Equus asinusass(Also: donkey)

Geographic Range

African wild asses (Equus asinus africanus) are found throughout the northeastern part of Africa. They can be found in the northern parts of Sudan, Ethiopia, and Djibouti. Their total range has been recorded by Moehlman et al. (2015) to be around 23,000 km2. Asses have also been domesticated worldwide, where they are commonly referred to as donkeys (Equus asinus asinus). (Bauer, et al., 1994; Moehlman, et al., 2015)

Habitat

African wild asses live in desert environments with less rainfall and lower temperatures than other parts of Africa. These habitats are mountainous regions, where individuals can be found from sea level to 2000 m above sea level. (Bauer, et al., 1994; Moehlman, et al., 2015)

  • Range elevation
    0 to 2000 m
    0.00 to 6561.68 ft

Physical Description

Both African wild asses and domestic donkeys have a shoulder height range between 110 and 140 cm. The mass is not often reported but Piccione et al. (2008) reported the average mass of 5 adult females as 320 +/- 15 kg. The foal birth weight range is from 20 to 34 kg. Males and females are alike in their size, weight, and coloring. Their hair is longer on the dorsal end of their body. Their hair differs from the texture to the length. Their coat color is mainly a shade of gray, but the fur is white on their underbelly, muzzle, ears, around the eyes, inside the ears, and on the legs. They have a dark dorsal stripe and have black, horizontal stripes on their legs. The coloring is the same for both the juveniles and adults. Donkeys have a metabolic rate of 164.92 cm3 oxygen/hour. The dental formula is 313(4)3/3133, with tooth totals varying from 40-42.

They have small hooves that allow them to navigate around the rocky areas. It also allows them to have steady footing when traveling in the mountains. (Dadarwal, et al., 2004; Grinder, et al., 2006; Piccione, et al., 2008)

  • Sexual Dimorphism
  • sexes alike
  • Average mass
    250000 g
    8810.57 oz
    AnAge
  • Range length
    110 to 140 cm
    43.31 to 55.12 in
  • Average basal metabolic rate
    164.92 cm3.O2/g/hr
  • Average basal metabolic rate
    164.92 W
    AnAge

Reproduction

Donkeys are a polygynous species. Males will find their mates within their herds or find females who do not belong to a particular herd through pheromones given off by the females. The herds can differ in size, but a typical herd contains one male and ten females. Males often use visual and physical contact to attract a mate, but the most effective way has been through vocalization. The male will use the vocalization as a way to call to the females when he is ready to mate. The females will gain the males attention during estrus to ascertain interest. Females will raise their tails, spread their hind legs with their stomachs pushed down, open their mouths frequently while elongating their necks, and will kick at the males. When domesticated, females will often synchronize ovulation times and will mount each other when showing signs of estrus. The females would begin moving closer to the male during this time, as well. When ready to mate, males will begin to interact with the females in many ways. They will mount the females without the intention of breeding, sniff their genital area, smell the females' fecal matter, and nibble on different parts of the females' bodies. Males defend their mates from any intruding males by chasing them away. They keep the females, who are in estrus, a good distance away from those males. Sometimes when a male and female are about to breed, the other females in the herd will prevent them from doing so by kicking and pushing the male. When breeding actually occurs, the male begins by chasing after the female. After some time, the female will stop abruptly and push into the male. He will then mount her and complete the mating process. Not all of the females will get pregnant at the same time. Some may not end up pregnant after mating. Out of the females who do get pregnant, some may lose the foal. (Henry, et al., 1998; McDonnell, 1998)

Male donkeys do not reach sexual maturity until about 2 years of age but some can reach it as early as 9 months old. Some females are sexually mature at about 1.5 years of age but most females begin breeding around 2 years of age. Females are polyestrous and ovulate monthly from March through September. The gestation period is about 370 days. Females have one foal at a time but, on rare occasions, they can have twins. Foals have a birth weight range of between 20 to 34 kg. Before the foals are weaned, they follow their mothers and remain relatively close to them. Foals are fully weaned between 12 to 14 months after birth, which is when the mothers have another foal or can no longer provide food for them. When the foals are weaned, they become independent from their mothers. (Dadarwal, et al., 2004; French, 1998; Grinder, et al., 2006; Henry, et al., 1998)

