But some enterprising transportation professionals use donkeys to ferry their passengers and merchandise across Khartoum.

For nearly 20 years, Musa Shuker has set out from his home in the Soba Aradi shantytown 18 kilometres south of Khartoum at daybreak astride a donkey to make a modest living in the streets of the capital.

He distributes a dozen 20-litre jerrycans of water to a variety of clients ranging from sidewalk tea vendors to thirsty construction site workers.

Mr. Shuker's daily take-home usually comes to around 44 Sudanese pounds ($20), and his donkey cart is sometimes hired for the transport of mud, bricks and other construction materials at a rate of between five and ten pounds for each job.

"Without the donkey, I would have raised children who are malnourished because of starvation and poor medical attention," the father of ten said. "But because of it, my children have never suffered an acute lack of food or insufficient medical care."

Thanks to his donkey business, Mr. Shuker was able to put his elder daughter through university and send his son to secondary school and electrical engineering training courses that recently landed him gainful employment.

The income of donkey owners varies widely. When he is making the rounds on his animal, Ahmed Yagug earns 20 pounds ($9) a day – or roughly half of Mr. Shuker's average receipts – but that sum drops to only 7 pounds when he rents out the donkey as he is doing at present.

However, his profit margins swell during occasional power cuts in town as demand for water among households and businesses suddenly spikes.

A creative use of the beast of burden is "donkey for hire," which can be a popular diversion at social events such as a wedding. Donkeys are cheaper than buses and can carry an entire stereo music system on their backs, according to Charles Lubajo, a Khartoum resident for more than 20 years who recently returned to his native Southern Sudan last April.

Donkeys are also used for shuttling children between their homes and schools, bringing crops and vegetables to the city's open-air markets and delivering trash to garbage dumps.

"The maximum cost for taking children over a distance of ten kilometres is five pounds, as opposed to 20 pounds on a rickshaw and 30 pounds on a taxi," noted Mr. Lubajo, adding that he once was taken to a health clinic via donkey cart when his family could not locate a taxi.

Donkeys are especially useful for reaching destinations that are inaccessible to buses, taxis and rickshaws. They are also a nimble, all-weather means of conveyance capable of negotiating potholed streets and flooded alleys after a heavy downpour.

But the four-legged beasts are not made of steel and must contend with disease and harsh climate conditions throughout the year. "It is too hot here in Khartoum," notes 35-year-old Mohammed Babiker of the Mayo internally displaced persons' camp located south-west of the capital.

"My donkey falls sick very often," he added. "My business comes to an abrupt standstill for a week or so if my animal falls sick, which badly affects my earnings that month."

To ensure a steady income, Mr. Shuker tries to treat his donkey right. He refrains from caning the animal and feeds it sorghum and grass to maintain its strength for bearing heavy loads.

"If you are stubborn, the animal will also be acting up," said the 56-year-old donkey owner. "But if you look up to it, it will also give back the same respect to you."