory colored interior that hardens after being carved and exposed to air. The tree in native from the Southeast of Panama into Northern South America. Before plastic buttons, the nut was commonly used to make buttons that looked like ivory. Using these nuts to produce statuettes is an environmentally responsible solution for those who like ivory carvings. Commonly, intricate animals are carved in the tagua nuts and the carving is painted.

Natural animals are a common motif in these artisan-produced objects and most are fairly realistic. Many of the Tagua nut animals are extremely accurate representations, both in terms of color and proportion (although there are some inferior products to be found as with any craft that is sold for tourist consumption). These crafts suggest that the Panamanian artists, at least, value their wildlife. If they were only carved for tourists, attention to details of form and coloration of local spiders, frogs, and snakes would be unnecessary, as most tourists have no idea what the real animals look like. There are also cocobolo carvings of animals, and palm-fiber baskets and purses.

I was particularly interested in how many golden frog statuettes were available, some were tagua carvings, but most of the frogs were cheap plastic versions. The golden frog in Panama is the equivalent of the bald eagle in the US. The population crash of the bald eagle ultimately led to banning use of DDT in the US because people were upset the national bird could be lost. The toxin DDT concentrated in their eggs and made them so thin they would crack. The US people found this unacceptable and refused to allow use of DDT.

The Panamanians are experiencing the demise of a cultural touchstone to their country, and they can do little to stop it, as will be discussed in the next chapter. I also wondered if the statuettes would still be available in a few decades and how much they would look like the actual frogs. Many of those available in the market that day were true to the morphology and coloring of the golden frog. Others were depicted smoking and drinking martinis, kitschy tourist bait. Cultural evolution and no real comparison alive in the wild could ultimately lead to only a stylized version being sold, if any.

We watched as tourists disembarked from large air conditioned busses and flooded into the market only to leave an hour later. Overweight tourists haggled with the market vendors; many had cameras with lenses over a foot long or expensive digital video cameras. It was a typical scene in a tourist town. The atmosphere was definitely more relaxed after the last bus left. It was humorous that I too was a tourist, yet somehow felt superior to these bus tour participants.

That evening, after dinner I noticed that a television in the bar across the street was playing the super bowl. Passing up this bit of “culture” from home proved too difficult and we decided to go in. Entering the bar I noticed the gangs of tough looking youths hanging around outside. There were very few women in the loud and crowded bar; obviously the few females there were attending in a professional capacity. These professionals were not the women young men would bring home to meet their mothers. In general, this was one of the rougher bars I had been in. Feeling a bit insecure, I stayed near the bar with my group and watched the game.

Suddenly it struck me… nobody was smoking. I asked about this and was told that smoking had been outlawed inside public buildings in Panama a year before. Here I was in a rougher bar than any in my small town in the Midwestern US, yet smoking was not allowed here while such a ban in my home town occurred 2 years later. Some places in Panama are more socially progressive than parts of the US. This observation led me to realize that relationships between society and health were more complex than I had considered.

Later, I discussed the idea of social responsibility for health and environment with Heidi. She has an interesting perspective having lived in Panama for the last half decade, but growing up in the US. She mentioned that the Panamanians were also very concerned about global warming and most were unhappy with the way the US has been dealing with this issue. They felt that the US was burdening them with environmental problems associated with global warming without spreading the benefits of their extravagant lifestyles to the Panamanians. Essentially they felt the US people were burning the fossil fuels and they were paying the price for our consumption.

I don’t remember who won the football game. I do remember that the next morning I got my luggage! We had another working pump and I had some clean clothes. The clothing I missed most, other than clean underwear, was the quick dry pants. Quick dry clothing in the tropics is far superior to denim jeans. The thin synthetic fabric protects you from insects and the sun, but is not too hot. Given the amount of rain in a rainforest, the quick dry feature is advantageous. Plus, my quick dry pants looked a good bit nicer than the droopy jeans I had been wearing non-stop for the last 5 days.

Bannanas, filtering and lost luggage.

Working in the dark is difficult at best and potentially dangerous in the jungle. The road back would be even more treacherous in the dark than the nighttime jungle, so we finished up in time to get our gear back into the trucks and drive back to the hotel before dark. Edgardo called about my luggage when we returned, but it had not yet been found. Back at home my wife had been working on tracking down my luggage, and she had made no progress either. At this point we also received word that a member of our planned research group, Karen Lips, had also lost her luggage and was staying in Panama City to attempt to retrieve it.

