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.
Mating System: polygynous
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.
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 gestation period: 12 months.
Average weaning age: 5 months.
Average age at sexual or reproductive maturity (female): 2 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); viviparous
Average birth mass: 30000 g.
Average gestation period: 359 days.
Average number of offspring: 1.
Average age at sexual or reproductive maturity (male)
Sex: male: 1005 days.
Average age at sexual or reproductive maturity (female)
Sex: female: 708 days.
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.
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)
- Edwards, E., C. Geddes. 1988. The Complete Horse Book. North Pomfret, Vermont: Trafalgar Square Publishing.
- 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.
- Rachau, J. 1996. "The Donkey: Somewhat Defined" (On-line). Accessed October 3, 2000 at http://www.orednet.org/~jrachau/defined.htm.