Animal Fact Sheets

RANGE MAP

dwarf crocodile range map

WEST AFRICAN DWARF CROCODILE

  (Osteolaemus tetraspis tetraspis)


 

Classification and Range

The West African dwarf crocodile belongs to the family of crocodiles, Crocodylidae, which contains nearly all modern crocodilians (crocodile-like animals). The family Crocodylidae is divided into two subfamilies, Alligatorinae (alligators and caimans) and Crocodylinae (crocodiles). Dwarf crocodiles belong to the subfamily Crocodylinae. The dwarf crocodile (Osteolaemus tetraspis) is itself divided into two subspecies: The Congo dwarf crocodile (Osteolaemus tetraspis osborni) and the West African dwarf crocodile (Osteolaemus tetraspis tetraspis). The West African dwarf crocodile has a knob on its snout which distinguishes it from its Congolese cousin.

Habitat

West African dwarf crocodiles live in smaller bodies of water (ponds, creeks, backwaters) throughout West Africa.

Length and Weight

Books on crocodiles often say that dwarf crocodiles do not grow larger than about 5 feet (1.6 m) in length, but the male dwarf crocodile at Woodland Park is 6 feet, 3 inches (1.95 m) in length, and weighs 175 pounds (80 kg). Females tend to be much smaller, at only about 3-4 feet (.9-1.22 m) in length, and weigh far less than males. Our adult female weighs less than 40 pounds (18 kg).

Life Span

50-100 years (estimate).

Diet

In the wild:Mainly fish, but also frogs, birds, small mammals

At the zoo: Rats, mice, fish. Crocodiles often snap at things that splash near their heads. In this way, they easily catch their lunch in the form of a jumping frog, fish or bird that has selected a poor place to land. When zoo visitors throw coins at crocodilians, the animals may snap at and swallow the coins, and become ill.

Reproduction

Dwarf crocodiles become sexually mature when they are about 5 to 6 years old. The male approaches a floating female, slides onto her back and embraces her while attempting to align his cloaca with hers. If she is receptive, she opens her cloaca and he inserts his copulatory organ. Several weeks after mating, the female builds a nest from leaf litter. Here she lays five to 15 eggs, afterwards covering them with nest material. As with all crocodiles, she stays near the nest for the next several months, eating little or nothing while guarding the nest from predators, such as monitor lizards. When the babies begin to hatch, their vocalizations can be heard from outside the nest. The mother opens the nest and carries the babies to the water. She then guards them for several months.

Life Cycle

Even though they may have protection while they are small, newly hatched crocodiles must find their own food, first eating very small prey, like insects, small frogs and fish. If they manage to find enough to eat and avoid being eaten themselves, they can grow as much as a foot per year until they reach adult size

Protective Parents

Baby crocodiles make an “"urk, urk"vocalization when they are afraid, the same call that summoned their mother to help them from the nest. This distress call serves to summon the mother or even other adult crocodiles to rescue them from predators. The appearance of an outraged adult crocodile is usually enough to persuade any creature contemplating eating a baby crocodile to look elsewhere for its dinner.

Location at the Zoo

Woodland Park Zoo has a pair of West African dwarf crocodiles on exhibit in the Day Exhibit, where most of the zoo's reptiles and amphibians can be seen. They have produced 14 babies since they came to Woodland Park Zoo as young adults in 1973. Surviving offspring have been sent to zoos as far away as South Africa.

Conservation Connection

Dwarf crocodiles of both subspecies are endangered throughout their range. Habitat destruction, persecution and overhunting for their skins and meat contribute to their decline. All but a few of the world's 23 species of crocodilians are endangered.

Reptiles as Pets

We do not recommend reptiles as pets for most people as they require very specialized diets and environments. We also receive hundreds of requests each year to take former pet iguanas, boas and other reptiles but we cannot accept these due to space, health and unknown backgrounds. If you need to find a reptile or amphibian a new home, we suggest you contact a local herpetological group in your area.

In the Puget Sound region, contact the Pacific Northwest Herpetological Society as a resource. If you do choose to get a reptile as a pet, please learn as much as possible about their care and the best species before making your decision and never accept wild-caught animals as pets or release non-native reptiles or amphibians into the wild.

Contact Woodland Park Zoo at webkeeper@zoo.org to find out other ways you can support conservation programs at the zoo. Discover more about crocodiles by contacting the Society for the Study of Amphibians and Reptiles at 303 W. 39th St., PO Box 626, Hays, KS 67601. Learn other ways you can help conserve wildlife and the habitats they require for survival by visiting our How You Can Help page.

How You Can Help!

The effort to save endangered species like the dwarf crocodile requires cooperation and support at the international, national, regional and individual levels. You can help in this cause. Join and become active in Woodland Park Zoo and other conservation organizations of your choice. Please don't buy products made from wild animal parts. Don't buy baby “"alligators" which make poor pets.

Sources and Suggested Reading

Groombridge. IUCN Amphibia-Reptilia Red Data Book Part 1: Testudines & Crocodilians. IUCN, Surrey, UK. 426 p.

Neill, Wilfred T. 1971. Last of the Ruling Reptiles. Columbia University Press, New York, NY. 486 p.

Tryon, Bern W., in Murphy & Collins, eds. 1980. Reproductive Biology and Diseases of Captive Reptiles. Society for the Study of Amphibians and Reptiles. 277 p.

Webb, Grahame J.W. et al, eds. 1987. Captive Management of Alligators and Crocodiles. Chipping Norton, NSW, Australia. 552 p.

For Kids!

Matero, Robert. 1993. Reptiles. Kidsbooks, Inc., Chicago, IL. 29 p.

Zoobooks. 1995. Alligators and Crocodiles. Wildlife Education, Ltd., San Diego, CA. 19 p.

Dwarf Crocodile Taxonomy

Phylum: Chordata
Class:Sauropsida
Order:Crocodilia
Family:Crocodylidae
Genus:Osteolaemus
Species:O. tetraspis tetraspis

Dwarf Crocodile Fascinating Facts

  • Dwarf crocodiles do not attack humans. However, the large male here at Woodland Park Zoo has lost his fear of people and would almost certainly attack anyone entering his pool!
  • During the age of dinosaurs, there were crocodilians that grew to nearly 50 feet (15 m) in length. They preyed upon dinosaurs drinking at the water's edge, just as a modern Nile crocodile attacks and eats thirsty wildebeest at the waterhole!
  • Unlike other reptiles, crocodilians have four-chambered hearts. All other reptiles have three chambers in their hearts!
 
 
 
 

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