The Huge Impact of Africa’s Teeny-Tiny Crocs

Dozens of pairs of eyes gleamed back at Matt Shirley as he swept his flashlight through the fetid darkness of a bat guano–spackled cave. It was 2010, and he had joined a group of French scientists on a survey of the Abanda Caves, a limestone labyrinth in Gabon’s coastal rainforest. The team, he realized, was surrounded by crocodiles.

For many people, this would be terrifying, but for Shirley, a conservation ecologist at Florida International University and a Rolex National Geographic Perpetual Planet Explorer, it was exactly why he’d come to Gabon. The animals were African dwarf crocs, the world’s smallest crocodile species and the subject of the Ph.D. research Shirley was conducting in Africa. Now, as the team pressed deeper into the caves, one of the spelunkers, to his alarm, came face-to-face with a five-foot-long crocodile. The crew carefully hoisted the creature to the surface, where they washed away its grime and gawked. Whereas most dwarf crocs are jet-black, this one was bright orange. This is absolutely crazy, Shirley remembers thinking.

Although Gabon’s pumpkin-hued troglodytes are especially bizarre, all dwarf crocs are remarkable in their own right: resilient, adaptable animals with a penchant for breaking the usual crocodilian mold. In contrast to huge and fearsome cousins such as Nile crocodiles, dwarf crocs are timid creatures that have an average length of around five feet and emerge from burrows at night to scurry after crabs, frogs, and millipedes. This scaled-down strategy has proved wildly successful for dwarf crocs, which range from the West African coast to the continent’s interior and thrive in a variety of ecosystems. Today, though, dwarf crocs, an important source of protein for many people in West and Central Africa, are imperiled by commercial overharvesting and habitat loss. These conservation challenges are largely exacerbated by a lack of funding for research into the small, reclusive reptiles. Compared to charismatic mega-mammals like elephants and apes, Shirley says, dwarf crocs “slip through the cracks.” 

Shirley is a lifelong reptile-lover whose mother obligingly retrieved the snakes that frequently escaped from the terraria in his childhood bedroom. He’s spent years working alongside scientists across Africa to illuminate the secret lives of dwarf crocs—especially in the Abanda Cave system, whose subterranean reptiles illustrate just how tenacious dwarf crocs can be.

In the years after his initial expedition to the caves, Shirley and his colleagues strove to understand how the cave’s inhabitants fit into Osteolaemus, the dwarf croc genus, which his surveys of populations around Africa had already helped separate into three closely related species. Again and again he returned to the caverns, often wading chest-deep in guano slurry—a risky proposition in a region notorious for Ebola outbreaks, he admits. Ultimately, his years of genetic testing revealed that the cave crocs exist as an entirely separate population from nearby forest dwellers. Given enough time, they could someday evolve into a distinct species. Yet their oddest attribute, their burnt orange color, wasn’t a product of their genes. Abanda’s crocs so thoroughly marinate in acidic guano, Shirley suspects, that their hides effectively get tanned.

Still, the crocs were clearly flourishing—but how? When Shirley pumped the stomachs of live crocs, he found many packed with bat carcasses. During one visit, Shirley discovered that bats pouring from the caves at dusk often got tangled up and fell to the floor, where crocodiles seized them. Occasionally, the crocs even leaped into the air to snatch a meal: further testament to their adaptability. “They found obviously a very abundant food supply, and then they just decided to stay,” Shirley says. 

Outside of Abanda, another story is unfolding. Every year, commercial hunters ship tens of thousands of dwarf crocs from remote forests to Africa’s cities for consumption, and researchers have documented instances of smuggling to Europe and North America. Even worse, adds Emmanuel Amoah, a Ghanaian conservation biologist, is habitat loss from deforestation, agriculture, and mining, which has left many populations “highly depleted.”

Precisely how depleted, though, isn’t clear. Survey methods for other, larger crocodilians, like scanning waterways at night for shining eyes, don’t apply to dwarf crocs, which are as happy in tiny wetlands as in big rivers. To get a better handle on their numbers, Shirley’s team has pioneered new methods for surveying them, including counting the reptiles along transects, or straight lines paced through the forest, a technique long applied to large mammals like elephants but never before used to count crocs. These surveys have revealed that some populations in the Republic of the Congo are so abundant that they’ve managed to sustain heavy hunting.  

Shirley has learned much from Congolese crocodile hunters, who in recent years have helped him monitor their trade to improve its long-term sustainability. His team has paired with scientists from Wildlife Conservation Society Congo to count croc harvests in villages and follow hunters on their forays, outfitting them with GPS units to better understand the industry. The group hopes to eventually help the government institute a permitting system that would limit the total catch and have hunters sell directly to markets rather than through middlemen, allowing harvesters to receive fairer value for nabbing fewer reptiles. Although the program hasn’t yet launched, Shirley says it could provide sustainable livelihoods for many in these communities.

Indeed, if these little crocs have a future, it’s because of how much they matter to humans. Not long ago, Shirley met an elderly woman who was preparing to embark on a two-week-long boat journey to Brazzaville, Congo’s capital, to bring live dwarf crocs to urban relatives who’d never tried their meat—a form of love in its own right. “Species that are important to people in one way, shape, or form,” Shirley says, “tend to be the ones that we can really work on conserving, because people care.” Even about the tiniest crocs.