Przewalski's Horse (Equus ferus przewalskii) Fact Sheet: Reproduction & Development

Breeding behavior

• Stallions exhibit seasonal changes in sperm production and sexual behavior during spring and summer
• Social status and herd composition influence androgen hormone levels in males (D'Souza-Anjo et al. 2017)
  • Possibly affects male reproductive behavior

Mating

• Mare backs into stallion or stands in front of him to indicate receptivity
  • Ears turned back but not flattened, lips relaxed
  • May urinate
• Mounting
  • Stallion may rest chin on mare's back to test willingness to stand
    • Then rears and places his forelimbs in front of mare’s pelvis

Sexual Maturity

• Mare's first conception
  • At about 4 years of age
    • As early as 2 years of age
• Mares remain fertile until 20 years of age
  • 24 years of age is the record oldest age of giving birth
• Stallion testes do not descend until 2.5 to 3 years of age
  • Delayed descent is also observed in onagers, wild asses, and zebras
• Immature males may be incapable of breeding due to subordination to older stallions/males or incompetent sexual behavior.
• Stallions generally begin copulation at 5 years of age.
  • Continue copulation until over 30 years of age.

Estrus

• Seasonally polyestrous.
• In North America, cycles begin in early spring and last 7-8 months.

Reproductive rate

• 1 foal per year
• Mares conceive right after delivering a foal
  • Tend to wean the foal around 1 year
  • If fail to conceive, continue nursing for several years

Gestation

• Approximately 11 months (320-343 days)

Birth

• Mares ready to foal leave herd to seek quiet place.
• Return probably coincides with heat (9 days after birth).
• Birth weight:~30 kg (66 pounds)

Early growth and development

• Foal remains with dam for first 2 years
• Day 1
  • Stands, walks, trots
  • Nibbles forage
  • Neighs
• 1 week
  • Grazes: eats hay and grain
  • Solitary play
  • Defensive kicking
  • Eats adult feces
• 1 month
  • 39% of time resting
  • Begins playing with others in age group, older brothers and sisters
• 1 to 2 months
  • Nursing declines from 8.5% to 2.4%
  • Begins to leave mother’s side and interact with other foals
• 5-months
  • Spends same amount of time feeding as an adult, begin drinking water

Wild populations

• Not known

Managed care

• Median life expectancy

  • 17.9 years (AZA 2023)

A foal typically has a lighter coat color than an adult Przewalski's horse.

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

Asa (2002)
Boyd & Houpt (1994)
Klingel (1990)
Monfort et al. (1991)
National Geographic