Buzz
Nature is full of fascinating mimics, such as orchids that resemble fuzzy bees and slow lorises that imitate cobras. These adaptations serve clear purposes: orchids attract pollinators, while the cobra disguise helps slow lorises survive. Among these, the binturong stands out with a territorial scent that strikingly mimics the smell of buttered popcorn. While trivia enthusiasts have long been amused by this fact, scientists were puzzled. Recently, researchers have uncovered the mechanism behind this unique scent, though its purpose remains unclear. Their findings were published in the journal The Science of Nature.
The binturong (Arctictis binturong), commonly called the bearcat, is a resourceful member of the viverrid family. These robust animals inhabit the forests of South and Southeast Asia, growing over 3 feet in length. To mark their territory, binturongs urinate on the ground, their feet, and their tails. They then use their urine-soaked tails to spread their distinctive popcorn-like scent on trees as they move through their habitat.
Previous attempts to pinpoint the chemical compounds responsible for the bearcats' buttery scent had failed. Evolutionary anthropologist Christine Drea and her team took on the challenge once more. They gathered urine samples from 33 captive bearcats (13 females and 20 males) at a wildlife sanctuary in North Carolina. Using gas chromatography, a method that identifies and quantifies chemical components, they analyzed the samples to uncover the mystery.
Analysis of the bearcats' urine revealed 29 distinct chemicals, with each sample being unique. However, one compound, 2-acetyl-1-pyrroline (2-AP), was present in every sample. This chemical is the same one that gives buttered popcorn its signature aroma. In other words, binturong urine doesn’t just resemble the smell of buttered popcorn—it is the smell of buttered popcorn.
The discovery of 2-AP, however, led to further mysteries. This compound is also found in the scents of cooked rice and toasted bread. Interestingly, all three aromas are associated with cooking, raising questions about how this chemical is produced naturally.
"To create this compound artificially, you’d need temperatures higher than what most animals can produce biologically," Drea explained. "So, how does this animal generate a cooking-like scent without actually cooking?"
Initially, the researchers suspected that the 2-AP might not originate from the binturongs themselves but from their diet, specifically the processed Iams Chunks kibble they were fed. However, testing the kibble showed no presence of 2-AP, ruling out this possibility.
The leading theory is that the bearcats aren’t directly producing the cooked-smelling chemicals—their gut bacteria are. Studies have shown that a common bacterium, Bacillus cereus, can produce 2-AP through fermentation.
