Dwarf Crocodile (Osteolaemus tetraspis) Fact Sheet: Summary

Kingdom: Animalia

Phylum: Chordata

Class: Reptilia

Order: Crocodylia

Family: Crocodylidae

Genus: Osteolaemus

Species: Osteolaemus tetraspis

Body Weight
Male: 18-45.4 kg (40-100 lb)
Female: 13.6-31.8 kg (30-70 lb)

Total Length
102-180 cm (3.3-5.9 ft); rarely exceeds maximum length of 200 cm (6.6 ft)

Tail Length
40-50% of total length

Sexual Dimorphism: No apparent dimorphism in body length exists between sexes. Adult males are typically heavier.

Other Features: Smallest crocodile species, typically much smaller than the maximum length of c. 2 m (6.6 ft). Both sexes may become quite bulky and wide. Proportionally more than doubles its weight for each 30 cm (1 ft) of growth in length between 91-182.9 cm (3-6 ft).

Range
Western & Central Africa, as far south as northern Angola and ranging to just east of the Congo River. Northernmost populations are found in southern Guinea-Bissau east to near Yobe, Nigeria.

Habitat
Small rivers and pools in forests and swampy regions. They require dense rotting vegetation to construct nests.

IUCN Status
Vulnerable (1996 assessment)

CITES Appendix
Appendix I

Population in Wild
Approximate number is unknown; abundant numbers in parts of Ivory Coast, Ghana, Gabon, Congo & Cameroon. Hunting and habitat loss is a threat in some areas.

Activity Cycle:  Nocturnal, hunting for prey at night and resting in the water during daylight hours.

Locomotion: Considered one of the most terrestrial of crocodiles, commonly venturing on land. Can "high walk," as is common with crocodiles. When swimming, will propel with the limbs (paraxial), tail (axial), and can use both simultaneously, producing a hybrid motion. Also uses the tail to propel the body vertically out of the water to ambush prey on overhanging tree branches.

Diet: Opportunistic predator with a varied diet, including millipedes, beetle larvae, fish, crabs, shrimp, reptiles, amphibians, birds and small mammals. Plant debris and rocks (gastroliths) are often found in the stomach. 

Interspecies Interactions:  Has a large degree of diet and habitat overlap with the Nile Monitor, which also preys on dwarf crocodile eggs and juveniles.

Courtship: Males produce drumming vocalization, often throughout the night, and partners will rub one another’s head and jaw. 

Nesting:  Mothers build mound nests of fallen leaves and rotting vegetation about 17 meters from the water and 1-2 meters above the water line. They guard and visit their nests.

Clutch Size:  Mean of 10-14 eggs, 6 - 17 observed.

Inter-clutch Interval:  Typically 1 clutch per season, annually

Incubation: c. 100 days

Growth:  Growth continues after reaching sexual maturity

Sexual Maturity:  Estimated maturity 6.8 – 15.7 years

Typical Life Expectancy: commonly survive > 40 years (according to ZIMS data)

Featured Facts

• Smallest crocodile species, typically reaching a maximum total combined body and tail length of c. 170-180 cm (5.6-5.9 ft).
• A mostly terrestrial crocodile, searches for prey along well-defined trails in the forest 
• Often observed in pools far from rivers
• Competes with other crocodiles but minimizes direct resource competition through habitat partitioning.
• Eight West African dwarf crocodiles hatched in November, 2017 at San Diego Zoo's reptile house, a first in the zoo's history.