Biodiversity Firsthand

by Jack W. Sites, Jr., professor of zoology, BYU

Introduction

Biodiversity—a relatively new word in the English language that is unfamiliar to most—is simply a contraction of biological diversity that all of us encounter personally on a daily basis. Whenever we eat a meal, make any kind of purchase, work in the garden, or take a vacation, we derive direct and indirect benefit from biodiversity. Simply defined, biodiversity is the grand total of the profusion of all life forms on earth (plants, animals, and microorganisms). When we think of life, we immediately conjure up images of familiar plant and animal species.

Scientifically, biodiversity is more precisely defined by three components. The first of these is a genetic component that specifies the different combinations of genes in all individuals that comprise any species. Groups of individuals sharing the same habitat in nature usually share the same local adaptations to that habitat, and are often recognized as discrete races or varieties that differ regionally from other populations of the same species, but all comprise the total genetic diversity of the species.

Second, the species component itself defines groups of individuals that breed predominantly with one other, but not with other groups. One of the great scientific mysteries of modern biology is determining how many living species inhabit the earth. The latest official count is just over 1.8 million, but educated guesses take the total number from 10 to100 million.

Finally, biodiversity is defined by an ecosystem component that refers to specific regions of land or water that can be defined by their physical structure, predominant climate, and the interacting species that comprise their living communities. It will be obvious to most people that a desert is a very different ecosystem than a forest, but perhaps less obvious is there are many different kinds of deserts. There are a minimum of four in the United States alone and distinct subdivisions within each of these. The different kinds of environments found across the earth’s surface, combined with the uncounted myriad of living species adapted to live in each, generate an enormous diversity of ecosystems.

Collectively, these three components of biodiversity are responsible for the productivity of the earth and provide humanity with uncountable, and usually undervalued, benefits. Because it is the ultimate source of new foods, medicines, and a host of other products, biodiversity can be thought of as living wealth—humanity’s genetic savings account.

Amazonia—the name itself conjures up mythological images of deadly diseases, stifling heat, giant snakes, schools of man-eating fish, stinging plants, and biting insects—in reality contains but a tiny fraction of these things (the danger of which is vastly over-blown in all cases). It offers students of the life sciences a living laboratory unparalleled by any other landscape on earth.

Much of this allure stems from the immensity of the region, and the innumerable species it contains. In size, the original expanse of Amazonia was about six million square kilometers (almost the size of Australia), and, while some regions have been completely cleared of forest or heavily disturbed, probably 75 percent of the Amazon forest remains relatively intact. It is by far the largest single block of rainforest on earth, and it is drained by a river system through which one-fifth of all earth’s freshwater flows. The main channel of the Amazon River itself carries twelve times the volume of our Mississippi River, opens to the Atlantic Ocean at a mouth wider than the distance from London to Paris, and contains in its mouth an island the size of Switzerland. The sheer immensity of the region, and the remoteness of much of this forest, makes comprehension difficult.

I can do no better than the Brazilian geographer Euclides da Cunha, who penned these sentiments:

It is entirely impossible in the Amazon to take stock of the vastness, which can be measured only in fragments; of the expansiveness of space, which must be diminished to be appraised; of the grandeur which allows itself to be seen only by making itself tiny, through microscopes; and of the infinity which is meted out little by little, slowly, indefinitely, excruciatingly. The land is still mysterious. Its space is like Milton’s: it hides from itself. Its amplitude cancels itself out, melts away as it sinks on every side, bound to the inexorable geometry of the earth’s curvature or deluding curious onlookers with the treacherous uniformity of its immutable appearance. Human intelligence cannot bear the brunt of this portentous reality at one swoop. The mind will have to grow with it, adapting to it, in order to master it. To see it, men must give up the idea of stripping off its veils (Um Paraiso Perdido [A Paradise Lost], 1906).

Descriptors such as “the world’s greatest forest” and “Genesis unfinished” have been used to portray the vastness that so impressed da Cunha. In 1999, as a result of previous research in Brazil, I was invited to organize a Tropical Biology field course to convey some of the Amazon’s mysteries to students. For me this was an opportunity not to be missed.

