West African Dwarf Crocodile
(Osteolaemus tetraspis tetraspis)
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.
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.
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, it is the Pacific Northwest Herpetological Society.
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.
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.