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)
  • sexual
  • viviparous
  • Breeding interval
    Donkeys breed once yearly
  • Breeding season
    March through September
  • Range number of offspring
    1 to 2
  • Average number of offspring
    1
  • Average number of offspring
    1
    AnAge
  • Average gestation period
    370 days
  • Average gestation period
    359 days
    AnAge
  • Range weaning age
    12 to 14 months
  • Range time to independence
    12 to 14 months
  • Range age at sexual or reproductive maturity (female)
    1.5 to 2 years
  • Range age at sexual or reproductive maturity (male)
    9 months to 2 years

Female donkeys remain in close proximity to their foals for the first month. This is the period where the foals are nursing frequently. The physical distance the mother allows between mother and offspring slowly increases to about 10 m across the first year. This allows the foal to gain independence from the mother. For the African wild ass, many female foals remain with their mothers for their entire lives. Surrounding lone males will often steal females that have wandered too far from a leading male and create their own herd. The male offspring are kicked out of the herd by the leading stallion when they reach a year old. The males removed from the herd go out to start their own herds. The offspring of domesticated donkeys stay with their mothers their entire lives, building a stronger bond. When domesticated female donkeys sense a threat, they move closer to their offspring even beyond the first year. (French, 1998)

  • Parental Investment
  • female parental care
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female
  • pre-independence
    • provisioning
      • female
    • protecting
      • female
  • post-independence association with parents

Lifespan/Longevity

Domesticated donkeys have a maximum lifespan range from 47 to 50 years in captivity. In comparison, African wild asses can have a maximum lifespan of 29 years in captivity. There are no reports for lifespan in the wild. (Nowak, 1999; Weigl, 2005)

Behavior

Male donkeys are extremely territorial and defend the land they claim as theirs from other intruding males. Male African wild asses also fight each other over territories. They leave large fecal piles sporadically to delineate their territory. They maintain living in these areas but may move to another area with their herd if the amount of food has decreased exponentially. The leading adult male is the dominant figure of their herd but both male and adult females are dominant over the foals.

Donkeys mainly walk when they move around but, when threatened, trot or gallop away. When threats do occur, donkeys investigate the situation, before reacting, to determine if it is actually threatening or not. They are an active species and are active both the day and night. African wild asses and feral donkeys rest during the hottest parts of the day and forage for food when the temperatures are cooler.

Donkeys are a social species. Foals are known to be very playful and exhibit this in numerous ways. They can be seen running in random directions, jumping up and down, and kicking out. The adults will play with surrounding animals.

Male donkeys use vocalizations and physical contact to attract a mate for reproduction. Females use body language to gain the attention of the leading males during times of estrus. Donkeys will also demonstrate different types of communication to exhibit behavior. Their bodies are mainly used to demonstrate their moods by moving their ears and tails in certain ways. (Grinder, et al., 2006; Henry, et al., 1998; McDonnell, 1998; Moehlman, et al., 2015; Zola, 2009)

  • Range territory size
    97 (high) km^2
  • Average territory size
    32 km^2

Home Range

Donkeys have an average home range size of about 32 km2 but can have a range size as big as 97 km2. Females and males have been known to have the same range sizes. (Klingel, 1977; Woodward, 1979)

Communication and Perception

Donkeys and African wild asses communicate in the same way. They both use many different forms of communication. They use their body, sound, and smell to convey feeling. When using their bodies, they use their ears and tails to exhibit signs of their mood. Their ears can be pinned back to show anger, perked forward to show alertness, or one ear forward and one ear back to show curiosity. They will use their tail to show annoyance by swishing it back and forth quickly. Donkeys use a "hee-haw" sound that can travel up to 3 km away. These animals have a good sense of hearing that can detect these calls at such distances. They use physical contact to communicate with individuals in and outside their groups. Males are very territorial and other wandering males will try to take the territory to claim as their own. The males defending their territory will bite other males who pose a threat and have entered their territory to prevent them from taking the land. Members who are in the group will touch muzzles and lean against each other to display comfort. Their groups range in size, containing a few females, their offspring and a single male. They leave piles of dung to mark their territory boundaries. The females release pheromones to the alpha male when they are ready to reproduce. (Grinder, et al., 2006; Klingel, 1977; Moehlman, 2002; Moehlman, et al., 2015; Zola, 2009)