The Trip

The original invitation was issued in 1999 by Vitor H. Cantarelli, director of the Centro Nacional dos Quelônios da Amazônia (CENAQUA or National Center for Amazonian Turtles), an agency within the larger Instituto Brasileiro do Meio Ambiente (IBAMA or Brazilian Institute for the Natural Environment; equivalent to the U.S. Department of Interior). Cantarelli suggested that if several biologists could organize a field course in tropical biology that integrated lectures and field work, for a duration of perhaps eight to ten days, then he could pull staff from other field stations in the reserve to assist with support of perhaps twelve students. He envisioned a mix of students representing BYU and several Brazilian institutions, with enough bilingual students to translate all lectures in both directions as needed.

I returned to BYU after the 1999 trip, and quickly recruited Professors Mark Belk and Riley Nelson to participate with me in developing such a course— with generous support from the Roger and Victoria Sant Educational Endowment for Sustainable Development in the College of Biology and Agriculture, and the Department of Zoology. The three of us were required to submit outlines of the subject matter that each of us would present, and Cantarelli then integrated our outlines into a document for presentation to his superiors within IBAMA.

We also signed on Malinda Wallentine and David Gonzales—BYU undergraduate students both chosen for their academic records, interests in conservation biology, and previous research experiences—to join us in Brazil during the 2000 fall semester.

The project was approved by IBAMA, and Cantarelli was able to secure travel funds from a private source (a bauxite mining company with leases just south of the reserve) to support travel for twelve Brazilians. This number included nine undergraduate students from six Brazilian institutions, and CENAQUA employees (including Cantarelli). When combined with the two BYU students, our class totaled fourteen students. One additional student, an MS candidate in Zoology from the University of São Paulo, had been at the Rebio Trombetas station for three months doing field research for her thesis work, and she joined some of our group’s activities as time permitted.

We departed 27 October 2000 and, after thirty-plus hours of travel, including a five hour boat trip up the Rio Trombetas, reached the Reserva Biológica do Rio Trombetas (Rebio Trombetas hereafter) in the state of Pará, in eastern Brazil. I had been invited to organize a field course here due to the outstanding educational opportunities offered by the reserve, and the infrastructure provided by the four field stations within it.

Purpose, Setting, and Content

The immediate objectives of the field course were two-fold. First, we wanted to provide students with some hands-on field experience in what is almost certainly the richest (in terms of species numbers) terrestrial environment on earth. The second objective was to expose all students to the daily tasks of the IBAMA staff in patrolling and protecting the reserve, the challenges they faced, and the constraints they worked under. The Amazon’s enormous storehouse of biodiversity makes its conservation globally significant, but many First World solutions are inappropriate, or at least incomplete, for effective conservation in the Amazon region.

The field station used by our group is equipped with functional wet labs, lecture halls, dormitories, kitchen, and a full-time staff (cooks, guards, etc.). It offered an ideal setting by providing a means of staying in close contact with the forest and the river for an extended time, in relative comfort and safety.

Belk, Nelson, and I each offered four classroom lectures (not including the introductory and wrap-up meetings), and augmented these with day and night excursions through the forest, along the river, and/or along the shores of lagoons, to collect and observe many native species of plants and animals (any animals collected were held only for photography, and then released). On the first day, each student received a packet with their name on the cover and an outline of the lecture topics (provided by CENAQUA). Each professor organized handouts for their individual lectures, collated these in the order of their presentation, and, with student help, also placed these in the packets. Students could follow lectures, take notes when needed (lecture rooms had desks, blackboards, slide projectors, and an overhead projector), but focus primarily on what was being delivered by each lecturer.

On the afternoon of 28 October, we had a general introductory meeting in which all faculty and participants introduced themselves. The director of Rebio Trombetas, Alberto Guerrera, briefly described the history of the reserve; its main natural landscapes and wildlife; the duties charged to him and his staff; and the cultural and economic context in which his employees have to carry out the conservation work. Rebio Trombetas was established in 1979, and includes 385,000 hectares (about 950,900 acres) of lowland rainforest along a 100 mile length of the Trombetas River, a major clear-water tributary of the Amazon River.

The reserve contains large stands of upland terra firme forest (forest that is above water all year) with several extensive groves of Brazil-nut trees; low elevation igapó and várzea forests (both seasonally inundated during the rainy season); an extensive network of seventy inland lakes with an intact Amazonian fish fauna; and large nesting beaches for several ecologically important freshwater turtles, including the threatened tartaruga (Podocnemis expansa, the Giant Amazon River Turtle). The health of the forest in this region is indicated by the abundant presence of onça (jaguar), an apex predator that is one of the first species to disappear from tropical ecosystems subject to intense human disturbance.

