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Poop, well, kinda stinks.
And when it’s stuck to the bottom of your shoe,
it might not occur to you to be grateful for the opportunity.
But some researchers happen to like poo. Or more specifically, the stuff in it.
Because it has a lot of stories to tell about the natural world if
you know how to read them.
I’m not just talking about what an animal was munching on.
Poop can tell us about everything from who an animal’s hanging out with,
to how likely it is to have babies.
All you have to do is be willing to look very, very closely at some animal droppings.
Poop has some pretty great advantages when it comes to
studying animals in the wild.
Researchers can swoop in and take the sample
without needing to get too close to the animal.
Basically, it’s a way to avoid bothering them too much.
One way to glean information from animal poop is by
looking at the hormones it contains.
These molecules are used to signal information throughout the body.
For example, glucocorticoid levels shoot up when animals deal with stressful
events like severe weather, being around predators, or being harassed by people.
In a 2017 study, researchers extracted this hormone from
Cape Mountain zebra droppings.
That let them see how stressed out the animals were at different times of the year,
and under different social and environmental conditions.
For example, in the spring, before the summer rains,
the zebra’s glucocorticoid levels were high.
They were even higher for zebra living in areas with lower quality grass.
The zebra were chronically stressed out from their poor diets.
The same study also looked at the levels of the
hormone testosterone in male zebra poop.
In areas with more non-breeding males than females, the male zebra in herds had
higher testosterone levels.
Herds have one stallion who breeds with the mares in the herd,
and all the other stallions form their own “bachelor” groups.
So the researchers think the higher testosterone levels may be related
to more inter-male competition.
And that’s not a great thing.
See, the scientists noticed that when testosterone levels were higher,
the females’ ability to produce offspring was lower,
although they don’t know why that’s the case yet.
Overall, poop hormones came in useful for understanding
why a population of animals might be struggling.
And that gives conservationists some tools to help them.
But poop research goes beyond just hormones.
Animals’ guts are alive with the bacteria that help them
digest food -their microbiome.
And exactly which microbes are kicking around in there can
provide a lot of information.
To figure out exactly what’s in the poop,
researchers often use a technique called metagenomics.
It’s essentially grabbing the genetic material from lots of different microbes
in a sample all at the same time.
In a 2021 study, researchers analyzed fecal samples from griffon vultures in an
effort to figure out how they can digest rotting carrion without getting sick.
And it seems like the vultures might get by with a little help
from some microbial friends.
The researchers identified nearly 700 enzymes made
by the vultures’ gut microbes.
Those enzymes were found to break down toxins in their food.
We’re talking nasty stuff like Staphylococcal enterotoxin E or AB5 toxins.
In humans, those can cause food poisoning and lead to the symptoms of
cholera and whooping cough.
The researchers then made 15 of those enzymes in the lab so they could test
if they actually do break down the toxins.
They put those enzymes on a fancy chip together with pieces of the proteins from
the toxic substances in carrion, and then monitored the results
as the enzymes broke them down. And this approach of looking at
all the bacteria together helped them paint a
bigger picture than chasing down species of bacteria one by one.
Poop can even tell us about the social structure of the animals that pooped it.
In a 2015 study, researchers were able to sort 48 baboons into two different troops
living in different parts of the savanna.
They did so by looking at the type and number of bacteria
in each individual’s poop.
But that wasn’t a function of what they were eating.
Instead, it depended on which baboon was grooming whom.
See, baboons who spent more time grooming each other
had more similar gut bacteria.
The researchers suggest that might be because the animals are transferring
bacteria from the groomee to their mouths when they go to
lick their hand in between grooming bouts.
Pretty gross, but in fairness, baboons don’t have sinks.
But it does mean that the closer the individuals are to one another,
the more often they interact with each other and the more often they swap stomach
residents, leaving a trail for the researchers to untangle.
This kind of research is so widespread that one group of scientists
have created a poop database to reference.
The database contains the genomes of more than 1,200 bacteria
found in the poop of more than 180 different species from all over the world.
The scientists who developed the database hope it will be used to better
understand the ecology of different animals,
and to keep an eye on potential disease-causing microbes.
Poop is a humble resource, but a powerful one,
in our efforts to help conserve animals and their habitats.
And it’s all thanks to what they leave behind.
Thanks for watching this episode of SciShow,
and thanks to this month’s President of Science, Matthew Brant!
Your support means a lot to us, and it truly makes these videos possible.
If you’d like to support us too, you can get started at patreon.com/scishow.
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