|Do birds urinate?|
|Question Date: 2014-04-16|
This is interesting, and has to do with the
basic "plumbing" of animals. Humans and many other
animals have separate solid and liquid waste.
Solid waste is the unprocessed remains of food
through the digestive tract. Liquid waste, or
urine, is waste that has been filtered out of the
blood to regulate the chemicals that are in blood
and keep you healthy. These two separate sources
mean that there is no "separation" of liquid and
solid waste, since they come from different places
anyway, and it makes good sense that they leave
the body separately.
Now that we know about people plumbing, do birds
urinate? The answer is yes and no. In birds, both
liquid and solid waste leave the cloaca (located
on the butt). Birds have a urinary tract, but it
is combined with solid waste before being
released. So, birds urinate, but it is mixed with
solid waste and removed at the same time. Having
only one system for releasing weight may make
birds lighter, and make flying easier.
That's a great question! Birds don't urinate.
Flying requires a lot of energy, so birds have
evolved to be as light as possible. Having urine
means holding water, which is heavy, and makes
flying more difficult. It doesn't make sense to
carry around all that extra weight of water.
Instead birds get rid of their waste through their
poop. Urine in humans and other mammals contains
urea, which is how we get rid of nitrogen in the
body. Birds also need to get rid of nitrogen, so
instead of urea, they make uric acid, which they
get rid of in their poop. It takes a lot more
energy to make uric acid than urea (which is why
mammals don't make it), but it requires much less
energy than trying to fly with all the extra
water. The uric acid is slightly corrosive, which
is why you should immediately clean bird poop off
Sort of. Birds excrete urea, which is the main
chemical in urine, but they suck the water out of
it, so they excrete it as a solid instead of as a
Yes, they do urinate, but it is much different
than how humans urinate.
In humans, waste flows into tubes called
ureters and is then carried into the bladder for
storage or release. We produce urine which
contains salts and other materials our bodies
don't need. Some of those materials are uric acid
and urea which are toxic to our bodies. We have
two openings to get rid of waste: one for fluid
waste and one for solid waste.
Now, birds only have one opening to get rid
of their waste and they do not have a bladder.
Their opening is called a cloaca; this is where
their waste and eggs with baby birds come out
from. They absorb a lot of the water back from
their waste so their "urine" containing uric acid
comes out in a white crystalline form with their
Birds actually combine their solid and liquid
waste into a white paste with varying amount of
green/brown color. The white part is mainly
comprised of uric acid and the green/brownish
parts are comprised of fecal matter.
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