Plains Zebra (Equus quagga) Fact Sheet: Reproduction & Development

Stallion (male) mating behavior (from Klingel 2013 unless otherwise noted)

• Monitor excretions of group mares in estrus
  • Sniff mares' dung and urine, often while curling his lips
  • Deposit own feces or urine on top of that of mares; significance unclear

Mare (female) mating behavior (from Klingel 2013 unless otherwise noted)

• "Estrus face" and body posture indicate receptivity
  • Exaggerated, open mouth chewing; teeth partially bared, corners of mouth pulled up, and ears folded back

Copulation (from Klingel 2013 unless otherwise noted)

• Mare stands in front of stallion
  • She pushes backwards against him
• Multiple mountings and copulations occur during estrus

Year-round reproduction

• Foaling (birth) often concentrates within the wet season (Grubb 1981; Klingel 1965; Smuts 1976b)

Estrus

• Occurs shortly after foaling (Klingel 1965)
  • 8-9 days after birth; heat lasts c. 6 days (Smuts 1976b; Wackernagel 1965)
  • Interval between foaling and conception: 2-24 weeks (Grubb 1981)
• Indication of estrus
  • Marked by changes in stance and facial expression (see Courtship, above) (King 1965)

Gestation

• Duration
• c. 375 days; 360-396 days (Grubb 1981; Smuts 1976b; Wackernagel 1965)
• Development of male embryos may last longer than female embryos; c. 3 days (Wackernagel 1965)

Birth

• Typically in early morning
• Prior to sunrise (Wackernagel 1965)
• Full labor lasts 8-9 minutes (Grubb 1981)
  • Female lies on her side
  • Foal born head first (Klingel 2013)
• Litter size
• 1-2 foals; 1 most often as twins are extremely rare (King 1965; Smuts 1976b; Wackernagel 1965)
• Infant characteristics
• Weight at birth: 30-35 kg (66-77 lb) (King 1965)
• Coat pattern resembles that of the adult
• Stand within 11-13 minutes (Grubb 1981)
• Move about within an hour (Grubb 1981)

Interbirth interval (time between consecutive births)

• 371-385 days (Klingel 1965)
• Uncommon for mare to give birth yearly; < 15% of females observed in one 3 year study (Klingel 1965)

Infants (from Smuts 1976b unless otherwise noted)

• Protected by mother during first few weeks of life
  • Other zebras kept at a distance
  • Foal imprints during this time
    • Separation may result in foal imprinting on other individuals or even large objects such as a vehicle
• Play within a few hours of birth (Waring 1983)
  • Typical in equids (Waring 1983)
• Weaned within c. 9 months

Subadult (from Klingel 1965 unless otherwise noted)

• Colts (males)
  • Leave family groups at 1-3 years of age
  • Remain alone or join bachelor groups
    • Size of bachelor groups: up to 15
    • Smaller groups of males may remain together for extended periods, multiple years
• Fillies (females)
  • Abducted by non-familial stallions at 1-2 years of age

Adults

• Stallions
  • Sexually mature: 4-5 years of age (Grubb 1981; Smuts 1976c)
  • Mate only when a stable family unit is secured
    • Competition with older stallions for family breeding groups prevents earlier reproduction (King 1965)
• Mares
  • Sexually mature: 1-3 years of age (King 1965; Klingel 1965; Smuts 1976b)
  • First reproduce: c.3-4 years of age (Klingel 1965; Smuts 1976b)
    • Earlier ages possible, though atypical in the wild (Smuts 1976b)
  • Actively reproduce into old age (Smuts 1976b)
    • Pregnant 17-18 year old mares observed in one study (Smuts 1976b)

Managed care

• Median life expectancy
  • 16.9 years (AZA 2023)

Predation (from Grubb 1981 unless otherwise noted)

• Principle predator of adults
  • Lion (Panthera leo)
  • Stallions have highest rates of predator-caused mortality
• Other major predators
  • Of adults: spotted hyena (Crocuta crocuta)
  • Of foals: cheetah (Acinonyx jubatus), African wild dog (Lycaon pictus)

Disease caused by bacterial, viral, fungal, and protozoal infections (from Radcliffe and Osofsky 2002 unless otherwise noted)

• Bacterial diseases
  • Anthrax (Bacillus antracis) - infection by ingestion of spores, insect vectors
  • Brucellosis (Brucella abortus; B. melitensis) - infection by ingestion or inhalation
• Viral diseases
  • Rabies - contracted from infected mongoose, domestic dogs
  • African Horse Sickness (AHS)- contracted from fly vectors
  • Reovirus (Type 3) - contracted from arthropod vectors
  • Akabane Disease (AKA) - contracted from insect vectors
  • Equine Encephalosis Virus (EEV) - contracted from fly vectors
  • Equine Herpesvirus (EHV)
  • Wesselsbron Disease (WSL)
  • Equine Influenza (EI)
  • Equine Infectious Anemia (EIA)
  • Equine Arteritis Virus (EAV)
  • Bovine Herpesvirus-1 & 2
  • Malignant Catarrhal Fever (MCF)
  • Parainfluenza (PI-3)
  • Lumpsy Skin Disease (LSD)
  • Bovine Ephemeral Fever (BEF)
  • Bluetongue (BT)
  • Rift Valley Fever (RVF)
• Protozoal diseases
  • Sarcocystosis (Sarcocystis spp.) - ingestion of spores
  • Babesiosis (Babesia equi) - contracted from tick vectors
  • Toxoplasmosis (Toxoplasma gondii) - contracted from wild felid fecal contamination
  • Trypanosomiasis (Trypanosoma brucei rhodesiense) - contracted from tsetse fly vector
  • Besnoitiosis (Besnoitia bennetti) - unknown vectors

Males mature at older ages than females. Though a mare is capable of reproduction between the ages of one and three, a female typically gives birth to her first offspring at three to four years of age. Stallions mate only when they are able to secure a harem.

Image credit: © B Dupont from Flickr. Some rights reserved.

Duncan and Groves (2013)
Grubb (1981)
King (1965)
Klingel (1965)
Klingel (2013)
Radcliffe and Osofsky (2002)
Smuts (1974a)
Smuts (1976 b,c)
Wackernagel (1965)
Waring (1983)