Donkey

Appearance

Donkeys vary considerably in size, depending on both breed and environmental conditions, and heights at the withers range from less than 90 centimetres to approximately 150 cm . Working donkeys in the poorest countries have a life expectancy of 12 to 15 years; in more prosperous countries, they may have a lifespan of 30 to 50 years.

Donkeys are adapted to marginal desert lands. Unlike wild and feral horses, wild donkeys in dry areas are solitary and do not form harems. Each adult donkey establishes a home range; breeding over a large area may be dominated by one jack. The loud call or bray of the donkey, which typically lasts for twenty seconds and can be heard for over three kilometres, may help keep in contact with other donkeys over the wide spaces of the desert. Donkeys have large ears, which may pick up more distant sounds, and may help cool the donkey's blood. Donkeys can defend themselves by biting, striking with the front hooves or kicking with the hind legs. Their vocalization, called a bray, is often represented in English as "hee haw".

Distribution

In some areas domestic donkeys have returned to the wild and established feral populations such as those of the burro of North America and the Asinara donkey of Sardinia, Italy, both of which have protected status. Feral donkeys can also cause problems, notably in environments that have evolved free of any form of equid, such as Hawaii. In Australia, where there may be 5 million feral donkeys, they are regarded as an invasive pest and have a serious impact on the environment. They may compete with livestock and native animals for resources, spread weeds and diseases, foul or damage watering holes and cause erosion.

Status

About 41 million donkeys were reported worldwide in 2006. China had the most with 11 million, followed by Pakistan, Ethiopia and Mexico. As of 2017, however, the Chinese population was reported to have dropped to 3 million, with African populations under pressure as well, due to increasing trade and demand for donkey products in China. Some researchers believe the actual number may be somewhat higher since many donkeys go uncounted. The number of breeds and percentage of world population for each of the FAO's world regions was in 2006:





In 1997 the number of donkeys in the world was reported to be continuing to grow, as it had steadily done throughout most of history; factors cited as contributing to this were increasing human population, progress in economic development and social stability in some poorer nations, conversion of forests to farm and range land, rising prices of motor vehicles and fuel, and the popularity of donkeys as pets.
Since then, the world population of donkeys is reported to be rapidly shrinking, falling from 43.7 million to 43.5 million between 1995 and 2000, and to only 41 million in 2006. The fall in population is pronounced in developed countries; in Europe, the total number of donkeys fell from 3 million in 1944 to just over 1 million in 1994.

The Domestic Animal Diversity Information System of the FAO listed 189 breeds of ass in June 2011. In 2000 the number of breeds of donkey recorded worldwide was 97, and in 1995 it was 77. The rapid increase is attributed to attention paid to identification and recognition of donkey breeds by the FAO's Animal Genetic Resources project. The rate of recognition of new breeds has been particularly high in some developed countries. In France only one breed, the Baudet du Poitou, was recognised until the early 1990s; by 2005, a further six donkey breeds had official recognition.

In developed countries, the welfare of donkeys both at home and abroad has become a concern, and a number of sanctuaries for retired and rescued donkeys have been set up. The largest is The Donkey Sanctuary near Sidmouth, England, which also supports donkey welfare projects in Egypt, Ethiopia, India, Kenya, and Mexico.

In 2017, a drop in the number of Chinese donkeys, combined with the fact that they are slow to reproduce, meant that Chinese suppliers began to look to Africa. As a result of the increase in demand, and the price that could be charged, Kenya opened three donkey abattoirs. Concerns for donkeys' well-being, however, have resulted in a number of African countries banning China from buying their donkey products.

In 2019, The Donkey Sanctuary warned that the global donkey population could be reduced by half over the next half decade as the demand for ejiao increases in China.

Behavior

Donkeys have a notorious reputation for stubbornness, but this has been attributed to a much stronger sense of self-preservation than exhibited by horses. Likely based on a stronger prey instinct and a weaker connection with humans, it is considerably more difficult to force or frighten a donkey into doing something it perceives to be dangerous for whatever reason. Once a person has earned their confidence they can be willing and companionable partners and very dependable in work.

Although formal studies of their behaviour and cognition are rather limited, donkeys appear to be quite intelligent, cautious, friendly, playful, and eager to learn.

Reproduction

A jenny is normally pregnant for about 12 months, though the gestation period varies from 11 to 14 months, and usually gives birth to a single foal. Births of twins are rare, though less so than in horses. About 1.7 percent of donkey pregnancies result in twins; both foals survive in about 14 percent of those. In general jennies have a conception rate that is lower than that of horses .