Food Habits

Donkeys are herbivores. Their teeth are used to grind and break off plants from their roots. The wide shape and blunt, shallow grooves of their molars help grind up the material and allows the food to pass into the stomach quicker and more efficiently. The particular food they eat depends on the time of year and the availability of the plant. Woodward and Ohmart (1976) found that donkeys consume a variety of grasses, forbs, and browsing plants in the United States during different seasons. Grasses are predominately consumed during the winter and spring months. The grasses include threeawn (Aristida), bush muhly (Muhlenhergia porter), and red brome (Bromus rubens). Forbs are mainly consumed during the spring, fall, and winter months. The forbs include wild buckwheat (Eriogonum), monkeyflower (Mimulus bigelovii), and evening primrose (Oenothera). Browsing plants are normally consumed during the spring and summer months. The browsing plants include catclaw acacia (Acacia greggii), white ratany (Krameria grayi), arrowweed (Pluchea sericea), and pricklypear (Opuntia). The food consumed year-round include fiddleneck (Amsinckia), desert Indianwheat (Plantago insularis), palo verde (Cercidium floridum), mesquite (Prosopis), and burro brush (Hymenoclea salsola). Arrowweed (Pluchea sericea) and mesquite (Prosopis) make up 50% of their diet. They do not travel more than 30 km away from a water source.

African wild asses eat similar foods as the domesticated donkeys. They eat various types of grasses, forbs, and browsing plants. (Bauer, et al., 1994; Grinder, et al., 2006; Woodward and Ohmart, 1976)

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

Predation

Domesticated and feral donkeys in the Unites states are hunted by coyotes (Canis latrans), red foxes (Vulpes vulpes), bobcats (Lynx rufus), mountain lions (Puma concolor), and black bears (Ursus americanus). African wild asses are hunted by humans (Homo sapiens), African lions (Panthera leo), and Ethiopian wolves (Canis simensis). Donkeys get into groups to reduce the risk of predation and to help keep their young safe. (Meade, 2015; Moehlman, 2002)

Ecosystem Roles

Donkeys are grazers and prey animals to many predators in their ecosystem. They have many parasites that they can contract that can endanger their survival. The different nematodes that affect them are Parascaris equorum, Cylicocyclus nassatus, Coronocyclus labratus, Oxuris equi, Cyathostomum tetracantum, Draschia megastoma, Strongloides westeri, and Dictyocaulus arnfieldi. Other types of parasites that have been known to harm donkeys are bloodworms (Strongylus vulgaris) and a species of fluke (Gastrodiscus aegyptiacus). (Ayele, et al., 2006; Hosseini, et al., 2009)

Commensal/Parasitic Species
  • Bloodworms (Strongylus vulgaris)
  • Cylicocyclus nassatus (roundworm)
  • Coronocyclus labratus (roundworm)
  • Oxuris equi (roundworm)
  • Cyathostomum tetracantum (roundworm)
  • Draschia megastoma (roundworm)
  • Strongloides westeri (roundworm)
  • Dictyocaulus arnfieldi (roundworm)
  • Parascaris equorum (roundworm)
  • Fluke (Gastrodiscus aegyptiacus)

Economic Importance for Humans: Positive

Domesticated donkeys are used as guard animals for livestock. Donkeys protect the animals from coyotes, red foxes, bobcats, and mountain lions that may harm or kill the livestock by chasing or kicking the unwanted predator. They are also used to help carry heavy loads for long distances, which aids humans in transporting goods.

