Equus asinusass(Also: donkey)

Geographic Range

True wild asses are found only in northern Africa and the Arabian peninsula, but domesticated and feral donkeys can now be found in all parts of the world. The native range extends from Morocco to Somalia and Mesopotamia to Oman. (Nowak, 1997; The American Donkey and Mule Society, 1998)

Habitat

Domestic donkeys are widely distributed and can be found almost everywhere in the world. However, true wild asses originated in the hilly, undulating deserts of northern Africa and the Arabian peninsula and are well-adapted for life in the desert. Domestic donkeys prefer warm, dry climates and, if left to become feral, they will return to such a habitat, like the feral burros of Death Valley National Park in California. Deserts are characterized by low, unpredictable rainfall and sparse vegetation. (Dossenbach, 1983; Nowak, 1997; Phillips and The Wild Burro Rescue and Preservation Project, 1999; The American Donkey and Mule Society, 1998)

Physical Description

Donkeys resemble horses and are characterized by their large head, long ears, and cow-like tail. They come in black, white, paint, and all shades of brown and gray, but the most common is a mousy gray color called gray dun. Many donkeys are spotted, speckled, or striped. Most solid-color donkeys have a dark dorsal stripe from mane to tail and a dark stripe across their shoulders. They have an erect mane and lack the forelock of a horse. Their hair can be straight, curly, short and wiry, or long and wooly. Wild asses average 200 cm in body length, 45 cm in tail length, 125 cm at the shoulder, and weight 250 kg. Domestic breed size varies greatly depending on breed. Miniatures, the smallest breed of donkeys, stand less than 36 inches (92 cm) at the shoulder and weigh less than 400 pounds (180 kg). Standard donkeys, the average-sized breed, range from 36 inches to 48 inches (92 cm to 123 cm) and weigh 400 to 500 pounds (180 to 225 kg). Mammoth stock, the largest breed of donkeys, stand at an average height of 56 inches (143 cm) and weigh about 950 pounds (430 kg). Miniature and mammoth stock donkeys have been bred by humans to possess certain characteristics that are more desirable or suitable for specific purposes. For example, miniature donkeys are often preferred as pets because their small size makes them easier to care for, and the larger mammoth stock donkeys are stronger work animals than standard donkeys are. There is generally very little sexual dimorphism in donkeys. Wild asses have the longest and narrowest hooves of any Equus species. (Edwards and Geddes, 1988; Nowak, 1997; Oklahoma State University, 1996a; Oklahoma State University, 1996b; The American Donkey and Mule Society, 1998; The Encyclopaedia Brittanica, 15th ed., Vol. 4, 1992)

  • Sexual Dimorphism
  • sexes alike
  • Average mass
    250 kg
    550.66 lb
  • Average mass
    250000 g
    8810.57 oz
    AnAge
  • Average length
    200 cm
    78.74 in
  • Average basal metabolic rate
    164.92 W
    AnAge

Reproduction

Smaller herds of wild asses are generally made up of one male and several females. Larger herds have multiple males and females. There don't seem to be any permanent bonds among individuals, herds are highly flexible, breaking up and reforming on an almost daily basis. Dominant male wild asses sometimes defend large territories in which many potential mates are also found. Subordinate males are also tolerated within the dominant male's territory. (Nowak, 1997)

Domesticated donkeys can be bred at any time of year, wild asses generally breed in the wet season. The gestation period is usually 12 months, and foals weigh between 19 and 30 pounds (8.6 to 13.6 kg) at birth. Donkey foals are fully developed at birth and can usually stand and nurse about 30 minutes after birth. The young are weaned from the mother at about 5 months of age. Females reach sexual maturity at 2 years of age and can give birth to one foal each year after that. Males may reach sexual maturity as early as 2 years old but are more likely to become dominant enough to control mating at 3 to 4 years old.

Members of the genus Equus can often interbreed to produce hybrids. Donkeys can be bred with horses and zebras to produce sterile hybrids. A cross between a male donkey (jack) and a female horse (mare) produces a mule. A cross between a female donkey (jennet or jenny) and a male horse (stallion) produces a hinny. A cross between a zebra and a donkey produces a zebrass or a zonkey. (Edwards and Geddes, 1988; Honolulu Zoo, 2000; Jacks or Better Donkey Co., 2000a; Jacks or Better Donkey Co., 2000b; Nowak, 1997; Rachau, 1996)

  • Breeding interval
    Wild asses give birth each year.
  • Breeding season
    Breeding generally occurs in the wet season in the wild, although domestic and some feral populations breed year-round.
  • Average number of offspring
    1
  • Average number of offspring
    1
    AnAge
  • Average gestation period
    12 months
  • Average gestation period
    359 days
    AnAge
  • Average weaning age
    5 months
  • Average age at sexual or reproductive maturity (female)
    2 years
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    708 days
    AnAge
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    1005 days
    AnAge

