Black Rhinoceros (Diceros bicornis) Fact Sheet: Reproduction & Development

Characteristic courtship behaviors

• Spraying
  • Males and females spray urine to advertise reproductive receptivity
  • See Olfaction/scent marking
  • See Olfaction/scent marking
• Cocking the tail
  • Females perform behavior when sexually aroused
  • Tail lifts and is cocked at an angle
• Making flehman
  • Males primarily exhibit this behavior
  • Similar to behavior in many other ungulate groups
  • See Olfaction/scent marking
• Dung scraping
  • Females behavior
  • Scrapes dung pile more energetically
    • Increases in scraping frequency and forcefulness
• Male follows estrus female for long distances
  • Effort an attempt to be accepted as a mating partner
  • Approach and following behavior
    • May follow calmly
    • Approachs with stiff, dragging legs
    • Exhibits "bluff and bluster" display
      • Male and female face each other nudging heads and jousting with horns
      • Not done with great force

Copulation

• Duration
  • Lasts for half an hour or more

Polygamous

• Males and females mate with more than one individual
  • Partnering can last from one mating session, to days, weeks, or sometimes months
• Males do not defend harems of females
  • Males do defend a receptive female by charging a potential competitor

Year-round reproduction

• No discreet breeding season

Estrus

• Duration
  • Lasts three days
  • Cycles every 25-30 days
• It can be difficult to tell when a female is in season
  • Changes in behavior provide clues
• It is also difficult to tell when a female is pregnant
  • May only become apparent few days before she gives birth

Gestation and parturition

• Gestation
  • 15-17 months, in the wild
  • 15-18 months, in managed care
• Age at first parturition
  • 3.5 to 5.7 years old
  • Varies group to group
  • Dependent on density and resource availability

Interbirth Interval

• Duration
  • 2.5 to 4 years

Birth

• Litter size
• 1 infant
• Birth weight
• 27 - 45 kg (59.5-99.2 lb)

Infant (< 1 year old)

• Development
• Begin solid foods in 7-10 days of birth
• Nibble on grass and small, non-woody plants

Immature

• Independent of mother at 2.5 to 3 years old
• Birth of new calf results in mother's rejection of the older sibling
• May find a non-related adult to join after being rejected

Adult

• Sexual maturity
• Reports of sexual maturity vary widely
• Females
• 3.5 to 4 years (Schenkel & Schenkel-Hulliger 1969)
• May conceive as young as 3.8 years (Estes 1991).
• Up to 7 years
• Males
• 6 years
• Fully grown at 8 to 10 years (Schenkel & Schenkel-Hulliger 1969)
• Up to 0 years (Estes 1991).

Managed care

• Diceros bicornis michaeli
  • Median life expectancy
    • 19 years (AZA 2023)

Environment

• Drought
• Somewhat vulnerable
• Survive better than many species
• New mothers and their calves are the most vulnerable
• Due to reduction in availability of nutritious food
• Pregnant females often abort their fetuses
• Malnutrition
• Kills an animal directly or  makes it more vulnerable to parasites and disease

Predators

• Uncommon cause of mortality
• Predators typically target sick or young individuals
• Potential predators
• Lion and hyena
• Attacks are rare

Exploitation by humans

• Primary cause of rhino death
  
• Poaching
• Highly vulnerable to hunting
• Black rhinos tend to revisit the same resting spots during the day

East African black rhino & calf at the San Diego Zoo.

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

Baby African black rhino born at the San Diego Zoo Safari Park in 2010.

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

Bertschinger (1995)
Estes (1991)
Goddard (1966 & 1967)
Hillman-Smith & Groves (1994)
Merz (1991)
Rookmaaker (1998)
Schenkel & Schenkel-Hulliger (1969)