African wild asses are killed for food and their bones are put into a soup to create a medical cure for many different human diseases. Moehlman et al. (2015) lists that the soup treats “tuberculosis, constipation, rheumatism, backache, and bone ache.” There is no scientific validation that the soup is a cure for any of the diseases listed. (Meade, 2015; Moehlman, et al., 2015; Yousef and Dill, 1969)

Economic Importance for Humans: Negative

Donkeys have been known to bite and kick humans. The majority of the injuries humans sustain from donkeys do not cause lasting damage. (Emet, et al., 2009)

  • Negative Impacts
  • injures humans
    • bites or stings

Conservation Status

Domesticated and feral donkeys are not listed as being endangered on any list. African wild asses are listed as being endangered by the U.S. Fish & Wildlife Service. They are also listed as being “Critically Endangered” by the IUCN Red List. They are listed in Appendix I on the CITES list. By being listed in Appendix I, this gives the African wild asses protection. People have to obtain a permit to move this species because they have to prove that they are able provide adequate care for African wild asses and intend to help their survival.

African wild asses are endangered because of the high amount of hunting. Hybridization between wild and domesticated forms has also been shown to threaten African wild asses because the hybridization is making the population become smaller in the wild.

In Ethiopia, African wild asses are legally protected. People cannot kill them for any reason and there are no ways around this law. Parks and reserves have been formed to help protect the species. Sudan also has laws that protect African wild asses and there are legal consequences for hunters. (Moehlman, 2002; Moehlman, et al., 1998; Moehlman, et al., 2015)

Other Comments

The common names of donkeys and African wild ass are used interchangeably in most scientific articles. There is a lot of disagreement as to whether the African wild ass is a subspecies of the domesticated donkey or if it is a completely different species altogether. At the time of the preparation of this species account, the donkey was classified as Equus asinus and the African wild ass was classified as Equus africanus.

Contributors

Rachael Pagan (author), Radford University, Cari Mcgregor (editor), Radford University, Zeb Pike (editor), Radford University, Karen Powers (editor), Radford University, April Tingle (editor), Radford University, Jacob Vaught (editor), Radford University, Genevieve Barnett (editor), Colorado State University.

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

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

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.
dominance hierarchies

ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates

drug

a substance used for the diagnosis, cure, mitigation, treatment, or prevention of disease

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.

female parental care

parental care is carried out by females

food

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

introduced

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

motile

having the capacity to move from one place to another.

mountains

This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

native range

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

nocturnal

active during the night

oriental

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

World Map

pheromones

chemicals released into air or water that are detected by and responded to by other animals of the same species

polygynous

having more than one female as a mate at one time

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

sedentary

remains in the same area

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

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

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.

References

Ali, M., M. Baber, T. Hussain, F. Awan, A. Nadeem. 2014. The contribution of donkeys to human health. Equine Veterinary Journal, 46/6: 766-767.

Ayele, G., G. Feseha, E. Bojia, A. Joe. 2006. Prevalence of gastro-intestinal parasites of donkeys in Dugda Bora District, Ethiopia. Livestock Research for Rural Development, 18/10: 1-3.

Bauer, I., J. McMorrow, D. Yalden. 1994. The historic ranges of three equid species in north-east Africa: A quantitative comparison of environmental tolerances. Journal of Biogeography, 21/2: 169-182.

Burden, F., A. Thiemann. 2015. Donkeys are different. Journal of Equine Veterinary Science, 35/5: 376-382.

Dadarwal, D., S. Tandon, G. Purohit, P. Pareek. 2004. Ultrasonographic evaluation of uterine involution and postpartum follicular dynamics in French Jennies (Equus asinus). Theriogenology, 62/1-2: 257-264.

Emet, M., N. Beyhun, Z. Kosan, S. Aslan, M. Uzkeser. 2009. Animal-related injuries: Epidemiological and meteorological features. AAEM, 16/1: 87-92.

Freeland, W., D. Choquenot. 1990. Determinants of herbivore carrying capacity: Plants, nutrients, and Equus asinus in northern Australia. Ecology, 71/2: 589-597.

French, J. 1998. Mother-offspring relationships in donkeys. Applied Animal Behaviour Science, 60/2-3: 253-258.