Female wild asses nurse and care for their young until they are weaned at about 5 months old. Young wild asses are capable of standing and following their mothers within a few hours of birth. (Nowak, 1997)

  • Parental Investment
  • no parental involvement
  • precocial
  • pre-fertilization
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female
  • pre-independence
    • provisioning
      • female
    • protecting
      • female

Lifespan/Longevity

The average life span of a wild donkey is 25 to 30 years, but in captivity they can live to be 40 to 50 years old. (Nowak, 1997)

  • Average lifespan
    Status: wild
    25-30 years
  • Range lifespan
    Status: captivity
    40-50 (high) years
  • Typical lifespan
    Status: wild
    25 to 30 years
  • Average lifespan
    Status: captivity
    47.0 years
    Max Planck Institute for Demographic Research

Behavior

Donkeys are social animals. They are most active in the morning and evening, resting during the heat of the day. In the wild they travel in herds of several individuals to up to one hundred individuals, with an average group size of 4.7 animals.

Donkeys are observant and cautious animals. They will refuse to do anything that seems dangerous to them. This behavior has earned the donkey its reputation for being stubborn, but actually, domestic donkeys are very obedient animals and will not refuse any reasonable order. When a donkey is startled by something, it usually will not run blindly in fear. Its natural instinct is to freeze or run a few steps, then look to see what frightened it. This is unlike the behavior of horses, which tend to panic and "bolt" when frightened.

Domestic donkeys interact well with other livestock animals such as horses, cows, goats, sheep, and llamas. Donkeys are passive by nature, but will aggressively protect their young, and can be trained to protect sheep and goats as well. Donkeys will not hesitate to attack and trample large dogs or even humans if they perceive the animal to be a threat.

Standard size domestic donkeys are useful for halter-breaking young calves and foals. By giving the donkey the job of training the animals, the calf or foal will be more inclined to trust a human, since they do not associate the unpleasant training experience with the human.

Donkeys are used as companions for weaned foals and for nervous, injured, or recovering animals. They have a calming, soothing effect on the animals and help to reduce the stress of traumatic situations.

Donkeys are also being used as companion animals in recreational riding programs for children and for mentally and physically handicapped people. Their affectionate, calm, patient disposition make them ideal for use as a companion animal for other livestock and people. (Honolulu Zoo, 2000; Nowak, 1997; Oklahoma State University, 1996a; Oklahoma State University, 1996b; Rachau, 1996)

  • Range territory size
    23 (high) km^2

Home Range

Mean annual home ranges have been estimated at 19.2 square kilometers. (Nowak, 1997)

Communication and Perception

Wild asses use visual displays, smells, physical contact, and vocalizations to communicate. They have keen hearing and good senses of vision and smell.

Food Habits

Donkeys are grazing herbivores, with large, flat-surfaced teeth adapted for tearing and chewing plant matter. Their primary food is grass, but they also eat other shrubs and desert plants. Like many other grazing animals, they grasp the plant first with their muscular lips, pull it into their mouth, and then tear it off with their teeth.

In a study of feral donkeys in Arizona, they were found to eat 33% forbs and 40% browse. (Nowak, 1997)

  • Plant Foods
  • leaves
  • wood, bark, or stems

Predation

Living in groups increases the number of animals keeping an eye out for predators. Most predation probably occurs on foals and elderly animals. Predators on wild donkeys may have included lions and wolves.

Ecosystem Roles

Wild donkeys impact desert vegetation through their grazing and browsing.

Economic Importance for Humans: Positive

Since donkeys were first domesticated about six thousand years ago, they have been very important in human economies. Egyptian tombs of Dynasty IV (ca. 2675 to 2565 B.C.) indicate that ownership of donkeys was a status symbol, and the elite of society may have owned herds of over a thousand head. Donkeys played a very important role in developing long-distance trade in Egypt, because of their weight-bearing capacity and their adaptation for desert travel. In ancient Egypt, female donkeys were kept as dairy animals. Donkey milk is higher in sugar and protein than cow's milk. The milk was also used for cosmetic and medicinal purposes. Donkey meat was eaten as food by many people. There were domesticated donkeys in Europe by the second millenium B.C. and the first donkeys came to the New World with Christopher Columbus in 1495. Donkeys were introduced to the United States with Mexican explorers. Many of the wild donkeys in the southwestern United States are descendants of escaped or abandoned burros brought by Mexican explorers during the Gold Rush. Throughout history donkeys have been invaluable as beasts of burden. Even today, donkeys are of great economic importance especially in remote areas. They are being used extensively in efforts to boost the economy and alleviate poverty in poorer areas of the world. Miniature donkeys are very popular as companion animals and for show. Mammoth stock are still used as draft animals in small farming businesses around the world. (Dossenbach, 1983; Edwards and Geddes, 1988; The American Donkey and Mule Society, 1998)