Cantarelli outlined the history and mission of his own agency, CENAQUA, and the work they were doing to protect and restore nesting populations of several species of heavily exploited native turtles. Students learned that most species of freshwater turtles are hunted for their meat and eggs by ribeirinhos (people of either mixed Indian-Portuguese [caboclo] or African slave [quilombo] descent, who live subsistence lifestyles in the forests along the major rivers). However, a habit of synchronous nesting in large colonies on specific beaches, and a large body size, makes the tartaruga the most vulnerable of all species to overexploitation; this is therefore the highest priority species for CENAQUA’s programs. In the past two decades, CENAQUA has established bases at sixteen major nesting regions in nine different river basins in Brazil’s Amazonian territory, which makes this the most extensive effort anywhere in the world for conservation of a freshwater turtle. Because of this effort, CENAQUA has managed in places to stabilize and even reverse some local population declines.

The background information provided by Guerrera and Cantarelli whetted student appetites, and we returned several times to both themes. Thereafter, we continued a daily routine of lectures and field work through 5 November.

Classroom and Field Experiences

My lectures dealt with two themes. First, the general definition and structural configuration of lowland rainforest communities and how these differ from other forest types. General points emphasized included how patterns of mean annual temperature and rainfall determined the global distribution of rainforests, and how the crown shape and spacing of dominant canopy trees influenced the intensity and angle of sunlight that creates a multilayered structure beneath the canopy layer. Temperate zone students are unfamiliar with the structural complexity of a tropical rainforest, but the geometry of tree shapes is a primary determinant.

The second theme focused on the general issue of Amazonian biodiversity, and hypotheses about possible evolutionary mechanisms that might either accelerate speciation or reduce extinction rates in tropical regions. We spent considerable time discussing hypotheses of riverine barriers, Pleistocene vicariance, and rapid ecological speciation across ecotones and transitional habitats. The latter idea has not been studied at all in the Neotropics, yet it holds enormous potential for improving our scientific understanding of how tropical regions become so rich in species.

Field work associated with these themes centered on general techniques for monitoring amphibian and reptile diversity, and on the nesting biology of the freshwater turtles. For example, we walked transects at night around the perimeter of a nearby lagoon, and located several species of breeding frogs by their calls. Similarly, we established pitfall trapping stations to collect small lizards confined to the leaf litter. Students had to dig holes deep enough to sink large plastic buckets flush with the surface, drive wooden stakes into the ground adjacent to these, and then staple strips of plastic onto these stakes to form barriers stretching across the ground between the buckets. These stations were checked twice daily, and were successful in catching several small lizard species that were otherwise not seen.

Because the timing of our visit coincided with the nesting activity of the tartaruga, CENAQUA staff took small groups of students onto the main tabuleira (beach) each night to observe nesting behavior. This required students to depart the station in the middle of the night, and then to sit on the beach with the guards until sunrise.

No lights were permitted, but students could see the females emerging from the river by moonlight, and watched them first dig body pits, a nest chamber, deposit eggs, and then cover everything before returning to the river. Guards catch the females before they reach the water, and turn them on their backs to immobilize them. At sunrise, a new crew relieves the night patrol, weighs and measures each female, and releases them back into the river. Guards also build small screen pens to fence each nest, and night patrols continue until all nests hatch, when the young are hand-released into the river.

Students learned two important lessons from this work. First, CENAQUA must keep up nightly beach patrols from the beginning of the nesting season through the end of hatching of all nests (about 400 nests were recorded this year at Rebio Trombetas); a period of about 2.5 months. This discourages human poaching and reduces the normal rate of predation. Many nests are 100–200 meters from the river’s edge, and hatchlings suffer extremely high morality from avian predators when they run the gauntlet to reach the river. If not heavily exploited by humans, this natural predation would be an acceptable loss, but under present demographic conditions, CENAQUA must head-start the hatchlings to reduce all causes of mortality on the beaches.

