The Science Behind Houseboat Amazon

What if you had the opportunity to follow a woman-led science expedition into the deepest, most unknown reaches of the Amazon, knowing it would invoke the same sense of wonder, passion, and excitement as watching someone wrestle a caiman or leap from a cliff in a flight suit?
— Dr. Laura K. Marsh, Expedition Leader

During high water season, we sailed a houseboat along the Upper Rio Juruá watershed in western Brazil, to conduct the first-ever full mammal survey of this remote region, and to search for a monkey that had not been seen alive by science in over 80 years. We showed the world what real science and real adventure look like! And if you follow our blogs, podcasts and documentaries, you can continue to participate in real science and adventure along with us!

We are all familiar with adrenaline-pumped media adventures where people challenge themselves with new hot equipment as they hurtle down the river, mountain, snow, sky and ocean. Or entertainment shows where people capture dangerous, rare, or difficult creatures to demonstrate the thrill of it. This project was about diving into exploration. It was about shedding preconceived notions of science and adventure, and wrapping all who joined us in the awe that is the daily discovery of the Amazon rainforest.

The journal where Dr. Marsh published her findings.

The journal where Dr. Marsh published her findings.

We started with a museum mystery. In the 1930s, the Olalla Brothers, known for their collection of wild animals for museums, hunted 36 individuals of the now missing saki monkeys. The skins from these monkeys are now preserved in four different museums.  

When Houseboat Amazon expedition leader Dr. Laura K. Marsh revised the saki monkey genus [Here (Part I) and Here (Part 2)], she discovered that one species, Pithecia vanzolinii, had not been seen or photographed alive since they were originally collected in the 1930s. They seemed to have vanished from science. All science knew about this species was from the skins and skulls. We could only guess about how they lived, what they ate, and how they fit into their ecosystem. Thus we had a rainforest detective story.

The Houseboat Amazon Science Expedition included an international team of seven wildlife professionals from Brazil, the U.S., Colombia, and Mexico; a Cruzeiro do Sul-based houseboat captain and crew; Brazilian students and scientists; and a group of rural guides.

We lived on rivers among lush, untouched, 100-foot trees covered in their own communities of bromiliads, rainbow-colored poison dart frogs, thigh-thick lianas, toucans and scarlet macaws, oscelots, and roaring howler monkeys. ‘

Pithecia vanzolinii. Female and male.

Pithecia vanzolinii. Female and male.

Parauacus, or flying saki monkeys, is a genus of monkeys that are medium-sized, quiet, cryptic, live in small groups, have huge canines for cracking hard-shelled nuts, and run so lightly through the treetops it seems like flying—with their fluffy, non-prehensile tails waving behind them.

The target species, Pithecia vanzolinii, are distinctive monkeys like no other primate that might live nearby. They are especially notable for their buffy-colored arms and legs. They were named for Pablo Vanzolini, a famous Brazilian biologist and musician.

We conducted surveys to document all of the amazing mammals in the watershed and to search for the missing monkey using four small canoes. We ventured out from the houseboat “floating research base” every day. Each of the team members worked with a local guide in terra firme, igarapes, or flooded and unflooded forest.

We used all kinds of tech in the field and on the houseboat including: GoPros, Nikon and Canon cameras for stills and videos, a Panasonic AC90 camcorder, night cameras, GPS, computers, and drones for searching from above, helping us to identify open waterways and collect video about the uncharted forest canopy.

We worked and sailed during high water season to maximize the chances of finding mammals and the monkey because navigating dense rainforest when it is flooded is often easier to survey by boat than on foot. During high water season the rivers can fill to depths of 50-feet.

We worked and sailed during high water season to maximize the chances of finding mammals and the monkey because navigating dense rainforest when it is flooded is often easier to survey by boat than on foot. During high water season the rivers can fill to depths of 50-feet.

