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

Przewalski's Horse (Equus ferus)


  • Stallions exhibit seasonal changes in sperm production and sexual behavior during spring and summer
  • Mare backs into stallion or stands in front of him to indicate receptivity.  Ears turned back but not flattened, lips relaxed.  She may urinate
  • Mounting – stallion may rest chin on mares back to test willingness to stand, and then rear and place his forelimbs anterior to the mare’s pelvis.


Sexual Maturity

  • Mares first conception ~4-years.  (as early as 2 years)
  • Mares remain fertile until 20 years of age – 24 years is oldest recorded 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.


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

Reproductive rate

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

Gestation and Birth


  • Approximately 11 months (320-343 days)


  • 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)

Life Stages

Foals – Remain 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
  • 1-2 months – Nursing declines from 8.5% to 2.4%, Begins to leave mother’s side and interact with peers
  • 5-months – Spend same amount of time feeding as an adult, begin drinking water


  • About 20-25 years in managed care

Foals Most Fair

Przewalski's Horse foal

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

Image credit: © San Diego Zoo Global. All rights reserved.

Page Citations

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

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