Dumeril's Boa
(Acrantophis dumerili)
Habitat
Dumeril’s
boas are found in the drier parts of Madagascar: the southern and southwestern
forests. Their pattern helps them hide effectively in the dry leaf litter
of the forest floor.
Length
and Weight
Dumeril’s boas reach an average length of 4-5 feet (1.21-1.5 m) and usually
weigh less than 20 pounds (9 kg).
The maximum recorded length is 7 feet (2.1 m). Females are larger than males.
Life
Span
20-30
years (estimate)
Diet
In the wild: Mainly
small mammals
At
the zoo: Domestic rats
Reproduction
As
with many other pythons and boas, a male Dumeril's
boa uses his "spurs" (the vestigial pelvic remnants adjacent
to his cloaca) to tickle and stimulate the female. If she is receptive,
she allows him to align his body with hers, opens her cloaca, and lets
him insert one of his paired copulatory organs, called hemipenes. Babies
are born alive about six to eight months later. Dumeril's boas
reach sexual maturity at about 3 to 5 years, males at an earlier age
than females.
Life Cycle
Probably because there are few large predators on Madagascar,
Dumeril's boas have smaller litters than other boa constrictors.
As a result, baby Dumeril's boas can be much larger. They are
large enough to avoid being eaten by the small predator species. These
snakes are independent from birth, and if they find enough food, they
grow very rapidly.
Boas and Pythons
Dumeril's boas and other Madagascar boas are relatives of Latin American
boas. Elsewhere in the Old World where big snakes are found, they are pythons
rather than boas. How did this strange distribution of boas occur? The answer:
plate tectonics. At one time, Madagascar, Africa, Australia, India, South America
and Antarctica formed a single continent called Gondwana. The relatedness of
the South American and Madagascar boas harks back to a time when boas were
probably the dominant big snakes throughout Gondwana. As Australia and Africa
approached the Eurasian land mass and were invaded by the different animals
which occurred there, pythons apparently "took over" and displaced
the boas. Some species of lizards found on Madagascar are in a similar situation—their
closest living relatives are also in South America, almost half a world away.
Hunting From Ambush
Like other boas and pythons, Dumeril's boas can lay virtually
motionless for long periods of time, waiting for an unwary prey animal
to pass. When in range, the boa strikes out in a single explosive motion,
using its many recurved teeth to grab hold of the prey and quickly
wrap it up in the coils of the snake's stout, muscular body.
Unable to breathe, the animal succumbs very quickly and is then swallowed
whole by the snake.
Location
at the Zoo
Currently, Woodland Park Zoo does not
have a Dumeril's boa on display. The Day/Night exhibit does have
many other species of snakes on display. A few examples of these
would be the boa constrictor, desert rosy boa and ball python.
Conservation
Connection
Dumeril's
boas are listed as an endangered species. Only about 10% of Madagascar's
forests remain, and they are being cut down and the wood burned or
used for constructing
houses. A number of conservation organizations are actively trying
to preserve wildlife and nature reserves in Madagascar. By joining
and/or contributing to them, you can help save Dumeril's boas
and other magnificent and unusual animals of Madagascar.
Dumeril's boas are kept off display. Woodland Park Zoo participates in
the Association of Zoos & Aquariums' (AZA) Species Survival Plan
(SSP) for Madagascar boas. Although Dumeril's boas are not on exhibit at
this time due to the lack of adequate exhibit space, we retain a number of individuals
behind-the-scenes as reserve animals that are part of the cooperatively-managed,
captive, self-sustaining zoo population. One day, with greater protection, these
animals or their decendants may be used to restock reserves in Madagascar.
How You Can Help!
The effort to save endangered species like the Dumeril's boa
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. Please
don't buy products made from wild animal parts. Let your elected
representatives know your views about protecting endangered species
and wild habitats.
Contact Woodland Park Zoo at webkeeper@zoo.org to find
out other ways you can support conservation programs at the zoo. Discover
more about snakes 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.
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.
Sources and Suggested Reading
Glaw & Vences. 1992. A Fieldguide to the Amphibians and Reptiles
of Madagscar. Published by the authors, Cologne, Germany. 331 p.
Mehrtens, John M. 1987. Living Snakes of the World. Sterling, New York, NY.
480 p.
Ross & Marzec. 1990. The Reproductive Husbandry of Pythons and Boas. Institute
for Herpetological Research, Stanford, CA. 270 p.
For Kids!
Markle, Sandra. 1995. Outside and Inside Snakes. MacMillian
Books, New York, NY. 40 p.
Resmick, Jane P. 1996. Eyes on Nature: Snakes. Kidsbooks, Inc., Chicago, IL.
29 p.
Zoobooks. 1992. Snakes. Wildlife Education, Ltd., San Diego, CA. 16 p.