So what are Camel humps filled with?
It turns out, fat.
These fat humps can weigh as much as 80 pounds and allow the Camel to comfortably go one
to two weeks without eating, if necessary.
Now, some of you out there might be saying to yourselves, “Well, but 1 gram of fat
actually gets converted to more than 1 gram of water during the metabolic process, so
it actually is a kind of water store.”
This is correct in principle, but ends up not helping the Camel out any in terms of
water supply.
Even though more water is produced processing the fat than there was fat, gram for gram,
the metabolic process actually uses quite a bit of water due to the arid conditions
Camels live in.
Basically, they lose a lot of water through their lungs getting the oxygen necessary to
process the fat.
So the net effect of processing the fat actually results in less water than there was before.
So where do the Camels store extra water?
It turns out, mostly in their blood and other places there are already fluids in their body.
There really is no central water store anywhere in a Camel.
What allows a Camel to survive in desert environments is mainly just that they are incredibly efficient
with their water usage.
In fact, they are so efficient, that in milder climates a Camel can get all the water they
need just from eating relatively green plant life.
Their bodies conserve water in just about every way imaginable.
For instance, when they pee, their urine contains very little water, being more of a pasty substance
that has approximately the consistency of syrup.
On the other end of things, their feces comes out almost completely dried out and can be
used right away by humans for making fires or the like.
For comparison, human fecal matter typically is made up of about 75% water.
A major area most animals lose water, particularly in arid environments, is by breathing.
Camels are no exception, but their breathing system is much more efficient than most.
Their nostrils have a mechanism for trapping moisture in their breath before it is exhaled.
This moisture is then returned to their bodily fluids.
The other major area most mammals lose water in hot areas is through sweat.
It turns out, Camels don’t need to sweat very much to stay cool.
There are a few things that go into this, most impressive of which is that their body
temperatures can comfortably range from about 93 degrees Fahrenheit to 106 degrees Fahrenheit
without any real negative side effects.
Their bodies are also well equipped for keeping heat out (for more on this see the Bonus Factoids
section below).
After a cool desert night, their body temperature will be around 93 degree Fahrenheit.
Given their large size and their body’s ability to keep heat out, it ends up taking
a while for their temperature to rise to closer to the 106 degree Fahrenheit level.
So in some cases, the Camel may not need to sweat at all during a given day, depending
on the ambient temperature and how hard they are working.
However, if they do get close to that 106 degree Fahrenheit threshold, their sweat mechanism
will kick in.
Like the rest of their body when it comes to water usage, their sweat mechanism is as
efficient as sweating can be, with the sweat evaporating at the skin surface level rather
than soaking into their hair and wasting some of the cooling effect in evaporating off that
hair.
Another interesting thing is how a Camel’s body actually manages water internally.
When they need water, their body will first get the water from all fluid parts of their
body except the bloodstream.
This allows their blood to continue to flow normally, even when they are relatively dehydrated.
They can withstand up to a 25% weight decrease from water loss and it isn’t until they
start getting close to that level that their main store of water in their blood starts
to get used.
For comparison on how impressive that 25% number is, most mammals will experience cardiac
failure around 12-15% weight decrease due to water loss.
This all adds up to a Camel that isn’t carrying any extra weight being able to go around two
to three weeks in a desert environment without needing to drink water.
On the other hand, if the Camel is being used as a pack Camel and is carrying a lot of weight,
they can go three or four days in that environment without needing to take in any water.
A Camel’s blood cells also have some unique properties among mammals.
The blood cells are in the shape of elongated ovals, instead of round, which allows them
to flow more freely when the Camel is dehydrated.
The blood cells are also able to handle large swings in water levels without rupturing,
which is essential for the blood stream’s ability to store extra water.
Camels have three eyelids.
Two of the eyelids have eye lashes which help protect their eyes from sand.
The third is a very thin lid which works as a sort of “windshield wiper” to clean
off their eyes.
It closes/opens from side to side rather than up and down.
It is also thin enough that the Camels can see through it somewhat.
So in a sandstorm or otherwise windy day where sand is being stirred up, they can close that
lid to protect their eyes from the sand, but still see where they are going.