Belk’s lectures dealt with the ecology of fish. The Rio Trombetas’ fish species is the second most diverse anywhere on earth (the first is the Rio Negro upstream). He covered four main topics: interaction of fish with their environment; competitive interactions and feeding strategies; reproduction and mating behavior; and predator/prey interactions. With the Trombetas and many lakes as the backdrop, it was relatively easy to illustrate these points. To illustrate how tolerance limits define habitat use, he took students to two contrasting habitats: a swampy arm of a lake and cutoff pools found on a sandbar in the river. He and students used a small seine to sample the fish in these habitats and discussed differences among species found. In total, the group found over thirty fish species.

One field exercise had students doing multiple removals of fish from the sandbar pools to estimate total population sizes. They learned how difficult reliable data are to come by, and why many conservation decisions are made with incomplete data. One pool was seined over twenty times, and after sore backs and blistered hands, students learned what was required to do thorough field work.

Perhaps the most appropriate lecture covered predator/prey interactions, due to great diversity of predatory species native to Amazonia. Belk illustrated some basic principles at a nearby swamp, where students recorded predation attempts by fish in relation to physical structure of the environment, for thirty minutes. They were to record each time they observed a fish chase something. At the end of this experiment he and the group compiled the data, and clearly demonstrated the relationship between habitat structure and predation.

Insects are the most species-rich group of animals on Earth, and the Amazon is the single most species-rich location. Nelson’s lectures centered on this fact and provided information on sorting through the sometimes mind-boggling variety of insects and other invertebrates that exists at a place like Rebio Trombetas. His lectures followed four themes: collecting, curating, and identifying insects, as well as wildland preservation and conservation. He discussed collecting organisms by hand and with a variety of traps. These techniques were demonstrated during the lecture and then reinforced by frequent visits to the forest, where students gained firsthand knowledge of the immense numbers of species and individual invertebrates present in the various plant communities and microhabitats.

The richness of individual microhabitats was very clearly demonstrated in quickly assessing the forms encountered under a single slab of loose bark of rain forest tree. Our trips to the forest, pool, beach, and river were full of such firsthand information concerning the kinds of animals encountered. Students constantly found more animals to show Nelson and the class. Introductions to each of these particular species were always interrupted by the presentation of the next species in rapid-fire succession. This resulted in the knowledge that the diversity of individual invertebrate species is indeed immense and that the work ahead for insect taxonomists, physiologists, and ecologists is unlimited. Unlimited, that is, if the forest and other habitats are held intact so that the associated plant and animal species are not driven to extinction.

As a matter of proper scientific protocol, Nelson encouraged students to keep field notebooks, and outlined the types of information most valuable to future biologists that may see specimens in museum collections. Students had quick but detailed demonstrations in specimen preparation, which were followed by hands-on exercises in many of these techniques. Students also explored specimen identification in both lectures and wet lab situations. In this identification section, two exercises stand out in their particular success.

First, in the classroom, students determined common names, in local terms, for a wide variety of insect scientific names. This was a wonderful learning experience when the standard Latin names of groups of insects were translated into the common names used by the students, both Portuguese- and English-speakers. Students became animated as they voiced adamant opinions regarding the appropriate common names for each organism. This pointed out the need for standard scientific names as well as a working understanding of the common names used by local people in a region. We summarized, on a conservation note, that the need for communication is paramount and outweighs petty disagreements.

Second, in the wet lab, students viewed a variety of insects collected in a trap, which required sorting the trap samples into the huge number of species encountered. Microscopes were available and each person viewed the interesting forms under magnification, while Nelson helped them interpret what they were seeing. This gave students a direct view of body form adaptations that individual species have to deal with their particular environment.

All discussions were tied to the need for conservation of biodiversity in the face of competing human needs. It was pleasurable and informative to make these associations in the lab and field setting offered at Rebio Trombetas. Students greatly benefited from the coupling of lecture with hands-on activities and were surprised by how difficult it was to collect good data in the field.

Take-Home Lessons

Cantarelli and the CENAQUA staff gave all of us several informal lectures on sustainable rainforest resources usage, and IBAMA staff followed with examples of the challenges posed on them to enforce laws and carry out their conservation mandates. Given the size of the reserve, IBAMA is understaffed for the complete development and implementation of a science-based management plan. They maintain four permanent bases in the reserve, each with a staff of two to three people. The size and shape of Rebio Trombetas—the fact that it stretches along 100 miles of the Trombetas River—makes it impossible to effectively patrol. Invasion from either side could be unstoppable if the human population density outside of the reserve ever increases to a large size. Cantarelli estimates that IBAMA would need to maintain about eight permanent bases, each with a staff of four to five full-time employees, to effectively manage the reserve.

