A cenote is a natural sinkhole formed when the limestone bedrock above an underground water source collapses, exposing the groundwater below. These unique geological features are found predominantly across the Yucatán Peninsula in Mexico, which contains thousands of them. The ancient Maya viewed cenotes as sacred portals to the underworld, often building major settlements like Chichén Itzá nearby. Crocodiles can occasionally be present in these freshwater pools, but encountering one is a rare event.
The Presence of Crocodiles in Cenotes
The Yucatán Peninsula is home to two crocodile species. The American Crocodile (Crocodylus acutus) is the larger species, known for its long, slender snout and high tolerance for saltwater. The Morelet’s Crocodile (Crocodylus moreletii) is smaller, has a broader snout, and prefers freshwater swamps and inland lagoons.
Crocodiles found in cenotes are usually the Morelet’s species or smaller, juvenile American crocodiles. These reptiles are shy and secretive, often seeking refuge in mangrove roots or along the water’s edge. The cenote’s limited space and food resources generally cannot support large adult predators, meaning individuals found here are typically smaller.
Habitat Connectivity and Cenote Ecology
Crocodiles access cenotes because these pools are openings to an immense, continuous subterranean system. The Yucatán Peninsula is a porous shelf of limestone, lacking surface rivers, and instead holds the world’s longest mapped network of flooded caves and underground rivers. This vast network connects the cenotes to each other and to coastal areas like mangroves and the ocean.
The American Crocodile’s physiology allows it to move freely between these environments due to specialized salt glands on its tongue. These glands enable the species to excrete excess salt, tolerating brackish water and even venturing into the open sea. This explains why American Crocodiles are more frequently found in open cenotes near the coast, as they use the underground system to travel between saltwater and freshwater feeding grounds.
The Morelet’s Crocodile, while preferring freshwater, also uses this subterranean system to disperse and establish new territories. Cenotes are windows into this continuous underwater landscape, allowing for the occasional transit of aquatic wildlife. This movement explains why a crocodile may temporarily inhabit a cenote while moving between larger bodies of water, making the appearance incidental rather than permanent.
Assessing the Risk and Safety Measures
Crocodile encounters in cenotes are extremely uncommon, and the level of risk varies significantly depending on the cenote’s physical characteristics. Open cenotes, which are surface lakes connected to mangrove swamps or coastal lagoons, carry the highest potential for crocodile presence. Semi-open cenotes, which are partially collapsed, and fully enclosed cave cenotes, which are dark and confined, present the lowest risk. Cave cenotes are unsuitable for larger reptiles that require basking areas and easy access to the surface.
To ensure safety, visitors should always follow the guidelines posted at cenote entrances. Never swim at dawn or dusk, as these are the peak movement hours for crocodiles. Never feed any wildlife, as this encourages them to associate humans with food. Maintaining a respectful distance and checking for official signage are the most practical safety measures.