Why do binturongs smell like popcorn?

Of the 200+ species we steward here at Zoo Atlanta, binturongs are perhaps one of the least known. These adorable mammals from the family Vivvirid are also called “bearcats” (although they are not cats) and hail from Southeast Asia. Among those familiar with the species, they are known for their notably recognizable scent: buttered popcorn.

While the scent in question is unusually pleasant, the source of the scent is less than appetizing. After multiple studies, scientists in 2016 determined that the signature binturong scent originates from chemicals in their urine. Like many animals, binturongs use urine as a method of marking territory and finding mates. Binturongs urinate in a squatting position, soaking their feet and tails, which they drag behind them to leave a scent trail.

Researchers at Duke University, Hendrix College, the CDC, and the Cincinnati Zoo identified a total of 29 chemicals present in binturong urine using a technique called gas chromatography-mass spectrometry. The one chemical consistent in each sample was 2-acetyl-1-pyrroline, or 2-AP, the same chemical that forms in popcorn during the popping process when heat kickstarts reactions between sugars and amino acids in the corn kernels.

At first, this finding baffled scientists: 2-AP is usually only found in temperatures above what is physiologically possible for animals. The most likely explanation for its presence in the lower body temperature of the binturong is a chemical reaction between binturong urine and bacteria and other microorganisms present on the animal’s skin and in the gut.

This makes sense given that bacteria is also responsible for the familiar Frito or corn chip scent you may have noticed on your dog’s paws. Not to worry, however, as that scent (which I personally love) derives from the bacteria Pseudomonas and Proteus and has nothing to do with your pet having pee paws (the presence of these bacteria is totally normal and healthy).

Next time you visit the Zoo, make sure to visit the Binturong Habitat and say hello to our very own two bearcats: Baloo and Bramble. And maybe if you’re lucky (or perhaps unlucky if you think too much about it), you’ll get a whiff of warm, buttered popcorn.

 

Sources:

Hassiotis, C. (n.d.). Binturongs Smell Like Hot, Buttery Popcorn — Now We Know Why. How Stuff Works. Retrieved March 6, 2023, from https://animals.howstuffworks.com/mammals/binturong-urine-smell-hot-popcorn.html

Smith, R. A. (2016, April 13). Why Bearcats Smell Like Buttered Popcorn. Duke Today. Retrieved March 6, 2023, from https://today.duke.edu/2016/04/popcornscentedbinturong