Some local examples gave students a better idea of specifics. In one case, local people are permitted in the reserve to harvest Brazil nuts when these ripen and fall, but this requires that they build temporary shelters and spend perhaps one to two months in a single spot (near a grove of these trees). Normally two or three young men will do the nut collecting, but they must usually kill one or two animals per day to eat (monkeys, armadillos, agoutis, etc.) throughout their stay in the reserve. The IBAMA staff estimates that this adds up to a loss of 2,000–3,000 animals each year from the reserve. If local people were denied access, they would likely retaliate by killing animals throughout the year, and therefore remove even larger numbers. For the present, the seasonal harvest is the only option.

A second example describes the problem of poaching for selected species of fish that are common in the lakes and lagoons of Rebio Trombetas. Again, because of the shape of the reserve, staff and budget constraints do not permit continuous patrolling of all relevant habitats, so poaching is not uncommon. However, many people catch common species for their own consumption, such as the peacock bass or tucunaré, and IBAMA does not worry about this harvest. Indeed, their staff caught these fish daily to feed us—the biomass seems immense.

A second form of poaching centers on the large pirarucú, a species highly prized for its meat. In contrast to many species, local people hunt piraruc˙ for illegal commercial sale to restaurants in Belém and Manaus. One large specimen (this fish can grow to two meters in length and attain a weight of 100 kg) was confiscated from a poacher during our stay, and IBAMA is as diligent about protecting this species as funding and staff will permit.

The third type of fish poaching is done by large-scale commercial fishermen. Although rare, occasionally a very large, well-equipped vessel will motor its way up the Trombetas River and attempt to off-load a fleet of smaller boats to invade one of the large lagoons with gill nets. This was last attempted in early 1999, and IBAMA’s own large boat met the intruding vessel. After an exchange of gunfire, they overtook the vessel, arrested the crew, and confiscated the equipment. Fortunately no one was injured, but processing the arrests required a ten hour boat trip downriver to the nearest large town—Oriximiná—to put the suspects into custody with the federal police—something that IBAMA cannot afford to do frequently, so they must carefully choose their battles to leverage the most gain for conservation with each arrest.

The final and most detailed example of their conservation efforts, and the trade-offs they face, is freshwater turtles. Three species have been heavily exploited for meat and/or eggs. As mentioned before, the largest and potentially most vulnerable of these is the colony-nesting tartaruga, but two smaller species are abundant and also exploited: the tracajá and the pitiú. The tracajá is a solitary nester, and uses not only exposed sandbanks and gravel bars, but also mud flats of the igapó forest. Because of these dispersed nesting habits, IBAMA does not have the manpower to patrol for protection of this species, but it is less vulnerable and its populations appear to be stable.

On the other hand, the pitiú selectively nests in groups on the exposed beaches also preferred by the tartaruga, but begins two months earlier. IBAMA does not regularly patrol beaches to thwart poaching of pitiú nests. During my 1999 visit to Rebio Trombetas, I saw fresh human tracks and excavated nests everyday during the nesting season of this species. Cantarelli told me that one of his objectives, and one reason for the BYU invitation to develop the field course, was to simply increase use of the reserve. His argument was that increased visitation and use, even for short periods of time, would increase both the public profile of the reserve— therefore it’s value—and indirectly discourage some illegal transgressions because of the sheer presence of people unknown to the local ribeirinhos.

On this trip, students met the Brazilian graduate student, Erica Hallar, a master’s candidate from the University of São Paulo. Hallar had been at Rebio Trometas for almost three months prior to our arrival. She was conducting an intensive study of the nesting ecology of the pitiú. This involved tracking females at night when they emerged to nest, marking the nests, capturing females on their return to the river to collect weights and measurements, and then monitoring nests until they hatched. She had implanted thermocouplers in some nests to record the temperature of the nest chamber every thirty minutes, throughout the incubation period (55–60 days). She also transplanted a total of forty nests to incubation boxes at the field station for more controlled studies of the influence of nesting temperature on the differentiation of sex in the hatchlings. Like many turtles, sex is not genetically fixed upon fertilization of eggs, but rather determined by the incubation temperature during the first three weeks of development.