Although jennies come into heat within 9 or 10 days of giving birth, their fertility remains low, and it is likely the reproductive tract has not returned to normal. Thus it is usual to wait one or two further oestrous cycles before rebreeding, unlike the practice with mares. Jennies are usually very protective of their foals, and some will not come into estrus while they have a foal at side. The time lapse involved in rebreeding, and the length of a jenny's gestation, means that a jenny will have fewer than one foal per year. Because of this and the longer gestation period, donkey breeders do not expect to obtain a foal every year, as horse breeders often do, but may plan for three foals in four years.

Donkeys can interbreed with other members of the family Equidae, and are commonly interbred with horses. The hybrid between a jack and a mare is a mule, valued as a working and riding animal in many countries. Some large donkey breeds such as the Asino di Martina Franca, the Baudet du Poitou and the Mammoth Jack are raised only for mule production. The hybrid between a stallion and a jenny is a hinny, and is less common. Like other inter-species hybrids, mules and hinnies are usually sterile. Donkeys can also breed with zebras, in which case the offspring is called a zonkey .

Evolution

The genus ''Equus'', which includes all extant equines, is believed to have evolved from ''Dinohippus'', via the intermediate form ''Plesippus''. One of the oldest species is ''Equus simplicidens'', described as zebra-like with a donkey-shaped head. The oldest fossil to date is ~3.5 million years old from Idaho, USA. The genus appears to have spread quickly into the Old World, with the similarly aged ''Equus livenzovensis'' documented from western Europe and Russia.

Molecular phylogenies indicate the most recent common ancestor of all modern equids lived ~5.6 mya. Direct paleogenomic sequencing of a 700,000-year-old middle Pleistocene horse metapodial bone from Canada implies a more recent 4.07 Myr before present date for the most recent common ancestor within the range of 4.0 to 4.5 Myr BP. The oldest divergencies are the Asian hemiones '', including the kulan, onager, and kiang), followed by the African zebras '', and ''E. ''). All other modern forms including the domesticated horse belong to the subgenus ''E. '' which diverged ~4.8 million years ago.

The ancestors of the modern donkey are the Nubian and Somalian subspecies of African wild ass. Remains of domestic donkeys dating to the fourth millennium BC have been found in Ma'adi in Lower Egypt, and it is believed that the domestication of the donkey was accomplished long after the domestication of cattle, sheep and goats in the seventh and eighth millennia BC. Donkeys were probably first domesticated by pastoral people in Nubia, and they supplanted the ox as the chief pack animal of that culture. The domestication of donkeys served to increase the mobility of pastoral cultures, having the advantage over ruminants of not needing time to chew their cud, and were vital in the development of long-distance trade across Egypt. In the Dynasty IV era of Egypt, between 2675 and 2565 BC, wealthy members of society were known to own over 1,000 donkeys, employed in agriculture, as dairy and meat animals and as pack animals. In 2003, the tomb of either King Narmer or King Hor-Aha was excavated and the skeletons of ten donkeys were found buried in a manner usually used with high ranking humans. These burials show the importance of donkeys to the early Egyptian state and its ruler.

By the end of the fourth millennium BC, the donkey had spread to Southwest Asia, and the main breeding centre had shifted to Mesopotamia by 1800 BC. The breeding of large, white riding asses made Damascus famous, while Syrian breeders developed at least three other breeds, including one preferred by women for its easy gait. The Muscat or Yemen ass was developed in Arabia. By the second millennium BC, the donkey was brought to Europe, possibly at the same time as viticulture was introduced, as the donkey is associated with the Syrian god of wine, Dionysus. Greeks spread both of these to many of their colonies, including those in what are now Italy, France and Spain; Romans dispersed them throughout their empire.

The first donkeys came to the Americas on ships of the Second Voyage of Christopher Columbus, and were landed at Hispaniola in 1495. The first to reach North America may have been two animals taken to Mexico by Juan de Zumárraga, the first bishop of Mexico, who arrived there on 6 December 1528, while the first donkeys to reach what is now the United States may have crossed the Rio Grande with Juan de Oñate in April 1598. From that time on they spread northward, finding use in missions and mines. Donkeys were documented as present in what today is Arizona in 1679. By the Gold Rush years of the 19th century, the burro was the beast of burden of choice of early prospectors in the western United States. With the end of the placer mining boom, many of them escaped or were abandoned, and a feral population established itself.