• Mating season year round with peak at beginning of wet season

• Female estrus cycle: every 7.5 days; remain receptive only 8 hours

• One litter per year; two litters possible under good conditions

• Harem-based polygynous breeding (one dominant male, several females)

• Life span of male's sperm longer than that in most rodents; capybara mating system promotes sperm competition

• Group association essential for raising young; groups smaller than four adults fail to rear any young

• Gestation for 150 days

• 4 to 5 pups most common; a breeding group may have 15 pups or more at one time

• At birth young weigh about 1,500 grams (3.3 lbs)

• At birth, all cheek teeth already erupted, with signs of wear

Wild populations

• 7–10 years

Managed care

• Median life expectancy (AZA 2023)

  • Males: 7.1 years

  • Females: 8.6 years