The camelids, as a family, include the "New World" camelids: thellama, thealpaca, theguanaco, and thevicuña.[2]
The earliest known camel, calledProtylopus, lived in North America 40 to 50 million years ago, during theEocene.[3] It was about the size of a rabbit and lived in the open woodlands of what is nowSouth Dakota.[4]
Camels live in deserts, where it is hot and dry. Camels have adapted and found ways to help them survive in deserts. They have a thick coat of hair that protects them from the heat in the day, and keeps them warm at night. Their large feet spreads their weight on the sand when they are walking. When there is food and water, a camel can eat and drink large amounts of it and store it asfat in the hump. Then, when there is no food or water, the camel uses the fat for energy, and the hump becomes small and soft. A camel’s waste contains very little water. Even the water from the camel’s breath flows back into its mouth. The camels have bushy eyebrows that don't let the sand go in their eyes in a sandstorm. It has a long slender neck in order to reach high leaves such as palm trees, and rubbery patches on the belly and knees to protect the skin when kneeling and sitting on the hot sand. These form after five years of age.
A camel has a naturally adaptedtemperature regulation - it can change its bodily temperature by six degrees Celsius either way. It has two sets of eyelashes, closing muscles in the nasal passages, hairy ears and tough, leathery skin to protect the camels skin in sandstorms. It has thick rubbery lips to eat dry, prickly plants and a large, haired tail to swat pests such as mosquitos and flies.
An unborn camelgestates about 9 to 11 months. There is usually one calf per birth. A camel calf can run only a few hours after it is born. Calves areweaned to when they are about 1 year old.
In the desert, people feed camels withgrass,grains,wheat andoats. When camels are travelling in the desert, food is often very hard to find. So the animal might have to live on dried leaves,seeds, andthornytwigs (without hurting their mouths). If there is not any regular food, camels will eat anything.
Camels areruminants, which have a two-part cycle in their eating. The first stomachferments the food for a time. Then, this food (orcud) returns to the camel's mouth, and the camel chews it again. Then the camel swallows the cud and it goes to the other parts of the stomach to be completelydigested. The digestion is done mainly by microorganisms in the stomachs.
This adaptation means they can eat food which may not be very nutritious, but they get everything possible out of it. Ruminants are a very successful group of mammals, and this double-stomach arrangement is one of their key adaptations. Most of them eat fairly tough plant material.
Camels have beendomesticated by humans for about 5000 years. They are used forriding and to carry things, and formeat,milk andwool.
As domesticated animals, they are used in Africa, Asia, and since the19th century also inAustralia. About 900-1000 wild Bactrian Camels still live inChina, Tibetan Plateau andMongolia. There are no wild dromedaries anymore, but there are escaped domestic dromedaries in Australia. Today there are dromedaries living wild in theoutback in Australia.[5]
↑Harington, C. R. (June 1997)."Ice Age Yukon and Alaskan Camels".Yukon Beringia Interpretive Centre. Government of Yukon, Department of Tourism and Culture, Museums Unit. Archived fromthe original on 26 January 2013. Retrieved3 December 2012.
↑Saalfeld W.K. & Edwards GP 2008. Ecology of feral camels in Australia (DKCRC Report 47).Managing the impacts of feral camels in Australia: a new way of doing business. Alice Springs: Desert Knowledge Cooperative Research Centre.ISBN 978-1-74158-094-5. ISSN 1832-6684. Archived (PDF) from the original on 2012-03-29.
