Skip to Main Content
San Diego Zoo Wildlife Alliance logo
San Diego Zoo Wildlife Alliance Library logo

Guanaco (Lama guanicoe) Fact Sheet: Reproduction & Development


  • Male reproductive strategy is to defend a safe territory with high quality vegetation capable of attracting females
  • 3 basic social groups form during breeding season (Franklin, 1982)
    • Family harems
    • Non-reproductive male groups (immature males, yearlings evicted from family groups, and old or
      injured males)
    • Solitary males – not yet capable of attracting females and reproducing
  • Bands of adult females with young, move between male territories from middle to late mating season


  • Reproductive cycle coincides with best environmental conditions after rainy season
  • Ovulation is induced by copulation

Gestation and Birth


  • 11.5 months


  • Varies with latitude
    • North of Peru – April to June
    • Chilean Patagonia – Mid November to end of January
    • Coast of Northern Chile – Throughout the year
  • Concentration of births during a few weeks is an anti-predator strategy (pumas can only take a limited number of young)     


  • Weight: 7-15 kg (15-33 lb)
  • Single offspring – about 10% of mother’s weight.
  • Month varies with latitude.
  • In Patagonia nearly 80% of births occur during day (newborn dries faster).
  • Predation, starvation, weather, accidents can result in up to 70% mortality.


  • Exhibit “follower” behavior.
  • Able to stand 5-76 minutes after birth.

Life Stages

Infant (< 1 year old)

  • Forage intake begins 2-4 weeks.
  • Weaning at 3-4 months
  • Young stay with mother for 1 year (known as chulengos)


  • 1-2 years old.
  • Males forcibly ejected by territorial males, females remain.


  • Females reach sexual maturity at 2 years of age.
  • Males sexually mature at 3 years of age.
  • Males are unable to defend a territory until fully grown (3-4 years).

Typical Life Expectancy

Wild populations

  • Not well studied, but see survivorship curves and life table in Raedeke (1979)

Managed care

  • No AZA estimates

Page Citations

Gonzalez, et al (2006)
Franklin (1982)
Fowler (1998)

SDZWA Library Links