|Microlivestock - Little-Known Small Animals with a Promising Economic Future |
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|Part V : Deer and Antelope|
Duikers (Cephalophus and Sylvicapra species) are small African antelopes. Although they are ruminants like cattle, sheep, and goats, some are hardly bigger than hares or rabbits. One, the blue duiker, is less than 40 cm high and usually weighs a mere 4-6 kg. It and some of the slightly larger duikers might be suitable for household husbandry because their meat is an extremely popular food throughout much of Africa. In West Africa, for example, it is one of the most common meats sold in both rural and urban markets.
This idea, however, is highly speculative because, despite their popularity, little is known about these tiny animals. Their husbandry has been attempted only a few times, but the results were encouraging, and rearing duikers deserves further investigation. They are already being raised in captivity in the United States,' Zimbabwe,2 Togo,3 and Gabon. Researchers in Nigeria have bred blue duikers to the fourth generation and found that, if the animals were first handled by people while young, they remained docile.4 Even blue duikers caught in the wild tame quickly if they are very young, but by the time they reach 3.5 months, they become barely tolerant of man's presence.
If duiker husbandry can be developed, it might provide not only a more regular source of meat, but also a lessening of the hunting pressures, thereby giving the wild populations a better chance of survival.
AREA OF POTENTIAL USE
These antelopes are suitable for testing as microlivestock only in their native region, sub-Saharan Africa. Eventually, they might prove to have wider applicability.
APPEARANCE AND SIZE
Duiker species vary from about the size of a small dog to that of a small donkey. Most are similar in shape and are characterized by short front legs, arched back, and pointed hoofs. The tail is stubby, often with a terminal tuft. The coat varies from reddish brown to nearly black, although a few species are blue-grey and one is zebra striped.
Females are slightly larger than males, but the sexes look alike. In most species, both sexes bear small straight horns that project backward from the skull, frequently hidden in a long tuft of hair.
Duikers inhabit virtually all regions of Africa below the Sahara— from Gambia in the west to Ethiopia in the east, and all countries as far south as South Africa.
Duikers are so shy that they are rarely encountered by people. But almost anywhere in Africa (other than North Africa), the observant traveler may glimpse them ducking into forests or thickets. Although there are still countless numbers, people are eating so many that in some localized areas the populations are fast heading toward extinction.
HABITAT AND ENVIRONMENT
All but one species are found in rainforests or dense woodlands. The grey duiker, however, is found in savannas. If the vegetation is juicy, only a few of the species need a separate water source, so they can thrive in very dry sites.
The main foods are fruits and seeds supplemented by leaves and shoots. Fruits, which they eat to a much greater degree than other antelopes, are an important part of their diet. Some rare species (for example, the red-flanked duiker, C. rufilatus) can graze. Occasionally (especially in captivity), duikers are also omnivorous, eating fish, crabs, insects, snails, frogs, small animals, or carrion; they also readily accept chopped meat.
Duikers reach sexual maturity at 9-15 months; gestation lasts about 7-8 months. In some species, females conceive a few days after calving on a 3- to 5-day postpartum estrus. Apparently one calf per birth is normal. A newborn blue duiker weighs between 0.4 and 0.7 kg.
Before one year of age, young duikers leave their parents to find their own mates and territories. Life expectancy is more than 10 years.
In spite of habitat differences, most duikers behave alike. In the wild they are nervous, shy, and retiring. When alarmed, they plunge into the protection of dense vegetation - hence the origin of the name duiker, which means "diver." Nonetheless, their behavior allows them to be easily netted. An experienced hunter can imitate duiker sounds and call the male out of the bush. Also, a startled animal freezes, thereby facilitating its capture.
Moving easily through dense vegetation, the head carried low, these tiny animals use regular runs. Forest duiker species are largely diurnal, although a few, such as the bay duiker, are nocturnal. Bush duikers are mainly nocturnal, feeding from early evening until morning. Such nocturnal species shelter during the day in holes (presumably dug by other animals) or inside fallen trees; the diurnal ones lie directly on the ground.
Blue duikers are the best-known species and are probably the most likely candidates for microlivestock (see page 332). They seem to be monogamous and apparently mate for life. Unlike most antelopes, their population densities can be high. The pairs reside in territories of 2-4 hectares, which both male and female stoutly defend against rivals. Other species appear to be polygamous and live in large territories (up to 80 hectares).
In captivity, the animals are generally calm. However, both males and females can be aggressive toward unfamiliar individuals of their own species. In an enclosure, one male can serve several females.
Large glands, located beneath each eye, exude a scent that is rubbed onto fences, trees, and other objects as territorial marking. In another form of marking the horns are rubbed against tree trunks.
As noted, duiker meat is much sought in many African countries, and the animals are regularly hunted. The meat is lean with little or no intramuscular fat (marbling).
Duikers also have promise as experimental animals. They are true ruminants, with four-part stomachs, and they produce cud. Some are only rabbit size, they need far less room or feed than sheep, and thus are potentially an efficient test animal for determining the nutritional value of forages. Blue duikers, for instance, have a digestion efficiency comparable to that of sheep, but, because of their small size, a test needs only four rabbit cages and 5-10 kg of feed. Sheep, by comparison, require much more spacious facilities and 150 kg of feed.
In Nigeria, blue duiker pelts are used in making karosses, a traditional dress. A single garment may contain up to 60 pelts.
