Why is bird shit white?
"birds, unlike mammals, don’t produce urine. Instead they excrete nitrogenous wastes in the form of uric acid, which emerges as a white paste. And uric acid doesn’t dissolve in water easily. Hence its ability to stick to your windshield like blobs of white plaster." Audubon
Well there's your answer from Audubon and I don't think I can really add anything to the question of why. Other than in answer to the other question why? - Why am I writing about this? Well yesterday on my walk as I was looking down - you remember I mostly look down - I noticed in a couple of spots a lot of bird shit - or poo - whichever you prefer. It was a rather lovely abstract sort of painting in a way, but that's not really what I thought about. The question in my head was - why is it white? All the other poo I can think of is brownish. So what's so special about birds? And bird poo is special is it not? It's fertiliser.
So nothing more about why it's white - that's at the top of the page - but perhaps a little bit about its uses. We'll see where it goes.
Having done my 'research' I now have a selection of quite interesting things - many of which I did not know. It's all a bit random but nevertheless interesting - and it's appropriate for a food blog because, as we know, bird poo is excellent fertiliser. Think chickens if nothing else.
First of all - another reason the bird poo is white is that it all comes from the same hole or orifice to be more technical.
"both sexes have a cloaca — an all-purpose entrance and exit for the intestinal, reproductive, and urinary tracts. It’s used to expel waste, lay eggs and have sex (which, for birds, happens in the form of a “cloacal kiss”). This orificial multitasking explains the dark bullseye that’s often in the center of the white acid waste. That’s the actual “poop” part, or stool. Because the acid and poop are expelled at the same time from the same opening, but from two different bodily systems, they don’t have much time to blend, and you get a bird dropping with two distinct parts that looks like a poor man’s Rorschach test." Mental Floss
Bet you didn't know that.
There seemed to be a lot of focus on cars in the articles I found. I guess it's because it tends to fall on windscreens, thus blinding you, or because it's not good for the car - the acid is very bad for it. And apparently: "A study in England found that red cars are most likely to be the target of bird droppings!" Bird Note Which is a bit sad because red cars are fun and also are rather more visible than most colours. Which is good for safety.
Such has been the value of bird poo in the past that wars have been fought over it and strict laws put in place as to who could exploit it. The following sums up a whole lot of things about the world in general really. It's from an excellent article on Atlas Obscura about guano - the most famous kind of bird poo.
"A new natural fuel is discovered. It’s so efficient, the initial science is unbelievable; so powerful, it revolutionizes an entire industry. Deposit-holding countries get rich. Businessmen and speculators get richer. Laborers muscle it right out of the ground, and ships carry it around the world, where it helps to power every life, every day.
Soon, demand far outstrips supply. As reserves dwindle, world powers grab at the last of the stuff. Unprecedented legislation is passed; questionable diplomatic decisions are made. Remote locations host power struggles. Whole countries go to war. And then what?" Cara Gaimo - Atlas Obscura
The history of Nauru in particular is an example of this and there is another excellent article about it - this time on Beachcomber's Bizarre History Blog. From rags to riches to rags again basically, with conquests and power struggles galore in between. And it's so tiny! - 8 miles square!
This article does talk about Nauru being an island of Guano, but according to Wikipedia it has actually been found that this is not so:
"High-grade rock phosphate deposits on Nauru, Banaba Island, Christmas Island (Indian Ocean) and other raised atolls, long supposed to derive from bird guano, have more recently been considered the result of marine sedimentation" Wikipedia
Which might mean that it was originally bird poo anyway. Whatever the reason there is none left. Though with guano in some parts of the world the value of the product has meant that the bird species that produce it have come to be protected.
Guano is a particular kind of bird poo - from sea birds and from bats, with this cormorant being the bird that provides most of it.
Peru has historically been the main provider. Wars were fought there too, and today the economy has collapsed because it's all gone. And besides nowadays such fertiliser can be and is produced in the lab.
Mind you with a revival in organic food there has come an increased demand for a 'natural' product and I found at least one Australian company Madura Guano Gold, that mines it in Indonesia - in this case from bats I think.
For "guano is a highly effective fertilizer due to its exceptionally high content of nitrogen, phosphate and potassium: nutrients essential for plant growth." Wikipedia
The Incas of Peru used it well over a thousand years ago to fertilise their fields.
“in the times of the Inca kings, each town was assigned its own island, and each household a share of that island, according to need. Anyone who messed with this system, harmed a seabird, or so much as landed on a guano island during breeding season was subject to execution." Garcilaso del la Vega 1609
In America they passed legislation allowing people who discovered a guano island to own it for themselves. Some of these are tiny. Here is one off Mexico.
And here's another surprising little fact, gleaned from Wikipedia and confirming the influence on world events that guano has had over the years.
"DNA testing has suggested that new potato varieties imported alongside Peruvian seabird guano in 1842 brought a virulent strain of potato blight that began the Irish Potato Famine" Wikipedia
And we all know what effect the potato famine had on the distribution of the Irish around the world and the depopulation of Ireland itself.
I even found that one research project, endorsed by publication in Nature magazine, is that in the Arctic the ammonia arising from the guano of the seabirds there, produces clouds that may protect the earth from climate change. Well only in a temporary and local sense I guess, but still.
Then there's chicken manure - another time. Not to mention pigeon poo which, I gather is very popular in England.
And one last thing:
"Japanese Nightingale poop is mixed with rice bran and water and used to exfoliate the skin." Mental Floss
It's an ancient Geisha thing but still in use today.
All from seeing pretty patterns in bird shit on my walk. Like I said - a bit random and bitty but interesting I hope.