Grinder, M., P. Krausman, R. Hoffmann. 2006. Equus asinus. Mammalian Species, 794: 1-9.

Henry, M., L. Lodi, M. Gastal. 1998. Sexual behaviour of domesticated donkeys (Equus asinus) breeding under controlled or free range management systems. Applied Animal Behaviour Science, 60/2-3: 263-276.

Hosseini, S., B. Meshgi, A. Eslami, S. Bokai, M. Sobhani. 2009. Prevalence and biodiversity of helminth parasites in donkeys (Equus asinus) in Iran. International Journal of Veterinary Research, 3/2: 95-99.

Klingel, H. 1977. Observations on social organization and behaviour of African and Asiatic wild asses (Equus africanus and Equus hemionus). International Journal of Behavioural Biology, 44/3: 323-331.

Marshall, F., C. Asa. 2013. A study of African wild ass behavior provides insights into conservation issues, domestication processes and archaeological interpretation. Journal of Archaeological Method and Theory, 20/3: 479-494.

Matiuti, M., C. Matuiti, D. Dronca, E. Nistor, T. Mot. 2011. Research on donkey populations (Equus asinus) in Banat. Scientific Papers: Animal Science and Biotechnologies, 44/1: 286-290.

McDonnell, S. 1998. Reproductive behavior of donkeys (Equus asinus). Applied Animal Behaviour Science, 60/2-3: 277-282.

Meade, T. 2015. "Protect your flock with guard donkeys" (On-line). Accessed March 02, 2016 at http://www.hobbyfarms.com/livestock-and-pets/guard-donkeys.aspx.

Moehlman, P., F. Kebede, H. Yohannes. 2015. "Equus africanus" (On-line). The IUCN Red List of Threatened Species 2015: e.T7949A45170994. Accessed February 08, 2016 at http://www.iucnredlist.org/details/biblio/7949/0.

Moehlman, P. 2002. Equids: Zebras, Asses and Horses. Gland, Switzerland and Cambridge, UK: IUCN.

Moehlman, P. 1998. Behavioral patterns and communication in feral asses (Equus africanus). Applied Animal Behaviour Science, 60/2-3: 125-169.

Moehlman, P., F. Kebede, H. Yohannes. 1998. The African wild ass (Equus africanus): Conservation status in the horn of Africa. Applied Animal Behaviour Science, 60/2-3: 115-124.

Mueller, P., P. Protos, K. Houpt, P. Van Soest. 1998. Chewing behaviour in the domestic donkey ž / Equus asinus fed fibrous forage. Applied Animal Behaviour Science, 60/2-3: 241-251.

Nowak, R. 1999. Walker's Mammals of the World. Baltimore: JHU Press.

Piccione, G., F. Fazio, G. Caola, R. Refinetti. 2008. Daily rhythmicity in nutrient content of asinine milk. Livestock Science, 116/1-3: 323-327.

Ruffner, G., S. Carothers. 1982. Age structure, condition and reproduction of two Equus asinus (Equidae) populations from Grand Canyon National Park, Arizona. The Southwestern Naturalist, 27/4: 403-411.

Weigl, R. 2005. Longevity of Mammals in Captivity; From the Living Collections of the World. Germany: E. Schweizerbart'sche.

Woodward, S. 1979. The social system of feral asses (Equus asinus). International Journal of Behavioural Biology, 49/3: 304-316.

Woodward, S., R. Ohmart. 1976. Habitat use and fecal analysis of feral burros (Equus asinus), Chemehuevi mountains, California, 1974. Journal of Range Management, 29/6: 482-485.

Yilmaz, O., S. Boztepe, M. Ertugrul. 2012. The domesticated donkey: I - species characteristics. Canadian Journal of Applied Sciences, 4/2: 339-353.

Yousef, M., D. Dill. 1969. Energy expenditure in desert walks: Man and burro Equus asinus. Journal of Applied Physiology, 27/5: 681-683.

Zola, E. 2009. "Animal welfare: Animal communication" (On-line). Accessed February 11, 2016 at http://www.thedonkeysanctuary.ca/our-donkeys/animal-welfare-animal-communication.