Almost nothing is known about rearing duikers, but they seem to tame easily and perhaps may be kept in backyards like goats. Indeed, they reportedly make good house pets when hand raised. They are attractive, and from the day of capture young ones can be handled and petted.5
The Nigerian researchers who bred blue duikers to the fourth generation bottle-fed young specimens five times a day. Older animals were given feeds that included banana, plantain, and papaya; leaves of hibiscus, cassava, and banana; and dried corn. Variety seemed to be important, and the researchers could not predict the quantity of particular foods the animals would choose on any given day. In addition to varied vegetables, a small dish of salt or a salt lick was sometimes required.6
Duikers are unlikely to run away, except when startled. However, providing an enclosure is worthwhile. It enables them to establish a territory by marking poles, bushes, and fences. Although needing space in which to run, as little as 10 mÝ is reportedly sufficient for 24 animals.
Satisfactory shelters include an open-ended oil drum laid on its side, a lean-to made of palm frond, or a small hut made of local matting. Apart from providing shade and protection, shelters should be built so that excited animals can run through them. When cornered, duikers tend to either flee for shelter or jump upwards; a run-through shelter can prevent a frightened one from accidentally leaping over the fence.
Based on their own experiences, researchers at Pennsylvania State University in the United States report that blue duikers raised in captivity are easy to maintain, reproduce well, and are not fussy about environmental conditions. In fact, they say, blue duikers seem to enjoy living in cages.7
In order to raise duikers successfully, post-pubertal males must be separated. A female should be bred with the same male throughout her productive life span.
THE BLUE DUIKER
In one sense, the blue duiker is the most important animal in Africa. It is the only one found throughout the continent south of the Sahara. It occurs at a greater range of altitudes than most - as low as sea level in many places to almost 5,000 m elevation in Kenya. It occurs in habitats from dense rainforests to dryland savannas. And, in sub-Saharan Africa as a whole, the blue duiker is eaten more than any other animal (although in West Africa it is generally called Maxwell's duiker).
This very small antelope, caught by snare or net, can be found in the meat markets of villages, towns, and cities in all countries from Senegal to Madagascar. It is a source of food for tens of millions. Bushmen, Pygmies, Dinkas, and Mandingos, thousands of miles apart; all share the same fondness for duiker meat and for duiker-skin clothes.
Nevertheless, scientifically speaking, this is one of the world's least-known animals. And its numbers are diminishing rapidly. Areas that used to have plenty now have few or none. Overhunting and destruction of the rainforests are jointly contributing to their decline.
Despite the losses, people are snaring as many as they can, and there is no sense of concern - not even among most conservationists. However, in many locations there is already evidence that the animals won't be around much longer. Unless something is done - and soon - people will lose their major source of animal protein. If that happens, it is likely that they will move on to larger animals, such as gorillas, which would be an even worse disaster.
The best long-term solution is to organize duiker husbandry. Learning to rear duikers would benefit people throughout Africa. The blue duiker is the most suitable species; it is the most common and the most important. Also, it inhabits the edges of the forest and could therefore become a suitable species for ranching without denuding the forest.
Blue duikers are easy to maintain in captivity. They tame readily and like to shelter and sleep In boxes or cages. They are good converters of vegetation and produce top-quality lean meat. In addition, they are neither affected by tsetse flies nor are very susceptible to diseases.
The key now is to learn how to keep these very timid creatures under different conditions. We need to know their foods (especially foods that might be harvested from forests) and reproductive biology. We need to know the right numbers to house together. Most of all, we need projects aimed at rearing and breeding them in captivity under village conditions.
Vivian J. Wilson
Many African countries already have a ready market for duiker meat. It is somewhat similar to goat meat, but most people agree that it is superior.
The animal can live on fibrous vegetation. Unlike conventional ruminant livestock, it is suitable for feeding an average family at one meal.
The ability to forage in undergrowth where other domestic livestock do not thrive makes duikers potential livestock for tropical forest and bushland regions. They can be raised for meat without cutting the trees or bushes to create pastures.
Duikers are easy prey for predators: eagles, pythons, wildcats, and people, among others. Thus, they probably require more sophisticated management than common livestock such as goats. However, the quality of their meat could more than compensate for the extra effort.
Some species are territorial, which means that they may do poorly in captivity, unless their social organization can be altered.
Under good conditions, the ideal slaughtering age reportedly occurs at 8-10 months, when the blue duiker can weigh 4 kg. Compared to rabbits and guinea pigs, production is relatively slow because of long gestation and lack of multiple births.
Duikers are resistant to trypanosomiasis.
One general problem is that duikers have short, sharp horns designed specifically for jabbing. This could be a potential danger, especially since the males of some species become aggressive when their females are receptive. However, the horns can easily be clipped and taped to limit the danger.
RESEARCH AND CONSERVATION NEEDS
Because of the duikers' secluded lifestyle, much has still to be learned about their habits. Specific information on behavior and breeding is needed.
Animal scientists in Africa should gather small herds for comparative studies. This will provide insights into whether duiker temperaments facilitate or hinder their utilization. In addition, assessments of diet, growth rates, behavior in captivity, reproductive rate, adaptability, and future potential can be made. Management considerations include clipping horns, trimming hooves, and controlling lice and fleas.
Research of particular value would be chemical analysis of duiker milk and of other characteristic glandular secretions. The latter lend themselves especially to a study of animal communication.
Parming duikers might help rescue the wild populations by relieving hunting pressures. Programs in this area are recommended for locations where overhunting is occurring.