# Why is bird poop white? **URL:** \ **Category:** Factual Questions\ **Created:** [December 1, 2005, 3:17am UTC](https://boards.straightdope.com/t/why-is-bird-poop-white/333509 "2005-12-01T03:17:06Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![DaveRaver](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/daveraver/32/1078_2.png) [@DaveRaver](https://boards.straightdope.com/u/DaveRaver)\ **Post date:** [December 1, 2005, 3:17am UTC](https://boards.straightdope.com/t/why-is-bird-poop-white/333509/1 "2005-12-01T03:17:06Z")
If dead red blood cells make our poop brown, what makes bird poop white? (unless of course they are pooping on a white car in which case they poop black!) ---
**Author:** ![nonacetone](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nonacetone/32/2819_2.png) [@nonacetone](https://boards.straightdope.com/u/nonacetone)\ **Post date:** [December 1, 2005, 3:31am UTC](https://boards.straightdope.com/t/why-is-bird-poop-white/333509/2 "2005-12-01T03:31:00Z")
It can also be a nasty purple color when they eat the damn mulberrys. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [December 1, 2005, 3:50am UTC](https://boards.straightdope.com/t/why-is-bird-poop-white/333509/3 "2005-12-01T03:50:05Z")
Short, simple and slightly inaccurate answer is that bird shit is white because it isn’t just shit, it’s a mixture of shit and piss. Bird piss is white, hence the pile of white stuff on bird shit is actually dried piss. Longer and more accurate answer. Birdies come from eggs. A chick in an egg can’t produce liquod waste because that would rapidly diffuse through the entire egg and poison the chick. As a solution bird kidneys don’t produce liquid urea waste as mammals do. Instead they convert the urea into uric acid. Uric acid is a white crystalline solid. That explains what the white stuff is. Add to this that birds don’t have an anus and a separate penis/vagina as in most mammals. Instead the kidneys and bowel both void through a common opening known as a cloaca. So when a bird takes a crap it also releases the waste from the kidneys. As a result bird shit can be almost any colour at all, but it will almost always have a little pile of white crystals lying on top. ---
**Author:** ![Duckster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/duckster/32/1244_2.png) [@Duckster](https://boards.straightdope.com/u/Duckster)\ **Post date:** [December 1, 2005, 4:21am UTC](https://boards.straightdope.com/t/why-is-bird-poop-white/333509/4 "2005-12-01T04:21:11Z")
> [@](#): > > Unlike mammals, birds don’t urinate. Their kidneys extract nitrogenous wastes from the bloodstream, but instead of excreting it as urea dissolved in urine as we do, they excrete it in the form of uric acid. Uric acid has a very low solubility in water, so it emerges as a white paste. This material, as well as the output of the intestines, emerges from the bird’s cloaca. The cloaca is a multi-purpose hole for birds: their wastes come out of it, they have sex by putting their cloacas together, and females lay eggs out of it. Source: [http://www.heptune.com/poop.html](http://www.heptune.com/poop.html) ---
**Author:** ![Freddy\_the\_Pig](https://avatars.discourse-cdn.com/v4/letter/f/a587f6/32.png) [@Freddy\_the\_Pig](https://boards.straightdope.com/u/Freddy_the_Pig)\ **Post date:** [December 1, 2005, 4:43am UTC](https://boards.straightdope.com/t/why-is-bird-poop-white/333509/5 "2005-12-01T04:43:50Z")
What about Canada geese? Their all-too-familiar turds are sort of dark green, which I suppose makes sense considering that they eat grass. But the turds are kind of watery and don’t seem to include any paste. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [December 1, 2005, 4:53am UTC](https://boards.straightdope.com/t/why-is-bird-poop-white/333509/6 "2005-12-01T04:53:19Z")
Low protein diet. Nitrogenous wastes such as urea and uric acid are primarily the result of the animal eating so much protein that it starts burning protein as food rather than using it as building material. Geese and other birds on a diet of low quality vegetable matter are often struggling to get enough protein, and so produce relatively little uric acid. Birds on a grain diet recieve adequate protein and so produce modest amounts of white crap. The shit of carnivores or seabirds has huge amounts of white crap all over it. ---
**Author:** ![Fridgemagnet](https://avatars.discourse-cdn.com/v4/letter/f/22d042/32.png) [@Fridgemagnet](https://boards.straightdope.com/u/Fridgemagnet)\ **Post date:** [December 1, 2005, 1:56pm UTC](https://boards.straightdope.com/t/why-is-bird-poop-white/333509/7 "2005-12-01T13:56:38Z")
What **Blake** said; just to add this old joke (courtesy of Kurt Vonnegut): Q. What’s the black stuff in the middle of bird shit? A. That’s bird shit also. OK, not that funny. Or even technically correct.