One last member of our research team, Cathy Pringle, had arrived at our hotel that afternoon after coming in on a different flight. She is an internationally respected researcher, a professor at the University of Georgia and has been more involved in advancing the study of tropical streams than almost any other researcher in the world. She has worked across the Caribbean, in Costa Rica, Panama, the South Pacific and Madagascar.

If somebody in the research community mentions “tropical stream ecologist”, Cathy is who comes to mind. She is an innovative person who knows how to get the resources she needs to do the research. Her brash and gregarious nature and deep desire to understand and preserve tropical streams have taken her to parts of the world that few have experienced. These qualities make her an extraordinarily interesting person to work with. She is an original and hard working researcher. I had worked with her for years on issues related to our stream ecology society. Among other things, Cathy loves little tasty tropical bananas and shopping. She has a twinkle in her eye and a mischievous nature, as well as a reputation for leaving pairs of dirty socks behind everywhere she travels. She also is the exception to the rule about not wearing sandals while working in the jungle.

Speaking of dirty clothes, mine were becoming a bit dodgy; I washed out what could be washed and we headed into town for dinner. After dinner we broke out a little rum, mixed it into some pina-guava juice, and got down to doing our chemical assays. Some of the local help thought the party would be fun but when they realized we were actually doing lab work and calculations for our experiment the next day, they drifted off to their own rooms. After a late night of planning, we turned in, thinking about our getting going early the next morning.

I pulled on my sodden clothing the next morning, followed by the usual fruit and cereal breakfast, and of course, my diet coke. The coffee drinkers were enthusiastic about the fantastic Central American coffee, and I almost regretted not having taken up the habit, the smell at least was quite pleasant. After repeated runs through our equipment lists, and a longer delay than we planned to discuss the experiment (more questions, it turns out Cathy, as well as Piet, is really big on questions), the group piled into the trucks and we started back to the field site. Matt had mentioned to me before we left the States how the steep rocky roads started to wear on you after a week, I was starting to understand what he meant, and this was only the second day of driving stiff-suspension 4 wheel drive trucks bouncing up and down the hills.

We got to Rio Maria without major problems and carried our gear to the upstream point of the nitrogen tracer experiment. We needed to pump trace nitrogen into the river continuously for a week, and that required us to carry 5 gallon carboys full of the chemical that we had dissolved in water the night before, a half mile up the stream. Five gallons is over 40 pounds. The jungle trail was always slippery, and the added weight of the carboys did not help. Our footwear was knee-high rubber boots which do not have the best traction. This was hard work, and we were grateful we made it before the heat of the sun peaked.
There were more samples to collect, so we had another full day of work ahead of us. The samples were taken and the tracer experiment started as planned. We had some down time between measurements and this time was used to crack open tins of food and crackers for lunch. I had brought my underwater camera and started to take pictures of the tadpoles in their native habitat.

Underwater cameras have recently become fairly inexpensive and easy to use with the advent of digital technology. They are a fantastic piece of equipment to have, even if underwater pictures are not desired; the jungle is always humid and drippy and the protection is helpful. I had spoken to professional photographers about using cameras in the tropics and they mentioned that fungus and moisture always work their way into lens systems and eventually fog them. At least the underwater cameras are protected from this and the desiccant packs placed in them help even more.

Also in down time, water samples needed to be filtered. We had only manual vacuum pumps and needed to filter large amounts of water to collect particle suspended in the water onto filters so they could be analyzed, and the filtered water also needed to be saved for analysis. The pumps kept breaking down; unfortunately my hand pump was still in my lost luggage. Emergency repairs with duct tape and epoxy were all that allowed us to keep using these pumps. Cathy Pringle is one of the few full professors I know that really enjoys sitting in the sun next to a tropical stream, eating the occasional small sweet tropical banana, and pumping water samples for hours. This is probably a good release from the hectic pace she maintains back in the states at the University running her large laboratory. We willingly allowed her be the official jolly field filterer.

As 6:00 pm approached (sunrise and sunset time are certainly predictable in the tropics) we had packed our gear and put some brush over the trail to obscure our path up Rio Maria. We knew that the thousands of dollars of gear we had up the stream would be worth nothing to the locals, but could not be certain that the gear would still be there the next day if we advertised the location where we were working. Making our way up the road carved into the wall of the extinct volcano, the setting sun illuminated the jungle draped rock pinnacle a few miles away, a breathtaking end to a good day in the field. All that was left was dinner, drinks, and more filtering and analyzing samples that evening. We also started entering data into our computers and making certain that the field notes were all organized with their data duplicated against loss.

