I’m wandering around the Reptile House of the Smithsonian Zoo in Washington D.C. The smell is strange — it’s not like the Great Ape House, which literally smells like a bunch of monkeys. Instead, the smell is quite faint. If I could describe it in one word: Scaly.
As I walk around, I take a look into the exhibits of the usual suspects: The Burmese rock python, the American alligator, and of course, who could forget the Eastern red-backed salamander? But that’s when it hits me — the faint, almost nonexistent smell of the reptiles and amphibians is being overpowered by a strong, aromatic scent. It’s coming from directly behind me, and I think I know exactly what it is…
“Binturong?!” is the first thought that jumps into my mind. I turn around, and instead of a binturong, I find a man eating popcorn. I silently laugh to myself, as I continue along the exhibit. Why would there be a mammal in the Reptile House?
What is a binturong?
Perhaps at this point you are wondering: “What the heck is a binturong?” A binturong (Arctictis binturong), also known as a bearcat, is neither a bear nor a cat. Instead, binturongs are viverrids, so they are closely related to fossas and civets. Binturongs are omnivores native to the tropical forests of southeast Asia, mainly eating fruits and berries as well as occasionally hunting small animals and insects.
Binturongs are medium-sized mammals, weighing anywhere from 11 to 36 kilograms and measuring 0.6–0.9 meters in length, excluding their tail. Their tails are nearly as long as their bodies. Female binturongs are, on average, 20% larger than their male counterparts and also give birth to two offspring at a time, called binlets (this name is far too cute to feel very scientific).
These furry creatures are also equipped with prehensile tails, which they use like a fifth limb to grip onto the tree branches of their arboreal habitat. Although I did mention that binturongs are omnivorous by diet, they technically belong to the order Carnivora, and therefore, constitute one of the two carnivores that have a prehensile tail, the other being the kinkajou.
Binturongs are considered to be a vulnerable species on the IUCN red list, meaning they are just one level above being endangered. Their population is declining, mainly due to habitat destruction, but also because of poaching for traditional Asian medicines (which don’t work) and exotic fur/pet trade.
They smell like… what?
As stated earlier, binturongs have a natural odor that smells of buttered popcorn, something that’s definitely not very common in the animal kingdom. How is this possible?
The chemical compound that gives freshly popped popcorn its smell, 2-acetyl-1-pyrroline, or 2-AP, is also found in the urine produced by binturongs. Since binturongs are mostly solitary animals that do not live in groups like wolves or lions, they use their popcorn scent to let others of their species know where their territory is.
Interestingly enough, we don’t know for sure why binturongs smell like popcorn, since their urine on its own does not smell like popcorn. 2-AP is also found in other cooked foods like toast or rice, but the way that 2-AP is given off by such foods is via a reaction that shouldn’t be possible by means of the binturong.
The Maillard reaction is what causes your toast or steak to give off their attractive aromas. This reaction occurs between amino acids and reducing sugars to create a new mixture of polymerized proteins and brown pigments known as melanoidins. The Maillard reaction occurs due to the high temperatures associated with cooking, which is usually produced by flames, electric stovetops, etc. So how does the binturong achieve this? They aren’t being heated up to hundreds of degrees to achieve the Maillard reaction (at least I hope not, that sounds painful).
Perhaps binturongs ingest 2-AP in some form through their diet. This would be the same logic that applies to asparagus making our urine smell particularly rotten. However, binturongs don’t ingest any cooked food, and even in captivity, only ingest one cooked food item: Binturong kibble, which is completely devoid of 2-AP.
The most likely explanation for binturongs smelling like popcorn is that 2-AP is created when their urine comes into contact with microbes that live on their skin and fur. When binturongs pee, they do so in a squatting fashion. This causes their urine to soak their feet and tails, the parts of their body that drag along tree branches and trunks. This is how they mark their territory, and very likely, is how they end up smelling like popcorn.
In the same way that bacteria can create smells by breaking down sweat on our bodies, microorganisms that live on the skin and fur of binturongs could break down their urine to produce the scent that we recognize as popcorn.
Where there’s popcorn, there are binturongs
Though I was very disappointed to find a man eating popcorn rather than a binturong, I shouldn’t have been too surprised. After all, I was in the Reptile House, where a binturong does not belong (sorry for rapping on you).
Dejected, I walked out of the Reptile House to look at other exhibits. As I wandered around, I, very appropriately, ran into a popcorn stand. Seeing those puffy, yellow snacks and breathing in their intoxicating aroma only further reminded me of the animal that had eluded me earlier. I was determined to find a binturong.
With my head held high and my spirits up, I searched far and wide, looking under benches, lifting trash can lids, and even the men’s restroom. After many eons of searching, there was no sign of the furry creature that I sought. I became so desperate that when a mother passed by with a full cover stroller, I violently lunged toward her, tearing open the stroller’s canopy and plucking out whatever was inside, hoping that it might just be a binturong.
To my disappointment, I held a human infant in my hands, not a binturong. That’s when I remembered that I was in a zoo. Maybe I should have been looking in exhibits this whole time.
“Silly me.” I chortled, as I tossed the newborn over my shoulder. I dashed off to the nearest exhibit, and lo and behold, my eyes set upon the most magnificent creature to ever grace this good Earth. It was a binturong.
Curled up on a small platform atop a tree, a surprisingly large black mound of fur laid sleeping. Its head was tucked away, facing opposite of me and its prehensile tail served as somewhat of a thin blanket laid over its body as it rested peacefully. It was a beautiful sight.
As I inhaled through my nostrils, I expected to get a strong odor of buttered popcorn, only to find… Nothing.
“Is my nose working?” I wondered out loud. Several passerby turned their heads, confused as to why there was someone sniffing one of the zoo animals and asking strange questions to no one in particular.
I inhaled again through my nose, and yet again, smelled nothing. Perhaps my nostrils were clogged that day, or maybe the air was simply too cold for the binturong’s odor to be strong enough. No matter what it might have been, I walked away having learned a life lesson that day about expectations and what you are searching for. It is difficult for me to put it into an explanation, so I will leave you with this haiku:
Binturongs are cool
Their scent should smell like popcorn
If they are to pee
Disclaimer: No infants were harmed during the production of this story.