Hello Tweeters,

Bill asked about bird poop.

Birds and mammals need to get rid of nitorgenous waste that is created
through the metabolic processes. Birds do not make urine the way that
mammals do. Mammal kidneys get rid of nitorgenous waste by forming urea.
Bird kidneys get rid of it by forming uric acid. The white stuff that
you see in bird poop is uric acid. Uric acid is insoluble in water that
is why it is tough to wash off of your car. The advantage for birds to
make uric acid is that it requires much less water in your system to
form it and get rid of it. It takes lots of water to flush urea from you
system if you are a mammal. The ultimate advantage in not needing as
much water in your system is that you are much lighter. Just another
little thing that makes flight possible.

Uric acid is much more concentrated that urea, thus it has a higher
amount of nitrogen content (if I remember correctly, it is on the order
of 1000s of times more concentrated than urea). That is way it makes
good fertilizer.

The disadvantage to making uric acid (if I remember correctly) is that
bird kidneys can not process salt as well. This is why some bird that
live in marine environments have a salt gland in their noses to make up
for it.

I hope that answers your question. If anyone thinks I have my facts
wrong, please feel free to correct them.

Russell

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Russell Rogers and Mary Moore
6637 Glenwood Drive SW
Olympia WA 98512
(360) 709-9870
mailto:rrogers at halcyon.com
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"William R. Applegate" wrote:

> Fellow Tweets,
> My daughter asked me a question which I cannot answer. Perhaps some
of you
> know the explanation;
> "Why is bird poop white when the poop of other animals is brown or
black?"
> Thanks for the help.
> Bill Applegate
> applgate at whidbey.net
> Whidbey Island, WA