| Bohor reedbuck | |
|---|---|
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| Male bohor reedbuck inSerengeti,Tanzania | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Artiodactyla |
| Family: | Bovidae |
| Genus: | Redunca |
| Species: | R. redunca |
| Binomial name | |
| Redunca redunca (Pallas, 1767) | |
| Subspecies[2] | |
Subspecies list
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| Synonyms[2] | |
Thebohor reedbuck (Redunca redunca) is anantelope native to centralAfrica. The animal is placed under the genusRedunca and in the familyBovidae. It was firstdescribed by German zoologist and botanistPeter Simon Pallas in 1767. The bohor reedbuck has fivesubspecies. The head-and-body length of this medium-sized antelope is typically between 100–135 cm (39–53 in). Males reach approximately 75–89 cm (30–35 in) at the shoulder, while females reach 69–76 cm (27–30 in). Males typically weigh 43–65 kg (95–143 lb) and females 35–45 kg (77–99 lb). This sturdily built antelope has a yellow to grayish brown coat. Only the males possess horns which measure about 25–35 cm (9.8–13.8 in) long.
A herbivore, the bohor reedbuck prefers grasses and tender reed shoots with high protein and low fiber content. This reedbuck is dependent on water, though green pastures can fulfill its water requirement. The social structure of the bohor reedbuck is highly flexible. Large aggregations are observed during the dry season, when hundreds of bohor reedbuck assemble near a river. Males becomesexually mature at the age of three to four years, while females can conceive at just one year of age, reproducing every nine to fourteen months. Though there is no fixed breeding season, mating peaks in the rainy season. The gestation period is seven and a half months long, after which a single calf is born. The calves are weaned at eight to nine months of age.
The bohor reedbuck inhabits moist grasslands and swamplands as well as woodlands. The bohor reedbuck is native toBenin,Burkina Faso,Burundi,Cameroon,Central African Republic,Chad,Democratic Republic of the Congo,Ethiopia,the Gambia,Ghana,Guinea,Guinea-Bissau,Kenya,Mali,Mauritania,Niger,Nigeria,Rwanda,Senegal,Sudan,Tanzania,Togo, andUganda. The animal is possibly extinct inIvory Coast. Reckless hunting and loss of habitat as a result of human settlement have led to significant decline in the numbers of the bohor reedbuck, although this antelope tends to survive longer in such over-exploited areas as compared to its relatives. The total populations of the bohor reedbuck are estimated to be above 100,000. Larger populations occur in eastern and central Africa than in western Africa. TheInternational Union for Conservation of Nature (IUCN) rates the bohor reedbuck as ofleast concern.
Thescientific name of the bohor reedbuck isRedunca redunca. The animal is placed under the genusRedunca and in the familyBovidae. It was firstdescribed by German zoologist and botanistPeter Simon Pallas in 1767.[2] The three species ofRedunca, including the bohor reedbuck, are the leastderived members of thetribe Reduncini (except the genusPelea). The order of size in the genusRedunca is an evidence supporting the descent of the reduncines from a small ancestor.[3]
Fivesubspecies of the bohor reedbuck have been recognized:[3][4]
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The bohor reedbuck is a medium-sized antelope. The head-and-body length is typically between 100–135 cm (39–53 in).[5] Males reach approximately 75–89 cm (30–35 in) at the shoulder, while females reach 69–76 cm (27–30 in).[6] Males typically weigh 43–65 kg (95–143 lb) and females 35–45 kg (77–99 lb). The bushy tail is 18–20 cm (7.1–7.9 in) long.[5][7] This reedbuck issexually dimorphic, with males 10% to 20% larger than females and showing more prominent markings.[6][8] Of the subspecies,R. r. cottoni is the largest, whereasR. r. redunca is the smallest.[3]
This sturdily built antelope has a yellow to grayish-brown coat. Generally, the bohor reedbuck is yellower than other reedbucks. The large and diffusesebaceous glands present on the coat make the coat greasy and give it a strong odor.[9] Juveniles are darker than the adults as well as long-haired.[6] WhileR. r. bohor appears yellowish gray,R. r. wardi is richly tinted.[3] The undersides are white in color. A few distinct markings can be observed—such as a dark stripe on the front of each foreleg; white markings under the tail; and a pale ring of hair around the eyes and along the lips, lower jaw, and upper throat.[5][6] However,R. r. redunca lacks dark stripes on its forelegs.[3] The males have thicker necks. Its large, oval-shaped ears distinguish it from other antelopes.[10] There is a round bare spot below each ear.[6] Apart from sebaceous glands, bohor reedbuck have a pair of inguinal glands andvestigial foot glands, and fournipples.[9] A bohor reedbuck can survive for at least ten years.[8] The tracks of the bohor reedbuck are slightly smaller than those of thesouthern reedbuck.[11]
