Ah, man.
Today’s question is pretty gross.
Let’s give it a go: Have you ever washed
a car just to have a bird poop on it a few
minutes later?
It’s sad when you think about it.
Despite the wealth of technological and social
innovations across the span of human history,
we still can’t stop birds from flying around,
crapping on whatever they want, anywhere,
and at any time.
And it’s not even normal poop.
It’s white.
Sometimes with a dark spot in it.
But why?
That's today's question.
Why is bird poop white?
Well, the answer here is – it isn’t.
At least, bird poop isn’t all white.
It’s a mix of colors, and it can vary with
the species of the bird or its diet.
But there’s definitely white stuff in there.
It all comes down to streamlining.
Birds are like any other animal; they take
in food, process it for energy and excrete
waste.
However, where mammals like deer, elephants
or Bill Murray have two different excretion
systems – urine and feces – bird biology’s
all “ain’t nobody got time for that.”
Birds don’t even have separate exits for
their waste and reproductive systems – instead
of the genitalia/anus combo so popular in
the mammalian world, birds have a one-stop
shop called the cloaca.
It’s the entrance/exit point for the intestines,
urinary tract and reproductive system.
Yep.
Think about that for a second.
Birds also process the food they eat in a
different way.
We mammals break down protein and produce
nitrogenous waste, but we make it into urea,
which we dissolve into water and excrete as
urine.
This takes a lot of water, which means we
have to drink a lot of it – and also means
we don’t do well in places without much
water.
Birds take a different approach, and one that
conserves water.
Instead of dissolving that waste into urine,
they primarily excrete something called uric
acid – a solid, pasty junk.
That’s the white stuff you saw on your Camry
earlier.
In a way, birds aren’t just pooping on our
cars, statues, buildings and occasionally
very unlucky people looking up with their
mouths open.
They’re also peeing.
And here’s why – remember how earlier
I mentioned this was all about streamlining?
Birds aren’t trying to conserve water out
of some strange sense of environmental responsibility
– they’ve evolved to reduce their weight,
and carrying all that extra water around to
produce urine just doesn’t make sense.
And there you have it – possibly one of
the grossest questions I’ve ever had to
answer on this show.
Anyhow, thanks for watching.
Do you like birds, or have a favorite one?
I’m partial to corvids, myself – they’re
freakishly intelligent.
Let me know in the comments, and stay tuned
for more BrainStuff.
