More than 5,000 years ago, burrowing bees opportunistically colonized the skeletons of extinct rodents and sloths in a Caribbean cave. The discovery, detailed in a recent study, offers a rare glimpse into ancient insect behavior and highlights how animals adapt to unusual nesting environments. The findings also underscore the fragility of paleontological sites, as the cave itself nearly became a sewage storage facility.
Fossil Nests Found in Hispaniola Cave
Researchers excavating a cave on Hispaniola (modern-day Dominican Republic and Haiti) uncovered fossilized bee nests built inside the tooth cavities and vertebrae of rodent bones. The bees, identified as Osnidum almontei, apparently selected these cavities for their ideal size and structural stability. Most of the bones came from hutias—large, beaver-like rodents—with a few remains belonging to an extinct species of sloth.
This is the first time bee nests have been found inside preexisting fossil structures, though scientists previously documented bees drilling into bones. The new discovery suggests that bees weren’t just capable of creating nests in bones, but actively sought out existing cavities, a behavior that highlights their adaptability.
Rodent Bones as a Bee Habitat
The rodent bones accumulated in the cave over centuries, discarded by now-extinct Hispaniolan barn owls (Tyto ostologa ). These owls would transport entire hutias into the cave, either as prey or in regurgitated pellets, leaving behind skeletal remains. Over time, sediment buried the bones, creating a unique substrate for burrowing bees.
The bees weren’t the first to take advantage of the bones, as generations nested in the same cavities after previous occupants left. This suggests the site offered a reliable, long-term nesting opportunity. The cave environment itself may have played a role, as the surrounding karst terrain lacked suitable soil for burrowing. The bees adapted to the available environment, rather than creating their own.
A Race Against Development
The research team nearly lost the site to industrial development. Plans were filed to convert the cave into a septic tank, prompting an urgent “rescue mission” to excavate as many fossils as possible. Fortunately, the septic tank project was abandoned, but the incident underscores the constant threat to paleontological sites.
“We had to go on a rescue mission and get as many fossils out as possible.” – Lazaro Viñola Lopez, paleobiologist at the Field Museum of Natural History
The team has only begun to analyze the recovered fossils, promising further discoveries about the cave’s ancient ecosystem. The ongoing research confirms the value of preserving such sites, even in the face of economic pressures.
The bees’ unusual nesting habits and the cave’s near-destruction serve as a reminder that seemingly insignificant locations can hold extraordinary scientific value. The study highlights the interconnectedness of ancient life and the importance of proactive preservation efforts.
