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OCR for page 271
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Vizcacha
Vizcachasi (Lagostomus maximus) are soft-furred
South American rodents that look like long-tailed l - ]
guinea pigs. They can weigh as much as 8 kg and are t - ]
resilient animals, inhabiting dry pampas and shrub l'
lands in northern Argentina and neighboring countries. | |
They seem to have promise for producing meat and J 1
hides in marginal zones within their native habitat.
Like chinchillas (page 277), these rodents provide a prized furry
pelt. They also provide meat that reportedly tastes "as good as hare,"
which in Europe is considered the epitome of dining. They are easily
trapped alive in cheap, homemade, multiple-catch, funnel traps. And
they are thought to be suitable for farming on a large scale.
On the other hand, vizcachas are currently considered pests because
they take grazing from cattle and sheep and because they build large
burrows that undermine the land. Government campaigns have erad-
icated them in the richer agricultural areas of Argentina, but the animals
are still common in marginal zones. There is evidence that they become
more abundant when domestic livestock overgraze the land. In im-
proverished marginal sites, where other livestock enterprises are
unsuitable, the potential exists for game-ranching vizcachas.
AREA OF POTENTIAL USE
Because of the potential hazard to new areas, vizcachas can be used
only in the pampas regions of southern South America where they are
already widespread.
APPEARANCE AND SIZE
Vizcachas have short front legs, long, muscular hind legs, and round
' The common name is also spelled viscacha.
271
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272
MICROLIVESTOCK
Rio Cuarto, Argentina. In this area of central Argentina, vizcacha are common. One
slaughterhouse alone handles 10 tons of the animals weekly, and the meat can be bought
in any restaurant. (E.L. Marmillon)
eyes and ears. Their heads seem oversized in proportion to their
bodies. Males weigh 5-8 kg; females 2~.5 kg.
Members of the same rodent subfamily as the chinchilla, they have
a thick, soft, valuable fur that is gray or brown above, whitish or
grayish below. They are, however, much larger than chinchillas.
Although basically running animals, vizcachas often jump bipedally
(like kangaroos), and they sit erect while eating or grooming. The
forefeet have four long flexible digits used to grasp food. Their soles
and palms are naked and have fleshy pads (pallipes).
DISTRIBUTION
Vizcachas once swarmed widely over the savannas of southern
Paraguay, Bolivia, and Argentina, but they are being systematically
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VIZCACHA
273
exterminated. Today they inhabit isolated areas of north, central, and
western Argentina and southern Paraguay.
STATUS
Since 1907, these animals have been mercilessly hunted. The gov-
ernments of the Argentine provinces where they are mostly found,
reward hunters for killing this "pest." However, the numbers are so
reduced that now there is no need for a bounty system.
HABITAT AND ENVIRONMENT
Vizcachas live in flat, dry, steppelike plains; in dry woodland (Chaco);
and in low mountains.
BIOLOGY
The fact that these rodents eat their own droppings (coprophagy)
augments their ability to utilize natural forages, and allows them to
abound in degraded zones. They feed on any plant materials they can
find near their colonies, particularly grasses. In feeding trials, their
daily dry matter intake was 2-5 percent of the body weight. The
metabolic efficiency (dry matter per kg) was 33-56 percent; the digestive
efficiency was 5(}60 percent.2
Male vizcachas become sexually mature at about seven months of
age and remain fertile throughout the year. The gestation period is
long: 154 days. Litters contain one or two young. Newborns are well
developed, fully furred, and open eyed, although they cannot fend for
themselves for at least three weeks. In the wild, one or two litters are
reared each year.
BEHAVIOR
Vizcachas are nocturnal and are active year-round. They inhabit
underground burrows, living in colonies often containing many indi-
viduals. They collect a variety of materials (for example, bones, sticks,
and stones), and heap them in piles above the entrances to their
burrows.
Their hearing and sense of smell are acute.
2 Information from J.E. Jackson.
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274
Vizcacha's native range.
USES
MICROLIVESTOCK
-
Vizcachas have long been hunted for food as well as for their fur.
Their meat is often consumed in pickled form in southern South
America.
The skins are fabricated into table runners, rugs, bedspreads,
slippers, and belts. The skins are also popular for overcoats.
Vizcachas can be kept in captivity without major difficulty.
HUSBANDRY
In zoos, vizcachas are fed the typical diets furnished for vegetarian
rodents: rolled oats, green vegetables, bananas, apples, and bread.
They are usually kept indoors in wire-fronted cages, about 1 x 2 m in
size, and provided with sleeping boxes.
Little is known about vizcacha husbandry, but in one trial, weight
rose most rapidly in males until age 18 months (the average size was
then 5.3 kg) and subsequently slowed. The heaviest male was 7.3 kg
at 3~32 months. The female's weight gain was greatest until 1~18
months (average size 3.3 kg).3
3 Information from I.E. Jackson.
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VIZCACHA
ADVANTAGES
275
The animals seem well adapted to harsh sites where the climate and
forage make raising conventional livestock difficult.
The meat is white and has a good nutritive value because of its high
digestibility, low levels of saturated fats, and high levels of proteins.
In marginal zones of the pampas, these rodents appear far more
productive than traditional livestock.4
LIMITATIONS
Vizcachas may do considerable damage by foraging in cultivated
crops. As noted, ranchers claim that they take grazing away from
domestic animals, 10 Vizcachas eating as much as a sheep. In addition,
they claim, Vizcachas destroy pasture with their acidic urine. And the
large burrow systems sometimes create a hazard.
Because their reproductive rate is low and their growth rate is only
moderate, their commercial breeding might not be profitable except in
well-designed projects with clear markets.
Vizcachas require sturdy pens, which implies a high initial cost for
materials such as concrete and brick.
Vizcachas can be aggressive to one another, especially in captivity.
RESEARCH AND CONSERVATION NEEDS
There are several possible research projects,
including:
· Gathering specimens from different regions for comparative eval-
uation of characters such as biology, chromosome type, reproductive
physiology, social behavior (both in its wild state and under controlled
conditions);
· Attempting captive rearing and small-scale husbandry;
· Assessing performance under various environments; and
· Quantifying productivity and population dynamics in relation to
rangeland use and improvement practices.
A rational cropping program based on wild stocks is perhaps more
viable than captive breeding. This could be organized so as to keep
vizcacha numbers in check while sustaining a small chain of processing
plants by providing a constant supply of meat and skins.
4 Information from J.E. Jackson.
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Rock Cavy
Representative terms from entire chapter:
southern south
