The Tao of Poo

Have you noticed how many scientists have an inordinate fascination for lowly things… not small creatures, but rather the …er… waste products of larger animals. Many of us can’t keep our hands off a nice, hot pile of poop. And yes, that includes people like me, who deem ourselves to be worthy of higher things, to be interested in the minds of wild animals, not their alimentary canals.


Me and some monkey poop

This is because, everything, absolutely everything, is ultimate connected to what we digest. Survival – eating! – is an even more basic instinct than reproduction.


While you may think that the only information we can get from poop is the details of the animal’s latest meal, the science of feces goes far beyond that. In my own experience, poop is extremely valuable for indicating the stress an animal is experiencing. Yes, we produce more feces when we’re stressed (our bodies just want to drop ballast, so to speak), but every bit of fecal matter also contains products of our own hormones, which are metabolized and find their way into our urine and feces. By picking up the droppings of a monkey, a mongoose, or a fox, we can determine how much cortisol was circulating in that individual’s body, how much testosterone, and quite a few other hormones. And this is incredible, because now we don’t need to capture animals – stressing them out – to draw blood for hormonal information.

This hormonal data has given us some incredible insights into animal behaviour. For example, a friend of mine discovered that gelada monkeys spontaneously abort or reabsorb fetuses back into their bodies when new males take over their harems(!). She could see this based on fecal hormone metabolites, and making detailed notes of wild gelada behaviour… I myself have seen evidence that being isolated stresses out bat-eared foxes, and my students have spent months in Prof André Ganswindt’s Endocrine Research Laboratory trying to unravel the hormones that make wild foxes tick.

Over and above the hormones, your fecal matter can give us genetic data – both your own and the DNA of millions of microbes living in your guts.  We can assess relationship networks in monkeys, and aquatic mammals without the prick of a single needle… We can investigate the communities of bacteria inhabiting your innards. And – perhaps shockingly – this intimate knowledge of the creatures you host can tell us a lot about your mental state. These miniscule creatures in your guts have even been called “mind-altering!”

Considering that most of our vertebrate study species have to poop on a regular basis,  providing us with such ample data, you would imagine that most researchers like to get their hands dirty with fecal matter. But analysing poop is still not as widespread as you’d think. A recent review by one of my students shows that almost nobody has looked at the hormones of male carnivores, which can be used to (finally!) tell us what hormonal changes fathers undergo. Maybe it’s methodological or financial constraints. But, honestly, I suspect it may just be that some of us are slow to change our long-favoured techniques, sitting with our heads up our money makers.

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