Camel Resource

[Force44]

Another location for Camels could be the Canary Islands.

(They were exported to the Americas accompanied by sugar canes. Apparently in the coastal desert of Peru there used to live a small population of camels originally exported from the Canary Islands)

They might have already been on the Islands before the arrival of the Spanish but the fifteenth or sixteenth century is quoted as the date of introduction in this source.

http://www.camellosafari.com/camels/camels.html

 

[Force44]

an argument for camels to provide

Camels as Food
Camel meat, milk (and sometimes blood), are important to many African diets.

Camel's milk is very rich in fat and protein. It's apparently difficult to make cheese from it, but camel yogurt is common and you can even buy camel milk chocolate. Camel milk is the closest you can get to a human mother's milk, with 10 times more iron and three times more vitamin C than cow's milk. It is antibacterial and low in lactose (Source: Huffington Post). No wonder Chad's capital has plenty of camel milk bars and herdswomen from Ethiopia and Somalia think nothing of riding a train for 12 hours to sell it in Djibouti. Unfortunately it requires a yoga master to milk a camel.

Camel meat can be tough and taste a little strong, but raw camel liver and camel stews are popular. I've only eaten meat from a freshly slaughtered baby camel, roasted at a roadside stand in Tunisia - delicious.

Camel leather is used to make shoes, saddles, bags and belts, but unless it's well treated, it has quite a pungent smell.

exerpt from http://goafrica.about.com/od/africanwildlife/ss/The-Camel-In-Africa-Camel-Facts.htm

 

[Force44]

Camels appear to be a food staple all around the borders of the Sahara.

This includes the countries of (clockwise) Morocco, Algeria, Tunesia, Libya, Egypt, Eritrea, Sudan, Chad, Niger, Mali, Mauretanina and Western Sahara.

So probably one or two additional camels could be added to the deserttiles bordering the plains between Mali and Ethiopia.

 

[The Turk]

an argument for camels to provide

Camels as Food
Camel meat, milk (and sometimes blood), are important to many African diets.

Camel's milk is very rich in fat and protein. It's apparently difficult to make cheese from it, but camel yogurt is common and you can even buy camel milk chocolate. Camel milk is the closest you can get to a human mother's milk, with 10 times more iron and three times more vitamin C than cow's milk. It is antibacterial and low in lactose (Source: Huffington Post). No wonder Chad's capital has plenty of camel milk bars and herdswomen from Ethiopia and Somalia think nothing of riding a train for 12 hours to sell it in Djibouti. Unfortunately it requires a yoga master to milk a camel.

Camel meat can be tough and taste a little strong, but raw camel liver and camel stews are popular. I've only eaten meat from a freshly slaughtered baby camel, roasted at a roadside stand in Tunisia - delicious.

Camel leather is used to make shoes, saddles, bags and belts, but unless it's well treated, it has quite a pungent smell.

exerpt from http://goafrica.about.com/od/africanwildlife/ss/The-Camel-In-Africa-Camel-Facts.htm

Camels are not food "staples". Yes, they do feed semi-nomadic peoples, but no, they are not the staple food of city dwellers (what Civ4 actually depicts). No one eats camel meat in urban centres in the Middle East (incl. North Africa). One food stand, does not a staple make (most likely the owner coming from rural Tunisia).

Production & Commerce make the most sense, as they were used as very cheap long distance transport, but also in urban transportation (moving goods for construction etc). If Horses provide production, Camels should do so just as much.

Also none of your arguments make sense for a health bonus. Camel urine, and other parts of a camel are used in medicine, but again this is restricted to semi/pastoral nomadic peoples, most of whom most likely don't have access to other food/medicine types, like urban city dwellers would.

TL;DR: Urban Dwellers & Agriculturalists (most of the population) =/= (Semi/Pastoral) Nomadic Peoples (not depicted in the game).