The good news when we got back was that my luggage had been found and delivered to the bus station. The bad news was that it was Saturday night and the station was closed on Sunday. Try as we might we could not get the employees of the bus company to come in and open the station. I offered bribes, but they were worried that violating regulations would cause them to lose their jobs. My bribes were not big enough. Of course Edgardo was patiently mediating all this; I purchased minutes for his cell phone to reimburse him for all the calls he graciously made in pursuit of my luggage. The restaurant we ate at was right across the street from the bus station, so we went to look for my bag. Sure enough I could see my suitcase sitting there. My filthy jeans seemed a bit worse for the wear and did not smell pleasant. My trip mates would probably say they stunk. My suitcase sitting a few feet away, yet unattainable, did not help things much in my mind.

The next morning it was raining. Our experiment was taking place during the “dry” season, but we were in a rainforest. The rain made us very nervous because we needed to be certain that Rio Maria was not flooding and ruining our equipment and also we needed to carry fresh tracer solution and check that the pump delivering the solution to the stream had adequate power and was working properly. The clay parts of the road to Rio Maria were very slick from the rain.

Scheduling issues related to the rain caused tensions to rise that morning. Also, some of the crew was uncomfortable with the fact that all of the drivers were not experienced with four-wheel drive and manual transmissions. All our four-wheel drive trucks were manual, and driving them on the treacherous mountain roads was not a task for beginners. We got all the passengers sorted out and started up the road in four wheel drive (we usually did not lock in the hubs for the four wheeling until we got to the really steep bits but we needed it as soon as we left the pavement this day). When we reached the steep part, everyone but the drivers got out. Edgardo then tried to drive up the hill. It was a disaster. He would spin all four wheels up about quarter way and then get stuck, only to slide backward down the hill. Considering the steep drop-off on one side of the road, sliding in the mud backwards was not exactly safe. We were lucky none of the trucks, or for that matter, the people, were damaged.

Alex, Bob and I decided we needed to walk in to check the experiment. We packed up some tracer solution, batteries, sampling equipment, lunch, and put on our rain gear. A time was set for a truck to come back and pick us up. Getting up the steep bit was difficult, even on foot. The only good footing available on the greasy road was protruding rocks or vegetation growing along the edges. We slipped our way up that hill, and the next, and the next, to the top. Then we started on the road as it traversed down the outside of the ancient volcanic crater.

Every once in a while Alex would point out something interesting that I had never seen before. The guy is a fanatic for leaf-cutter ants and insects of all kinds. He has a fantastic eye for biodiversity, and by the end of the trip I realized that he is one of the best natural historians I had ever been in the field with. I have been in the field with quite a few well trained, expert biologists. We could hear birds and frogs calling in the jungle, but the thick mist obscured most of their locations. The frogs were calling even more vigorously than the day before, if that was possible, because the rain stimulated them. A couple miles later we were at Rio Maria.

Danger in the jungle

The rainforest around Rio Maria is not pristine. The area was logged 50 years or more ago. Large birds that once flew above the trees, such as the Scarlet Macaw, are gone, most likely captured by locals. No howler or spider monkeys are left in this jungle, and the collared peccary (javelina) is not found as it once was. These mammals were probably taken for food or the pet trade by people. This region is not protected and is too close to human habitation for most large animals to survive collection or hunting. Still, the small plants and animals are very diverse and the jungle here has much to offer to biophilic (biology loving) visitors.

The ability of the jungle to rebound from logging is a direct consequence of the millennia that these trees and associated plants have interacted with humans. Panama has been inhabited for at least 11,000 years. The indigenous people have a sophisticated culture, that among other things, developed unique and ornate styles of pottery. In this region, called Coclé, the indigenous culture required rotating agriculture which would have been slash and burn. The jungle in the flat parts around Rio Maria has very likely, over thousands of years, been repeatedly been cut (slashed), burned, cropped and after a few years left to return to jungle to recover its fertility.

While the jungle around Rio Maria was missing some components of an extensive, old-growth, tropical rain forest, it still had incredible diversity and beauty. Only in recent history have humans developed the machines and population densities to completely remove jungle from tremendously large areas. There is little hope the diversity will return to the areas of massive deforestation as it does to the small patches that are cleared for a few years by native agriculturists under slash and burn cultivation. We know that very plant and animal diversity could coexist with the traditional native practices, but those days are now gone.