The original Pithecia vanzolinii specimens collected in the 1930s were found near a town called Eirunepe (upper right on the map), which, for us, required four days of sailing downstream from Cruzeiro do Sul on the Rio Juruá. We had a base of operations in Cruzeiro do Sul, the only major city in this part of Amazonas State. We gathered the rest of our team and stepped off for the expedition out of Eirunepe in January 2017. We wanted to study in this area because, at present, the Upper Juruá watershed between Rio Tarauaca and the Juruá is the only known range for Vanzolini’s saki monkeys.

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Our houseboat!

Our houseboat!

To conduct surveys on igarapes (small streams) or in igapo (black water) or varzea (white water) flooded forest, we used small boats or handmade canoes with paddles.

To conduct surveys on igarapes (small streams) or in igapo (black water) or varzea (white water) flooded forest, we used small boats or handmade canoes with paddles.

We covered these main river channels to conduct the comprehensive survey and to look for Pithecia vanzolinii. The houseboat was based along the river channels and changed location every few days. Small boats fanned out from the houseboat to conduct the detailed search and to document everything the researchers observed.

We covered these main river channels to conduct the comprehensive survey and to look for Pithecia vanzolinii. The houseboat was based along the river channels and changed location every few days. Small boats fanned out from the houseboat to conduct the detailed search and to document everything the researchers observed.

We did not just look for the target species. Because there had never been an expedition for mammals, including primates, into this area, our team recorded all kinds of amazing rainforest creatures: caimen, piranhas, anacondas, jaguars, pumas, ocelots, tapirs, capyberra, pink and grey dolphins, otters, twenty species of primates—a total of 80 species of mammals—AND thousands of birds, insects, reptiles, and fish!

The region where these monkeys were last seen is one of the last bastions of intact rainforest of incredible biodiversity, with the potential of >600 bird, >200 mammal, and >130 amphibian species. The watershed, some 43,000 square miles, does not fall within Brazilian nationally protected habitat.

Below are images of some of the animals we encountered. No one knew what species lived in the area because a large-scale survey of this kind had neve been undertaken. We didn’t know what we would find and we had lots of surprises!

Mounting this expedition meant that there were sure to be new discoveries, even if our motivating goal was to find a missing monkey species.
— Dr. Laura K. Marsh

A very important part of our survey work involved meeting people in rural communities who knew the area well and who could tell us about what they hunted for food. 

Although this region is remote and difficult to access, it is increasingly encroached upon by the expanding demands of urban populations. Local rural villagers hunt and fish without limits. Worrisome potential future plans by the Brazilian government to incorporate the watershed into Florestas Nacionais would allow large-scale timber extraction concessions with roads, large trucks, and wholesale deforestation. Greater governmental influence would also allow for continued exploration for oil. Finding even a modest reserve would mean devastation to the waterways, the people, and the forest. The fear in far western Amazonia is that the study area will become part of the “Arc of Deforestation” that has ravaged nearby Rondonia.

We were engaged in “muddy boots” research involving high-tech activities that called attention to this remarkable species-rich area of the Amazon. 

To do this, we promoted international collaboration through our excellent social media campaign, which included a wide global audience and made it possible for rural, local, and city school children, students, and the public to participate. 

In modern society, we are disconnected from nature. We yearn to touch our internal wild-ness. We suit up, go to work in an indoor office and hunger to be connected to something native, raw, intense. When viewers follow the expedition, they see wildness existing somewhere, affirming that it also exists in them. Our intention with Houseboat Amazon is to remind us of who we are at our core: intense, curious, and excited.

Now that the expedition is over, we invite you to join us through our blogs, podcasts and documentaries as we re-live five months on a 60-foot houseboat, where three languages (Portuguese, English and Spanish) are spoken.

Find your passion hidden in a tangle of vines, the splash of a pink dolphin, or the flutter of a giant blue morpho’s wings. And maybe, just maybe, find it in a fluffy missing monkey.

Become the wild in wilderness. Join us to find your heart in the jungle. 


Global Forest Watch has put together a global forest interactive map that shows the change in total forest cover and infrastructure of the zone we explored. Click the map to interact with the information: