African Wild Ass (Equus africanus) & Domesticated Donkey (Equus asinus) Fact Sheet: Reproduction & Development

Courtship and access to females

• In arid climates
• Males control access to resources females need, like water (Moehlman 1998)
  
• Able to access females in estrus
  
• Grevy's zebras have similar mating systems
• In wetter habitats
• Donkey stallions have a harem of bonded females that he defends from outside males
• Horses and plains zebras also have this mating system (Moehlman 1998)
• Feral donkey mares in estrus outside a stallion's territory of may attract a number of stallions who fight but may all mate with her. (Klingel 1998)
• Receptive females stand with hind legs apart and tail held to the side. (Klingel 1998)

Mating sequence (Klingel 1998)

• Stallions sniff the female
• Female kicks towards him in a ritualized fashion and travels forward.
• Stallion follows, driving her for an average distance of 20 m (65.6ft).
  • Tame and feral donkeys and onager males all drive or chase the females a certain distance before mating
• When female halts, male mounts, and copulates.

• Females may be in estrus for up to 8 days. (Grinder et al 2006)
• Females in a group do not all come into estrus at the same time (Moehlman 1998)
• Peak breeding seasons vary in feral populations according to timing of wet/dry seasons. (Grinder et al 2006)

Gestation

•  1 year

Birth

• Female gives birth to one or two foals
• Weight of foals: 25 kg (55 lb)

Foal

• Can begin nibbling plants at 5 days when incisor teeth erupt (Moehlman 1998)
• Regularly browse on vegetation by 2 weeks, but depend on mother's milk for fluid (Moelhman 1998)
• Weaned at 12-14 months (Grinder et al 2006)
• At one year, foal still spends most of its time close to its mother (Grinder et al 2006)

Adult

• Sexual maturity for males by 2 years; can produce sperm earlier (Grinder et al 2006)
• Females reach sexual maturity at 1.5 yrs. but don't usually breed until 2-3 yrs (Grinder et al 2006)
  • Observed wild donkeys in U.S. deserts and reported females have first foals later, at age 3.5 to 4 years (Moehlman 2002)

Wild populations

• Averages about 20 years (Klingel 1990)

Managed care

• No AZA estimates

• Feral donkeys in U.S. face mountain lion and wolf predators
• Feral donkeys in U.S. subject to Wild, Free-Roaming Horse and Burro Act of 1971 (Grinder et al 2006)
• Law requires protection, management, and control of horses and burros on public lands
• National Park Service is exempt from this law and may remove burros dead or alive from its lands.
• Wild donkeys in Australia are culled by hunters in helicopters and on the ground.

Family of African wild asses, grazing.

Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.

Clutton-Brock (1992)
Grinder et al (2006)
Klingel (1990, 1998)
Moehlman (1998, 2002)
Nowak (1999)