Working in the forest requires caution. Those who work in the jungle say that falling trees and limbs are the greatest danger. If you are unlucky, one will fall and hit you in the head. If you spend much time in the jungle you will hear limbs falling, and the trees in even this re-grown rain forest can be a couple of hundred feet high, so the branches can gain considerable momentum before they strike an unlucky researcher below. Each tree limb plays host to numerous epiphytes. These epiphytes include the orchids and a number of what we commonly see as houseplants in homes in developed countries of temperate climates (for example ferns, spider plants). These plants take advantage of the limbs of the trees to grow higher in the canopy where they can get far more light than they could on the forest floor. The mass of plants on each branch grows to a greater and greater mass. Eventually the weight is too much for some branches to bear and they come crashing down.

The large trees tend to have shallow root systems that are spread across the jungle floor to intercept nutrients that reach the soil there. Tropical jungles generally have very poor soil and organic materials containing nutrients are rapidly degraded and the nutrients they contain scavenged quickly. This is part of the reason for slash and burn agriculture; the vegetation that is cut down and burned provides nutrients for a few years, but the soil is not productive so the fields are abandoned after a few years. Unfortunately, if cropping continues the soil becomes so
unproductive that not even the jungle can return.

The shallow roots are not good at holding up the trees, and this is made up for by the buttresses (broad supportive ribs) that extend away from the base of the trunks. Even with the buttresses, a large tree will fall occasionally. Because it is connected to others by dense vines, not only will it smash the trees directly where it falls, but also the falling trunk will take many smaller trees down with it.

Tarzan movies are not very realistic, but there really are vines that could support a large primate that crisscross the jungle canopy. We tested this as college students in the jungle finding vines on hills that would allow us to swing high into the air.

When a large tree falls and takes others down with it, the light gap that enters the forest will allow new rapidly growing trees to grow up into the canopy. This process is part of what leads to the tremendous tree diversity in the tropics; the light gaps promote species that would not be able to compete in the dense closed canopy of the jungle.

A newly fallen tree also attracts local people scouring the forest for exotic orchids that might have been growing high in the canopy before the tree fell. These plants can bring a hefty price. The orchids are for sale in the local markets and collectors around the world support a legal and illegal orchid trade.

There are other dangers; toxins are common. Some palm trees commonly found near the ground on of the jungle have large poisonous spikes that will cause a nasty allergic response in the impaled hand unlucky enough to grab a trunk to avoid a fall. Large garishly colored caterpillars have poisonous spines. While these caterpillars are not aggressive, inadvertently brushing against one is not advised.

Paraponera ants that crawl on tree trunks are also called bullet ants because a bite from this inch-long ant feels like a bullet and causes pain for 24 hours. Their large mandibles cause what is said to be the most painful insect sting of all; the pain results from a potent neurotoxin. Initiation rights of some indigenous South American people entail repeated bites from these ants. It is difficult to imagine being stung 20 times without screaming, but this is what is reportedly what it takes to be a man in some cultures.

Poisonous snakes are also a concern, but are less common at higher elevations. It is possible that the bushmaster, Lachesis sp., the largest (up to 14 feet long) of the pit vipers, could be encountered up to 4000 feet elevation. The Fer-de-Lance, Bothrops asper, can be found on the ground or juveniles can be found in trees. Tree vipers also known as eyelash vipers, (two species at high elevations), hang from trees. Hog nosed vipers, tropical rattle snakes, and coral snakes all can be found in Panama. All these species are poisonous and bites from some can be fatal. It is always best to watch where you are stepping and move with care when walking in the jungle. This is not sandal country (but the next day we would see the exception) and boots, not flip flops, are advised. The dry season we were in, is also the time when the bushmasters are most likely to bask near Rio Maria, so we were particularly careful to watch for these vipers.

Of course, insect-borne diseases are also a concern, as they are in much of the tropics. Diseases found in Panama include malaria, chagas disease, dengue fever, yellow fever, and leishmaniesis. We killed an Assassin Bug in our hotel room, known to be a vector of chagas disease that can be fatal if left untreated. The usual precautions against insect bites and appropriate vaccinations at least decrease the worry. If you see an Assassin Bug in your room in Central America, kill it. These issues are not enough to keep many scientists and ecotourists away. The fabulous diversity and unique area are so attractive, and appropriate precautions minimize the chances of danger .

