An Indian camel herder leads his herd at the annual camel & livestock fair in Pushkar, India., on Nov. 20.

Indian camel herders walk with their herd as they arrive to sell their camels at the fair on Nov. 21.

Indian camel herders sit next to their herd on Nov. 20.

Two boys walk past camels at the fair on Nov. 21.

An Indian camel herder pulls a reluctant camel at the fair on Nov. 20.

A group of camel traders sit around a fire in the early morning hours at the camel fair grounds on the outskirts of Pushkar on Nov. 21, 2012.

An Indian man rides a camel as he pursues another during a camel race at the fair on Nov. 21.

A camel that was purchased by a customer is lifted to be placed in a vehicle at a camel market near Riyadh, Saudi Arabia, on October 23, 2012. Muslims around the world are preparing to celebrate Eid al-Adha (the feast of sacrifice), marking the end of the Hajj, by slaughtering sheep, goats, cows and camels to commemorate Prophet Abraham's willingness to sacrifice his son Ismail on God's command.

Helpers prepare just-purchased camels for their new owners to take with them at the livestock market in the desert village of Sakabal, Niger. Eighty percent of Niger's people and 100 percent of the landlocked nation's rural population depend on livestock, including camel, cows, sheep and goats, for some part of their income. For generations, nomads have lived in a precarious equilibrium with the sky above them. When the first rains come, they head north toward the Sahara desert, where the grass is said to be saltier, packed with minerals. They time their movements according to the clouds, waiting for the second major downpour, before making a U-turn to head back to the greener south. If they miscalculate, they can end up stranded. As the grass turns yellow, their animals become too weak to walk.

Herdsmen gather at the livestock market.

Tuareg nomads arrive at the market to trade livestock in Bermo, Niger.

A Tuareg nomad carrying his traditional sword has a hook fit to his camel at the market in Bermo, Niger.

A Peul merchant relaxes on his stick by the door of a house while attending the livestock market in Bermo, Niger.

Men walk through the grain market in the desert village of Sakabal, Niger.

Tuareg nomads carrying their traditional swords and good luck amulets around their neck, shop for fabric and other goods while attending the livestock market in Bermo, Niger.

A Nigerian taxman records the sale of a camel at the market in Bermo, Niger.

A rare vehicle carries villagers back to Bermo, Niger.

A Tuareg nomad, carrying his traditional sword, walks past a handler pulling just-purchased sheep to their new owner at the livestock market in Bermo, Niger.

Sold goats are loaded on the rooftop of a truck in the desert village of Sakabal, Niger.

A herdsman's family heats up water for dinner in the fields near Bermo, Niger.

A young herdsman walks through his cattle outside Bermo, Niger.

Birds fly over grazing cows in the green sandy plains near Bermo, Niger.

Young herdsmen show their henna stained hands, sign of a recent wedding celebration, as they gather at the livestock market in the desert village of Sakabal, Niger.

A Tuareg nomad, carrying his traditional sword, rides his camel as he leaves the livestock market in Bermo, Niger.

Livestock merchants leave Bermo, Niger.

In this picture taken Monday, July 16, 2012, nomads stop for the night between Dakoro and Bermo, Niger.

A zoo official prepares to tie the mouth of an African lion, after it was successfully anesthetized at Taman Satwa Jurug in Solo, in Indonesia's Java province, on Jan. 31, 2012.

Paramilitary soldiers of the Indian Border Security Force wait with their musical instruments and camels amidst winter morning fog before the start of Republic Day parade rehearsals in New Delhi, India, on Jan. 18, 2012.

Indian army soldiers sit amidst winter morning fog for Republic Day parade rehearsals in New Delhi on Jan. 18, 2012.

A villager looks at a camel before deciding to buy at the Pushkar fair, in the Indian state of Rajasthan, on Nov. 5. Pushkar, located on the banks of Pushkar Lake, is a popular Hindu pilgrimage spot that is also frequented by foreign tourists for its annual cattle fair and camel races. The week-long fair began Thursday.

A herder looks at three camels he purchased during the camel fair in Pushkar on Nov. 4. The Pushkar fair is one of the world's largest camel fairs, with over 50,000 camels brought in from around the region.

A herder rests at the end of the day in Pushkar on Nov. 4.

Camels stand on the motorway between Misrata and Sirte, on August 30. Libyan rebles were advancing towards Syrte, fallen leader Moamar Gadhafi's hometown and the last bastion of loyalists.