Hallar gave one guest lecture on the details of her work, which the students found fascinating, but the significance of her work is that it appears to bear out Cantarelli’s approach to increased reserve use. At the beginning of her study, Hallar visited the nearest caboclo and quilombora communities in the vicinity of Rebio Trombetas and explained the purpose of her stay, and what she would be doing. Unlike the 1999 season in which pitiú nests were heavily poached on the main beach, there had been no poaching in the 2000 season. Simply because a twenty-four year-old woman had, along with one IBAMA guard, maintained a nightly patrol, the beach has been empty of all people except the researchers.

David Gonzales, a zoology major, had worked with Dr. Belk for one and a half years, including a survey near Tropic, Utah. That was the first Gonzales heard about Brazil. “It was the chance of a lifetime,” he said. “I will focus my studies to become a scientist/researcher in field-based ecology,” Gonzales decided after his Amazon adventure.

While on a mission in Costa Rica, he first became aware of rainforest issues. His experience in Brazil only added fuel to his quest. “Knowledge is power. Seeing brought understanding and gave focus to how my passion could be played out,” he said.

Mindy Wallentine, a wildlife biology major and December 2000 graduate, was invited by Dr. Sites to join the research team in Brazil. “I am an environmentalist,” Wallentine said. “This trip cemented things for me. My learning came primarily from textbooks as a vague concept.

Now I have talked directly with the people involved. I saw the political and scientific sides,” she said.

When asked about the insects, she reassured that this was a trip during the “dry” season, and they encountered “only two mosquitos.”

“This was the capstone of my undergraduate experience. I didn’t know what to expect. It was amazing— better than I imagined,” she said.

For many reasons, IBAMA puts most of their time and effort into protecting the large female tartarugas when they come ashore to nest—often dozens in a single night. They are aided by considerable support from ProTartaruga, a non-governmental organization, that has successfully used the big turtle as its poster child to raise public awareness of turtles and the Amazon’s wild nature in general. They now have sufficient public support and funding to annually loan at least six full-time staff to IBAMA’s work in Rebio Trombetas during the tartaruga nesting season. After the last nest hatches, Pro-Tartaruga employees then relocate to another CENAQUA station, where additional manpower may be needed for the same reason.

This is equivalent to the National Park Service being loaned full-time employees from a citizens group, such as the Nature Conservancy (TNC), at Yellowstone National Park, when the elk begin to drop calves. As soon as calving season was over, the TNC employees might then pack up and head for Glacier National Park, where calving would occur at a different time. This arrangement was a real eyeopener to all of us from the U.S., as we could never imagine something like this being needed here.

It is all the more remarkable because the beach guards are occasionally defending turtles at personal risk. Two IBAMA employees were wounded by shotgun blasts at Rebio Trombetas in the past five years, when approaching poachers on beaches at night. Although rare events, they do serve as a reminder that most of the Amazon region is still a frontier forest that requires people to travel in groups and be on the alert.

On our last full day in Rebio Trombetas, we all met again with Guerrera for an open discussion for the purpose of feedback to the three professors. We wanted to know what they liked, what they did not care for, and how we might make improvements if given another opportunity. This was also a chance for us to extend out heartfelt thanks to the IBAMA guards and station staff who worked so hard to make our visit pleasant and safe. I personally let the Brazilian students know how much time Cantarelli spent lobbying his superiors, and the mining company, to secure financial support for all of them to travel to the reserve to join us for the course. The response from all of the students was immensely favorable. To a person, they benefited tremendously from their participation in this experience with us and by their interaction with each other. In the end, they forgot about the heat and insect bites. Their minds had been expanded with new challenges and possibilities.

I know of no better way to provide students with a deeper understanding of any natural ecosystem on earth than to show them firsthand what these environments are like and to design teaching experiences that require them to do hard field work. I think we accomplished this at Rebio Trombetas, and with a little luck, maybe even helped initiate a research program designed to generate good science, educate students in the process, and integrate science into reserve management. A further challenge will be to broaden the discussions to include the surrounding caboclo and quilombora communities in a dialogue on sustainable resource usage. Only by successfully integrating these communities into long-term conservation goals will poaching of turtles, selected species of fish, and large mammals ever really be controlled. BYU and Brazilian students gained a more in-depth understanding of tropical biology within the larger cultural and economic context that is the reality of Amazonia.