Saturday, 11 August 2007

Ay Corumbá!

Originally published (and since removed from) my old blog, this is a summary of my trip to Brazil last September.

Howler

SÃO PAULO is several worlds away from Europe. A twelve-hour flight from Zurich airport, itself a boastful demonstration of extreme wealth and extravagance compared to Birmingham, the largest city in the Southern hemisphere is home to some 19 million people. The industrial centre of Latin America, the city is bustling and prosperous. Despite this, one cannot escape the fact that the first sight visible to those leaving the airport is of a favela, a Brazilian shantytown. However, before we had chance to absorb such a culture shock, we were being whisked away in an air-conditioned coach across bumpy roads and out of the city, passing alongside the ominously shiny River Tietê and out through miles of forest and sprawling countryside to the city of Rio Claro.

The field project was run in collaboration with the Institute of Biology at Universidade Estadual Paulista (UNESP), the University of São Paulo state, based at the Rio Claro campus. This was an open plan campus, with students, tegu lizards and horses alike wandering between buildings. It was here that we spent our first few days, with emphasis on the study of animal physiology. We dissected lizards, fish, birds, rats and frogs, taking detailed notes of two areas of focus: circulatory systems and muscle composition with relation to function. Those amongst you with ethical objections may take some solace in the knowledge that the animals killed were farmed specifically to feed the hundred or so caiman kept in enclosures outside. They were fed directly to the crocodilians immediately after we had finished our research and were not, as such, killed simply for us to experiment upon them.

Each new day at the UNESP lab (nicknamed the “Jacaresario”, meaning “Caiman Room” in Portuguese) presented a new surprise. On only our second day our entrance was blocked by feeding vultures, a tour of the other rooms of the facility put us face to face with rattlesnakes, anaconda and pregnant boa constrictors and while we sat on the grass outside eating our lunch a pair of toucan watched over us.

Forest stretched to the horizon from the back of the laboratory and on the fourth day we hiked for an hour or so down dirt tracks in the shadow of inconceivably tall trees to a coffee plantation that lay in the heart of it. Now a National Park, the Floresta Estadual was part plantation and part eucalyptus forest, planted by the British to use for railway sleepers. The surrounding semi-natural forest provided our first opportunity to explore in the wild, where we marvelled at unique flora and formed an audience around a trail of somewhat hurried leafcutter ants.

Over half of our group were to return to Rio Claro and take up physiology projects for their dissertations, but for now we all checked out of our hotel, packed our bags once more and settled down for a coach journey to the state of Mato Grosso do Sul. Distances in Brazil are so incomprehensively vast that this journey took eighteen hours, and yet we really only covered a small portion of the country. The Amazon basin, by comparison, some 2,500 miles to the North West of São Paulo would take days to cross (with some difficulty). Our destination was Passo do Lontra, a village and ecotourism hotel in the Pantanal. An area the size of France, the Pantanal is the largest wetland in the world and contains perhaps the richest of the world’s biodiversity.

Spot the Howler Monkey...
A taste of the Pantanal

120km from Corumbá on the Bolivian border, the hotel was a series of chalets and a restaurant on stilts, connected by boardwalks that were elevated over land that would flood in the wet season, transforming the landscape from the dry forest with isolated pools and lakes as we saw it (it was approaching the end of the dry season during our stay) to a landscape of 80% water. To get there our coach had to turn off the sole surfaced road through this vast area and navigate narrow dirt tracks, lined either side by steep gravel banks, at the base of which countless caiman lay basking in the midday sun. The passing noise of the engine disturbed flocks of jabiru storks - the second largest bird in the world and the symbol of the Pantanal - and upon reaching a wooden bridge over the Rio Miranda we all had to alight for fear of the bridge collapsing. Needless to say, the hotel was somewhat remote.

The first few days of our stay were spent exploring the local area, learning about the Pantanal, and having a little fun to boot. We travelled on a trailer out to a local farm, or fazenda, where we went horse riding through the marshy waters (much to the horse’s disgust), caiman spotting at night (in preparation for one of the studies, where two people in our group caught wild caiman at night to take blood samples and chart species health) and slept in hammocks, all while being taught of local history and wildlife. We observed beautiful blue hyacinth macaws, land crabs, armadillos, howler monkeys and plenty of resident caiman. We then returned to the hotel site, an hour south, where we raced canoes down the Rio Miranda, teeming with caiman, leeches, stingray and anaconda. We also fished for piranha and later tucked into the sumptuous local cuisine before retiring to bed to the sound of countless insects and, rather worryingly, a bat residing within our ceiling.