Leafcutter ants

Near the upper edge of our research area, Alex pointed out an opening in the forest canopy above and the sunlight actually made it to the forest floor here where it shone on a massive dirt hill. The hill and the opening in the canopy were the work of leaf cutter ants; they had stripped the trees of their leaves above their huge colony. These ants forage into the vegetation, cutting off bits of leaves and bringing them back to their nests. It is said that the ants can defoliate a small tree in a single day. A web of ant trails spread out into the forest, each trail swarming with a line of ants coming or going. Some trials went up the trunks of the massive trees near the colony.

Large soldiers ran along the trials guarding the more numerous workers. Worker ants were carrying pieces of leaves as large as their own bodies. From a distance these trails looked like small streams of green leaves moving along toward the colony. The worker ants ran along the trails back inside the nest, left the leaves, and then scurried back the other way for more. The soldiers were always patrolling for predators that might eat the workers, including ants from other colonies.
Some smaller ants seemed to be hitching a ride on the backs of the ants that carry the leaves. My first thought is that these were the lazy ants. It turns out these are small soldiers that are the first line of defense against attack. They run along the trial unassisted but they also apparently ride on the back of the workers to fight off parasitic flies that try to lay their eggs on the ants’ heads.

Leafcutter ants cannot get nutrition from eating the leaves themselves, and tend gardens of fungi that grow upon the leaves taken into the chambers within the ant hill. Deep in the colony there is an even smaller bodied ant that tends rooms where the leaves are inoculated with the desired fungal food. The smallest bodied ants tend the fungi on the leaves, tend the larvae and attend to the queen.

The rooms below the jungle floor are the optimal humidity and temperature for the fungus. The ants weed other kinds of fungus and bacteria out and eat their preferred crop of fungus from their dark gardens. The ants also have bacteria in special glands that excrete antibiotics that keep the food fungi from being overgrown. Species of leaves that do not allow the proper fungi to grow are removed, and somehow the workers are signaled not to collect that species any more. If leaves that are growing the desired fungi are removed from the colony, the species of fungus that the ants like to eat is quickly overgrown by others. When a winged queen leaves to mate and start a new colony, she takes a bit if the fungus with her to start the new colony. The fungus would not compete without the ants, and the ants could not survive without the fungus, yet another example of coevolution.

The ants continually replenish their gardens with fresh leaf clippings for the fungi and remove the waste to the outside of the colony. The large dirt hill is made up of soil particles from the excavation of the colony and waste from the colony. Humans are not the only species that has had an “agricultural revolution”. When jungles are cut down the hills remain and can be a hazard for livestock. When cattle walk over the once active ant hill, it can collapse into the large area of caverns excavated below and a cow can become trapped. The ants damage crops and their colonies can damage roads.

These ants are common in the tropics and there are 41 species from two genera of ants, and they tend any of several species of fungi. Termites and ambrosia beetles are the only other insects known to tend fungi. This species is a fascinating result of evolution of social insects, with the adaptation to use fungi, the bacteria that helps maintain the fungi, and the six morphologies of ants all in the same species inhabiting the same colony (the smallest workers inside the nest, the slightly larger soldiers outside the nest, the still larger workers that collect the leaves, the largest soldiers, the queen, and during certain times males).

One enemy of the leaf cutters is the army ants that patrol the forest. These ants are predators that move in a continuous stream across the jungle floor. If you follow the trail of the army ants you will eventually come upon their nest. It is a bivouac that is a ball of ants as big as a watermelon suspended a few feet above the jungle floor. The queen is inside this seething ball of ants. The ants control the interior temperature of the ball by the rate they cycle to the inside. Follow the trail that leads from this ball of ants a mile or two through the jungle, and you will find the next bivouac with the next queen. These ants move through the forest, occasionally in swarms. The ants kill every insect that cannot escape and will even take smaller animals. Birds follow these army ants to snatch the insects the ants scare up.

It is fascinating to follow a trail of these ants. Where they come to a place that is difficult to cross, the ants grasp the one in front of them and make a chain of ants. Several of these chains side by side make a bridge for the remainder of the ants to cross over. If leaf cutter ants are the farmers, these are the raiders. Army ants are aptly named. They will overcome any other insect colony they encounter, or any animal that cannot get out of the way, regardless of size.