Mule

A female mule that has oestrus cycles, and which could thus in theory carry a foetus, is called a "molly" or "Molly mule", though the term is sometimes used to refer to female mules in general. A male mule is properly called a "horse mule", though often called a "john mule", which is the correct term for a gelded mule. A young male mule is called a "mule colt", and a young female is called a "mule filly".[4]

Painting in the Tomb of Nebamun at Thebes, showing a pair of animals which could be mules or onagers

Ancient Greek rhyton in the shape of the head of a mule, made by Brygos, early fifth century BC, Jérôme Carcopino Museum, Aleria, Corsica

Breeding of mules became possible only when the range of the domestic horse, which originated in Central Asia in about 3500 BC, extended into that of the domestic ass, which originated in north-eastern Africa. This overlap probably occurred in Anatolia and Mesopotamia in Western Asia, and mules were bred there before 1000 BC.[5]^: 37

A painting in the Tomb of Nebamun at Thebes, dating from approximately 1350 BC, shows a chariot drawn by a pair of animals which have been variously identified as onagers,[6] as mules[5]^: 37 or as hinnies.[7]^: 96 Mules were present in Israel and Judah in the time of King David.[5]^: 37 There are many representations of them in Mesopotamian works of art dating from the first millennium BC. Among the bas-reliefs depicting the Lion Hunt of Ashurbanipal from the North Palace of Nineveh is a clear and detailed image of two mules loaded with nets for hunting.[7]^: 96[8]

Homer noted their arrival in Asia Minor in the Iliad in 800 BC.[9]

Christopher Columbus brought mules to the New World.[10]

Mule and Ass by Hendrik Goltzius or Hieronymus Wierix, 1578

George Washington bred mules at his home at Mount Vernon. At the time, they were not common in the United States, but Washington understood their value, as they were "more docile than donkeys and cheap to maintain."[11] In the nineteenth century, they were used in various capacities as draught animals - on farms, especially where clay made the soil slippery and sticky; pulling canal boats; and famously for pulling, often in teams of 20 or more animals, wagonloads of borax out of Death Valley, California from 1883 to 1889. The wagons were among the largest ever pulled by draught animals, designed to carry 10 short tons (9 metric tons) of borax ore at a time.[12]

Mules were used by armies to transport supplies, occasionally as mobile firing platforms for smaller cannons, and to pull heavier field guns with wheels over mountainous trails such as in Afghanistan during the Second Anglo-Afghan War.[13]

In the second half of the twentieth century, widespread use of mules declined in industrialised countries. The use of mules for farming and for transportation of agricultural products largely gave way to steam-, then diesel-powered, tractors and lorries.

On 5 May 2003 Idaho Gem, a mule foal cloned by nuclear transfer of cells from foetal material, was born at the University of Idaho in Moscow, Idaho.[14]^: 2924[15] Neither an equid nor a hybrid animal had been cloned before.[14]^: 2924[15]

Loading mules, from Eleven Years in the Rocky Mountains and a Life on the Frontier by Frances Fuller Victor, 1887

In general terms, in both the mule and the hinny the foreparts and head of the animal are similar to those of the sire, while the hindparts and tail tend to resemble those of the dam.[5]^: 36 A mule is generally larger than a hinny, with longer ears and a heavier head; the tail is usually covered with long hair like that of its mare mother.[5]^: 37 A mule has the thin limbs, small narrow hooves and short mane of the donkey, while its height, the shape of the neck and body, the uniformity of its coat and its teeth are more similar to those of the horse.[16]

Mules vary widely in size, from small miniature mules under 125 cm (50 in) to large and powerful draught mules standing up to 180 cm (70 in) at the withers.[17]^: 86 The median weight range is between about 370 and 460 kg (820 and 1000 lb).[18]

The coat may be of any colour seen in the horse or in the donkey. Mules usually display the light points commonly seen in donkeys: pale or mealy areas on the belly and the insides of the thighs, on the muzzle, and round the eyes. They often have primitive markings such as dorsal stripe, shoulder stripe or zebra stripes on the legs.[5]^: 37

The mule exhibits hybrid vigour.[19] Charles Darwin wrote: "The mule always appears to me a most surprising animal. That a hybrid should possess more reason, memory, obstinacy, social affection, powers of muscular endurance, and length of life, than either of its parents, seems to indicate that art has here outdone nature".[20]

The mule inherits from its sire the traits of intelligence, sure-footedness, toughness, endurance, disposition, and natural cautiousness. From its dam it inherits speed, conformation, and agility.[21]^{: 5–6, 8} Mules are reputed to exhibit a higher cognitive intelligence than their parent species, but robust scientific evidence to back up these claims is lacking. Preliminary data exist from at least two evidence-based studies, but they rely on a limited set of specialised cognitive tests and a small number of subjects.[22][23] Mules are generally taller at the shoulder than donkeys and have better endurance than horses, although a lower top speed.[22]

In the early twentieth century the mule was preferred to the horse as a pack animal – its skin is harder and less sensitive than that of a horse, and it is better able to bear heavy weights.[16]

A 20-mule team in Death Valley, California

While a few mules can carry live weight up to 160 kg (353 lb), the superiority of the mule becomes apparent in their additional endurance.[30] In general, a mule can be packed with dead weight up to 20% of its body weight, or around 90 kg (198 lb).[30] Although it depends on the individual animal, mules trained by the Army of Pakistan are reported to be able to carry up to 72 kg (159 lb) and walk 26 km (16.2 mi) without resting.[31] The average equine in general can carry up to roughly 30% of its body weight in live weight, such as a rider.[32]

About 3.5 million donkeys and mules are slaughtered each year for meat worldwide.[33]

Mule trains have been part of working portions of transportation links as recently as 2005 by the World Food Programme,[34] and are still used extensively to transport cargo in rugged, roadless regions.

The Food and Agriculture Organization of the United Nations reports that China was the top market for mules in 2003, closely followed by Mexico and many Central and South American nations.

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  The Devil's Bridge at Schöllenen Gorge, drawing by Peter Birmann
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  Mule train fording the Quesnel River, 1868
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  Mule battery in the Second Anglo-Afghan War, 1879–1880
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  British mule train during the Second Anglo-Boer War in South Africa
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  Mule train in British Columbia, 1911
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  Mule cars in Celaya, Guanajuato, Mexico, 1930s
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  Unloading US Army mules in Naples, Italy, in September, 1944
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  Ploughing with a mule, Saluda, South Carolina, 1947
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  Mules delivering mail, Supai, Arizona, 2008
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  On the South Kaibab trail in the Grand Canyon

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