Of course, the trip wasn’t all about having fun, so we bade farewell to over half the group who were to return to Rio Claro to begin their physiology projects and began behavioural projects of our own. Along with my project partner Jenny, we spent the next ten days conducting a study of a group of black-and-gold howler monkeys (Alouatta caraya) whose territory overlapped with the hotel. Another pair of students were studying tail use and positional behaviour in the group, but we were trying to quantitatively assess the effect of ambient temperature on the species.

The project was an extension of a 1998 study by Júlio César Bicca-Marques and Cláudia Calegaro-Marques, who had attempted to test a theory proposed by Thorington et al. in 1979 that the phylogeny of sexual dimorphism in the species could be explained by behavioural thermoregulation. That is to say, the difference in coat colour between males and females (black and gold respectively) might confer an advantage to different individuals at different times of the year in terms of body temperature and associated activity. Thorington argued that this advantage might be able to explain why the sexes became different colours in the first place (i.e. that it is an evolutionary advantage). This competes with a separate theory by Crockett in 1987 that explains the difference in coat colours by means of mate selection by females. Our study intended to examine the general effect of temperature considering other variables and the use of positional behaviour.

Hiding in my notebook

Using statistical methods developed for behavioural studies since the Marques’ paper, we recorded nine separate variables for each type of individual (adult male, adult female, juvenile and infant) each minute for focal hour periods for eight days. This began when the monkeys became active (typically 5.30am) until they settled in a sleep tree for the evening (typically 6pm). Simple enough to collect data, it was still notably difficult to work for such long, intense periods in heat that reached 38°c in the shade. However, we enjoyed the experience of roaming wild territory, having the privilege of observing a wild family of monkeys (consisting of ten individuals of all personalities, from the playful infants to doting mother and consorting adults), and our subsequent data set was so large it allowed a wealth of opportunities for theory exploration and further study upon return to the UK. Our data set was so large, in fact, that it took two weeks to enter into our statistical analysis software upon return.

Despite being called ‘Howler’ monkeys, our group were ominously silent. Every morning we could hear the roar of nearby groups, but ours seemed content to grunt and huddle, and only call out if other groups were particularly loud. It is possible that this is the case because of the relative safety of their territory. To the North a treeless swamp formed a permanent boundary occupied by basking caiman, wallowing capybara (who were the subjects of the final behavioural study on site) and the unfathomable behaviour of the caracara. To the South the Rio Miranda formed a permanent boundary, with other monkeys having been spotted on the far bank. To the West, territory thinned into swamp and was perhaps the only sight of invasion by another group. To the East the forest ended abruptly. This area was, fortunately, only visited once by our population, since for us it was particularly uncomfortable. Insects of unimaginable numbers insisted upon making our observations in that territory notoriously difficult. Despite using the strongest insect repellent available - which repeatedly melted our stationery - nothing could hold back the pernicious bloodsuckers, and brief visits to open ground became routine on those days. Of course, even ‘open ground’ had its fascinating quirks, from termite-infested trees, to “Cobra Log” and ants the size of fingernails particularly fond of my shirt.

Toucan

At the end of the study period, we took one last boat trip in search of drinking jaguar. Alas, the prodigious cat who we had heard while wandering the woodlands was to prove too elusive on our last day in the Pantanal, but we did get one last chance to share the waterways with giant otters, kingfishers and a host of exotic birds, while watching marsh deer, iguanas and jabiru storks in their conspicuous nests on the river bank. Then, our bar bills settled, we returned to Rio Claro, to catch up with the remaining half of the group, present our findings and observe their experiments in action.

This was also a final chance to experience Brazilian culture and a chance to put our expert linguistic skills to the test. Despite being so isolated, the ecotourism nature of the hotel in the Pantanal meant that all guides on site were fluent in English, in order to tell passing American ornithologists and amateur wildlife photographers of the wonders of their part of the world. Rio Claro, on the other hand, was so far off the beaten tourist trail it was difficult to even find anyone who spoke Spanish, the first language of almost every other South American country. This was not, by and large, a problem, but there were occasions when frantic gesticulations and a scattered mosaic of English, Spanish and presumed-Portuguese were necessary. Buying stamps, for example, has never been so difficult.

And then, when things had barely got going, we were back on that coach to São Paulo airport and heading back to Europe. Behind us lay the wonderfully vibrant and diverse country of Brazil, whose wildlife had entranced us, insects bitten us and locals taught us to dance. All of us came back with a passion to return, and explore and research further. Before we could do that however, we had 69,839 individual data points to analyse…

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