Encountering Wildlife Icons in Bolivia’s Llanos de Moxos
By Rob Wallace | June 26, 2025
We all thought it was a good omen. As we approached the Gran Mojos Municipal Protected Area, the car in front of us slowed down and people poured out of the vehicle, pointing at a tree. A subadult harpy eagle (Harpia harpyja), the most powerful bird of prey in the world, stared down at the group of excited biologists.
For many of the group it was their first good look at this Latin American icon, and for ten minutes or so we all stared wide-eyed before this massive raptor launched itself and flew off into the surrounding forest-grassland mosaic. We were all still buzzing at the expedition launch event in Loreto, 54 km south of Trinidad and the capital of the municipality of the same name.
Later that afternoon a fleet of 11 peque-peques (wooden canoes with a small, air-cooled engines) left the nearby town of Camiaco on the Mamore River — a major tributary of the Madeira River, itself the largest tributary of the Amazon — towards the mouth of the smaller Isiboro River. The first camp of this fourth expedition to the vast Llanos de Moxos of the Beni Department of Bolivia was situated further up the Isiboro.
The Moxeño and Yuracare acted as guides, piloting the peque-peques, sharing knowledge of plants and animals, and helping identify potential archaeological sites.
The Wildlife Conservation Society (WCS) has been supporting this protected area and at the request of the municipal authorities, we committed to generating biodiversity and archaeological information there. The Moxeño and Yuracare peoples acted as local guides — piloting the peque-peques, sharing knowledge of the local plants and animals, and helping to identify potential archaeological sites.
A fleeting glimpse of a jaguar as it crept from the Isiboro River into the forest, and an early morning yelp of the elusive maned wolf, suggested that the Indigenous communities and the municipal authorities are successfully protecting wildlife. Across the expedition, we encountered and recorded jaguars repeatedly. This is great news, as jaguar numbers appear to be higher than other areas we have visited in the Llanos de Moxos. Along the Pojige River, the team also registered another signature species, the magnificent marsh deer.
It is too early to tell whether the expedition uncovered any new species for science. Biologists from the Museo Nacional de Historia Natural Colección Boliviana de Fauna, the Centro de Investigación de Biodiversidad y Medio Ambiente (CIBIOMA), the Centro de Investigación de Recursos Acuáticos, and WCS are busy compiling lists and confirming identities.
As we raised camp on the Isiboro River, Amira Negrini and Huber Villca — botanists from the CIBIOMA — explained to me that whilst the rainforest along the Isiboro was not especially diverse, they had registered many examples of a new tree species. Alfredo Fuentes and Freddy Zenteno, two colleagues at the National Herbarium, were in the final stages of describing this new species, Sarcaulus, from the Sapotaceae family. When I asked if I’d likely seen it, Amira and Huber pointed to the tree they had pitched their temporary laboratory under at camp!
The Llanos de Moxos Working Group has systematized archaeological data across the region. The number of known archaeological sites now numbers more than 9,000.
Meanwhile, Geraldine Fernandez from the University of Bonn was busy documenting known archaeological sites, including several raised earthworks, or lomas, along the Isiboro and Pojige rivers to which she would later return to map and measure. The Llanos de Moxos Working Group has systematized archaeological data across the region and, incredibly, the number of known archaeological sites in the Llanos de Moxos now stands at more than 9,000.
At the third camp, on a ranch on the shores of the shallow Anteojos lake, we enjoyed a series of intense wildlife encounters. Thirsty coatis, tayras, agoutis, capuchin monkeys, collared peccaries and — especially — a brocket deer risked crossing the beach. This activity was temporarily paused as a strong south wind blew through for a couple of days, dropping temperatures 20 degrees C, inching up the shoreline 30 meters, and threatening our tents.
To close the expedition, a small group of us traveled to another ranch, La Cantina, to observe an endemic but rarely sighted Bolivian wildlife icon: the blue throated macaw (Ara glaucogularis). For thirty-five years, I’d heard about this spectacular but Critically Endangered bird whose population is down to just 300 individuals. I’d read about the conservation efforts of Armonia, Fundación por la Conservación de Loros de Bolivia, and others.
Shortly after our pre-dawn arrival, I heard the birds in the morning mist before spending a wonderful hour observing a pair. During the trip, our ornithologist colleagues Victor Hugo Garcia and Rafael Mounzon explained that the Gran Mojos Municipal Protected Area is home to one of the three most important populations of the species and is therefore a major conservation priority.
The Gran Mojos Municipal Protected Area is home to one of the three most important populations of blue throated macaws and is therefore a major conservation priority.
As I left the macaws with a beaming smile, I was pointed in the direction of a family group of the black and gold howler monkey. I held my breath as I watched a baby perform gymnastics on her mother’s head. Returning home, I carried with me a profound understanding of the incredible wildlife observation opportunities offered by the Llanos de Moxos.
Rob Wallace is Director of the Llanos de Moxos Biocultural Landscape and the Greater Madidi-Tambopata Landscape Conservation Programs of WCS in Bolivia.