  • Positive Impacts
  • food
  • body parts are source of valuable material

Economic Importance for Humans: Negative

The cost of population control of feral donkeys in North America and Europe have been appreciable in some areas. Feral donkeys may contribute to habitat degradation and erosion, particularly in areas where they are not native. (Phillips and The Wild Burro Rescue and Preservation Project, 1999)

Conservation Status

Although the future of wild and feral donkeys is uncertain, domestic donkeys are not in danger of extinction in the foreseeable future. However, donkey lovers in the United States and Europe have founded many organizations dedicated to the rescue, preservation, and care of wild, abandoned, or unwanted donkeys. Feral donkeys in Death Valley National Park, California, were under strict population control for many years because they were competing with desert bighorn sheep for very limited resources. Many authorities felt that donkeys were driving the already threatened bighorn sheep to extinction, and about 400 wild donkeys were shot between 1987 and 1995 by National Park Service Rangers as part of their "Direct Reduction" policy. (Dossenbach, 1983; Phillips and The Wild Burro Rescue and Preservation Project, 1999)

Other Comments

Donkeys have a long and interesting history and their close interaction with humans has resulted in a rich legacy of folklore and myth in ancient Middle-Eastern cultures, and donkeys are included in many biblical stories. (Nowak, 1997)

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Britton Huggins (author), Fresno City College, Jerry Kirkhart (editor), Fresno City College.

Glossary

Australian

Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

World Map

Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

World Map

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

Palearctic

living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

World Map

acoustic

uses sound to communicate

agricultural

living in landscapes dominated by human agriculture.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

cosmopolitan

having a worldwide distribution. Found on all continents (except maybe Antarctica) and in all biogeographic provinces; or in all the major oceans (Atlantic, Indian, and Pacific.

desert or dunes

in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.

diurnal
  1. active during the day, 2. lasting for one day.
endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

folivore

an animal that mainly eats leaves.

food

A substance that provides both nutrients and energy to a living thing.

herbivore

An animal that eats mainly plants or parts of plants.

introduced

referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nomadic

generally wanders from place to place, usually within a well-defined range.

oceanic islands

islands that are not part of continental shelf areas, they are not, and have never been, connected to a continental land mass, most typically these are volcanic islands.

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

World Map

polygynous

having more than one female as a mate at one time

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5? N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

year-round breeding

breeding takes place throughout the year

young precocial

young are relatively well-developed when born

References

Animal Traction Network for Eastern and Southern Africa, "Donkey Workshop" (On-line). Accessed October 4, 2000 at http://www.atnesa.org/donkeyworkshop.htm.

Dossenbach, M. 1983. The Noble Horse. Boston: G. K. Hall.

Edwards, E., C. Geddes. 1988. The Complete Horse Book. North Pomfret, Vermont: Trafalgar Square Publishing.

EnchantedLearning.com, 2000. "Donkey" (On-line). Accessed October 3, 2000 at http://www.zoomwhales.com/subjects/mammals/horse/Donkeyprintout/shtml.

Honolulu Zoo, 2000. "Donkey" (On-line). Accessed October 3, 2000 at http://www.honoluluzoo.org/donkey.htm.

Jacks or Better Donkey Co., 2000. "ASStute Facts" (On-line). Accessed October 3, 2000 at http://jacksorbetterdonkey.com/ASStute%20Facts.htm.

Jacks or Better Donkey Co., 2000. "Home Page" (On-line). Accessed October 3, 2000 at http://jacksorbetterdonkey.com/.

Nowak, R. 1997. Walker's Mammals of the World. Baltimore: The Johns Hopkins University Press. Accessed May 15, 2004 at http://www.press.jhu.edu/books/walkers_mammals_of_the_world/perissodactyla/perissodactyla.equidae.equus.html.

Oklahoma State University, 1996. "Donkey Breeds" (On-line). Accessed September 29, 2000 at http://www.ansi.okstate.edu/breeds/other/donkey/.

Oklahoma State University, 1996. "Miniature" (On-line). Accessed October 2, 2000 at http://www.ansi.okstate.edu/breeds/other/donkey/mini/.

Phillips, E., The Wild Burro Rescue and Preservation Project. 1999. "Home Page" (On-line). Accessed October 3, 2000 at http://home.earthlink.net/~emilylee.

Rachau, J. 1996. "The Donkey: Somewhat Defined" (On-line). Accessed October 3, 2000 at http://www.orednet.org/~jrachau/defined.htm.

The American Donkey and Mule Society, 1998. "Donkey" (On-line). Accessed October 2, 2000 at http://www.imh.org/imh/bw/donkey.html.

The Encyclopaedia Brittanica, 15th ed., Vol. 4, 1992. Chicago: University of Chicago.