You probably keep your ID in your wallet. But where do meerkats keep theirs?

The strange and smelly world of a meerkat’s butt.

A meerkat is neither a cat, nor is it in any sense mere. Or even meer.

The name “meerkat” originated in the Afrikaans language, which has many similarities with Dutch, but the label was mistakenly attached to a creature that’s not a cat but a mongoose (which is itself, of course, not a goose – but we digress.)

You may be forgiven for imagining that one of these apparently cute creatures might make an adorable house pet, but how wrong you’d be.

How very wrong.

For a start, they can be unexpectedly aggressive, especially towards guests, and they also have a vicious bite.

There’s something much worse than this, though, and it’s bacterial.

A pet meerkat, you see, would tend to scent-mark its owner and the house, which it would view as its “territory,” and it would do so (and there really is no polite way to say this) by turning what’s known as its “anal pouch” inside out in order to rub a smelly paste on all the surrounding surfaces, household and human.

That pet meerkat is suddenly not looking quite so appealing, right?

Earlier this month, researchers from Duke University in North Carolina published a study detailing their work in the Kalahari desert, where they discovered no less than 1,000 different types of bacteria living in the paste of a meerkat’s anal pouch.

Now, if you thought you were having a hard time at work, just be very glad you weren’t one of those scientists in the Kalahari Desert swabbing the anal glands of fully conscious meerkats.

(Frankly, let’s be honest, also be very glad you weren’t one of the meerkats.)

As you might guess, there was more than idle curiosity behind this risky, and probably repugnant, research.

You see, it was observed that meerkats leave a smelly scent on surfaces as a way of warning other creatures to steer clear of their territory, with the smell being so personalized that other meerkats can tell whether it was left by a relative, rival, or potential mate.

For decades, scientists have worked with what they termed the “fermentation hypothesis,” which proposed that bacteria living in an animal’s scent glands metabolize the gland’s primary products into smelly compounds that the host then uses to communicate with others of the same species.

When the fermentation hypothesis was formulated in the 1970s, it wasn’t yet possible to properly investigate it since so many bacterial species hadn’t yet been described.

While this is still the case, we are at least getting there thanks to the same kinds of advanced DNA sequencing technologies that we use here at uBiome to investigate the human microbiome.

The Duke University scientists were able to analyze the gene sequences of bacterial samples swabbed from the meerkats’ rear ends (what you might call their meerkrobiome, perhaps), and they also subjected the samples to gas chromatography mass spectrometry, every bit as complicated as it sounds.

In simple terms, however, this process enables complicated chemical mixtures to be separated, identified, and then quantified.

And, boy, were those samples “complicated chemical mixtures,” being made up of scented liquid that oozes out of glands in a meerkat’s anus, good old feces, and debris picked up from the environment.

This debris includes sand, which, as you may suspect, is in plentiful supply in the Kalahari.

It was the combination of sequencing and gas chromatography that revealed the 1,000 types of bacteria, along with over 200 volatile compounds, including carboxylic acids, in meerkat pouch paste.

Carboxylic acids are widely found in nature and are often known for producing foul stinks.

One, butanoic acid, is the main ingredient in stale sweat, for example.

Dr. Christine Drea, a professor of evolutionary anthropology, was one of the Duke University report’s co-authors.

Noting that meerkats are not the only animals to use scent to communicate – hyenas, badgers, bats, and elephants do so too – Dr. Drea explained that even humans unwittingly participate in this behavior.

“Virtually all of the telltale odors in human armpits come from bacteria,” she said. “They don’t just make us stink – the odors they give off help us distinguish kin from strangers, and choose among mates.”

So, to a long list of things to be grateful for today, we should perhaps add the following.

Being able to achieve signalling of this kind, using only slightly whiffy armpits, rather than requiring an anal pouch, is clearly a considerable cause for celebration.

On top of that, not needing to have an anal pouch that you’re expected to turn inside out is surely reason for those celebrations to turn into a veritable skyful of Independence Day-style fireworks.

Happy Fourth of July. To you, and all meerkats.

More reading

Bacterial communities in meerkat anal scent secretions vary with host sex, age, and group membership


Meerkats Can Thank Bacteria for Their Signature Butt Scents

Meerkats use bacteria from their butts to make stinky graffiti

Smell you later. Meerkats use scents stored in a pouch under their tail to mark their territory.

Social odours covary with bacterial community in the anal secretions of wild meerkats