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

Hippopotamus (Hippopotamus amphibius) & Pygmy Hippopotamus (Choerpsis liberiensis) Fact Sheet: Summary

Hippopotamus (Hippopotamus amphibius) & Pygmy Hippopotamus (Choerpsis liberiensis) Fact Sheet


Hippopatamus (Hippopotamus amphibius)

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


Taxonomy Physical Characteristics

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Artiodacyla

Family: Hippopotamidae

Genus: Hippopotamus

Species: Hippopotamus amphibius - common hippopotamus

Genus: Choeropsis

Species: Choeropsis liberiensis - pygmy hippopotamus

Body Weight

Common hippo: males: 1,546 kg (3,408 lb), on average (up to approximately 2,065 kg, or 4,552 lb); females: 1,385 kg (3,053 lb), on average (up to approximately 1,850 kg, or 4,080 lb)
Pygmy hippo: about a sixth the weight of common hippo

Body Length

Common hippo: males: 300-505 cm (10-16.6 ft); females: 290-430 cm (9.5-14 ft)
Pygmy hippo: males: 157 cm (61.8 in); females: Up to 150 cm (59 in)

Tail Length

Common hippo: about 40 cm (16 in)
Pygmy hippo: 16 cm (6.3 in)

Common hippo: purple-gray or slate brown
Pygmy hippo: greenish-black above, grayish-white below

Distribution & Status Behavior & Ecology

Common hippo: sub-Saharan Africa
Pygmy hippo: mainly in Liberia

Common hippo: estuaries and rivers; reservoirs
Pygmy hippo: forests

IUCN Status
Common hippo: Vulnerable (2017 assessment)
Pygmy hippo: Endangered (2015 assessment)

CITES Appendix
Common hippo: Appendix II
Pygmy hippo: Appendix II

Population in Wild
Common hippo: 115,000-130,000 individuals
Pygmy hippo: Unknown; very roughly 2,000-3,000 for fewer adults remaining

Walk on river bottoms and on land; do not really swim. Charge with surprising speed.

Activity Cycle
Nocturnal. Common hippo pends day submerged in water. Pygmy hipps rests near water, but also on dry ground.

Social Groups
Gregarious. Typical herd size of common hippo is 10-15 individuals, but ranges from 2-50. Pygmy hippo is less gregarious, being solitary or found in pairs.

Grasses and other browse vegetation near rivers.

Humans. Nile crocodiles, hyenas, and lions, when young.

Reproduction & Development Species Highlights

Sexual Maturity*
Males: 6-13 years
Females: 7-15 years
*May be much younger in managed care

Common hippo: 227-240 days
Pygmy hippo: 188 days

Litter Size
One; twins rare

Interbirth Interval
If enough resources, able to give birth every year.

Birth Weight
Common Hippo: 25-55 kg (55-121 lb)
Pygmy Hippos: 5.73 kg (12.7 lb)

Age at Weaning
6-8 months (both species)

Typical Life Expectancy
Managed care: common hippo median life expectancy is about 37 years; pygmy hippo median life expectancy is about 28 years

Feature Facts

  • Hippopotamus essentially translates to the Greek for "river horse"
  • Whales are the hippo's closest living relatives
  • Special glands on a hippo's skin secretes mucous that protects them from sunburn, infection, and water loss
  • Low metabolic rate allows hippos to survive weeks without food
  • Jaws open wide; males use jaw-gaping and large tusks to compete for water-based territories
  • Mother–calf bond is very strong
  • Hippos mostly vocalize underwater
  • Keen sense of smell
  • Major threats to survival include habitat loss and hunting
  • Ancient Egyptians exhibited hippos in a private zoo 3,500 years ago

About This Fact Sheet

© 2011-2019 San Diego Zoo Wildlife Alliance. Population updated Feb 2019. CITES status updated Oct 2019.

How to cite: Hippopotamus (Hippopotamus amphibius) & Pygmy Hippopotamus (Choerpsis liberiensis) Fact Sheet. c2011-2019. San Diego (CA): San Diego Zoo Wildlife Alliance; [accessed YYYY Mmm dd]. hippopotamus
(Note: replace YYYY Mmm dd with date accessed, e.g., 2015 Sep 10)

Disclaimer: Although San Diego Zoo Wildlife Alliance makes every attempt to provide accurate information, some of the facts provided may become outdated or replaced by new research findings. Questions and comments may be addressed to

SDZWA Library Links