Venomous River: Changing Climate, Imperiled Forests, and a Scientist's Race to Find New Species in the Congo

by Eli Greenbaum

Join herpetologist Eli Greenbaum on his race to identify a multitude of unidentified species in the Congo, a volatile African region overcome with population pressure, military oppression, and climate change. These are the backdrop challenges to the science pursued by Dr. Greenbuam in this timely work worthy of Darwin.

Venomous River chronicles a field scientist’s search for new species in the Congo Basin, one of the world’s great crucibles of biodiversity, in the face of climate change. Although tropical forests cover less than 10 percent of Earth’s land surface, they are home to about two-thirds of the planet’s terrestrial biodiversity. Unfortunately, a ballooning human population has severely damaged half of the planet’s pristine ecosystems and the biodiversity they contained, leading to an unfolding sixth mass extinction.

In Joseph Conrad’s famous 1899 novella Heart of Darkness, he described the Congo River as “a great snake.” More than a century later, herpetologist, evolutionary biologist, and seasoned expedition leader Eli Greenbaum set out to find the Democratic Republic of the Congo’s (Congo for short) incredible diversity of serpents in the flesh, along with the country’s rarest frogs, lizards, crocodiles, and turtles, which live in and along Africa’s second-largest river. For a biologist, an expedition into the heart of the Congo is a priceless gift, with its incredible species, known and unknown, lurking around every bend in the river. But the Congo is also a place of endemic political instability, widespread corruption, human suffering, and extraordinary danger. These, as much as the challenges of the natural world, confront any scientist doing field work in the Congo.

Venomous River is the harrowing story of a biodiversity scientist’s successful quest to discover several new amphibian and reptile species in the remotest heart of Africa, a wilderness where he encounters friendly peoples, a cook who is revealed to be a dangerous killer, highly venomous snakes and scorpions, deadly tropical diseases, and troubling echoes of the Congo’s colonial history.

Genres: Nature

288 pages, Hardcover

Published October 21, 2025

About the author

Eli Greenbaum is a professor of biological sciences and the director of Biodiversity Collections at the University of Texas at El Paso. He is a world expert on the amphibian and reptile fauna in Central Africa and has published over 125 studies in peer-reviewed scientific journals and books. His work has been covered by CNN, Newsweek, The Washington Post, NBC News, National Geographic Daily News, Africa Geographic Magazine, Reptiles Magazine, and The Huffington Post. He is the author of Emerald Labyrinth: A Scientist’s Adventures in the Jungles of the Congo, a Forbes magazine “Top 10 Science Book” of the year. His latest book is Venomous River: Changing Climate, Imperiled Forests, and a Scientist’s Race to Find New Species in the Congo.

Reviews

[Ryan · Rating 4 out of 5]

The author spent more than fifteen years in multiple expeditions to Central Africa, and this book is the second account of his later trips, though it seemed to have taken place in 2013, quite some time before the publication date. Be that as it may, Greenbaum managed to provide another engrossing account of the trials and tribulations faced by a modern scientific field survey team in the wilds of the dark continent. This time he plunges into the Heart of Darkness, the Congo river and its mid to upper tributaries in the quest for more herpetofauna. The haul appeared to be better than in the last trip further east, as perhaps expected from the more biodiverse lowland humid tropical rain forest flanking the famous river. Instead of hazardous overland journeys over muddy roads in the previous book, there are slow meanderings in the river on rickety wooden boats. The pygmy people encountered along the way were more than hospitable and proved to be expert at obtaining the specimens sought by the team, making the task easier than before. The tale was made more intriguing with the addition of a mysterious and sinister cook to the team, whose unpredictable behavior was matched by his unexpectedly superb culinary skills.

The usual sidetracks into history, viruses, tropical diseases and general conservation issues were interspersed with the travel narrative, but were brief enough to pique interest without becoming overwhelming.

[Les Gehman · Rating 5 out of 5]

There is a whole lot of information and adventure packed into this relatively short (about 200 pages without the notes and references) book. The author documents their expedition up the Congo River to discover new species of reptiles and amphibians, and to add to the knowledge base of known animals. He does a great job of setting the scene regarding both the natural environment and the human environment that he encounters, often explaining history and human/animal interactions that have influenced the current environment. The book is very well documented with notes and references for those who wish to explore the subject further.

[Weston Kiser · Rating 3 out of 5]

I read a fair amount of these scientific research books as well as memoirs by adventurers (hikers, climbers, mountaineers, etc.). I try to remind myself in both cases these people are not authors by nature. This book is a classic example. Lots of info packed in with an attempt at some storyline of crew disarray to keep you hooked. However mostly it was a lot of “saw this snake, then saw this snake, after we saw this snake”