As a prominent sign of sexual dimorphism, only males possess a pair of short, stout horns, that extend backward from the forehead and hook slightly forward.[8] The horns measure about 25–35 cm (9.8–13.8 in).[5] However, some Senegalese individuals have longer and wide-spreading horns.[8] In comparison to the other reedbucks, the bohor reedbuck has the shortest and most hooked horns.[12] The longest horns are observed inR. r. cottoni, which are hooked less than normal and may curve inwards. In contrast toR. r. cottoni,R. r. bohor has short and stout horns, with hooks pointing forward.[3] The length of the horns of an individual of a certain region seems to be related to the population density in that region to some extent. While short horns are observed in individuals of eastern Africa, where populations are dispersed, longer and wide-spreading horns are found on animals in theNile valley, where populations are concentrated.[4]
The bohor reedbuck is host to severalparasites. The most notablehelminths found in the bohor reedbuck areCarmyerius papillatus (in therumen),Stilesia globipunctata (in the small intestine),Trichuris globulosa (in thecaecum),Setaria species (in the abdominal cavity),Dictyocaulus species (in the lungs) andTaeniacysts (in the muscles). Other parasites includeSchistosoma bovis,Cooperia rotundispiculum,Haemonchus contortus, species ofOesophagostomum,Amphistoma andStilesia. The commonticks found on the bohor reedbuck areAmblyomma species andRhipicephalus evertsi.[3]
Bohor reedbuck are active throughout the day, seeking cover during the daytime and grazing in the night. A large proportion of the whole day is spent on feeding and vigilance.[13] They can easilycamouflage in grasses and reeds, and hide themselves rather than running from danger.[8] When threatened, they usually remain motionless or retreat slowly into cover for defense, but if the threat is close, they flee, whistling shrilly to alert the others. It hides from predators rather than forming herds in defense. Many predators, includinglions,cheetahs,leopards,hyenas,wild dogs andcrocodiles prey on the reedbuck.[5]
If shade is available, females remain solitary; otherwise, they, along with their offspring, congregate to form herds of ten animals. Female home ranges span over 15–40hectares (37–99acres; 0.058–0.154 sq mi), while the largerterritories of males cover 25–60hectares (62–148acres; 0.097–0.232 sq mi). These home ranges keep overlapping. As the daughters grow up, they distance themselves from their mothers' home ranges. Territorial males are much tolerant; they may even associate with up to 19 bachelor males in the absence of females. As many as five females may be found in a male's territory. Territorial bulls drive out their sons when they start developing horns (when they are about a year-and-a-half old). These young males form groups of two to three individuals on the borders of territories, till they themselves mature in their fourth year.[8] Large aggregations are observed during the dry season, when hundreds of bohor reedbuck assemble near a river.[6]
Two prominent forms ofdisplay among these animals is whistling and bounding. Instead of scent-marking its territory, the reedbuck will give a shrill whistle to make the boundaries of its territory be known. As it whistles, it expels air through its nose with such a force that the whole of its body vibrates. These whistles, usually one to three in number, are followed by a few stotting bounds. This behavior is also used to raise alarm in herds. In this, the reedbuck raises its neck, exposing the white patch on its throat, but keeping the tail down, and leaps in a way similar to theimpala's jumps, landing on its forelegs. This is accompanied by the popping of the inguinal glands in the legs. Fights begin with both opponents holding their horns low, in a combat stance; followed by the locking of horns and pushing one another. These fights can even lead to deaths.[9]
A herbivore, the bohor reedbuck prefers grasses and tender reed shoots with high protein and low fiber content. This reedbuck is dependent on water, though green pastures can fulfill its water requirement.[6] A study of the bohor reedbuck's diet inRwenzori Mountains National Park (Uganda) revealed that, throughout the year, the most preferred species wasSporobolus consimilis. Other grasses the animals fed on includedHyparrhenia filipendula,Heteropogon contortus andThemeda triandra, all of which are species commonly found in heavily grazed grasslands. Bohor reedbuck preferredCynodon dactylon andCenchrus ciliaris in the wet season, and switched toSporobolus pyramidalis andPanicum repens in the dry season. Though they rarely feed ondicots, these can includeCapparis andSida species. On regularly burnt pastures, the bohor reedbuck feeds onImperata species, while in places close by water sources, it eatsLeersia and newly sproutedVossia species (liketopi andpuku).[3]
Primarily a nocturnal grazer, the bohor reedbuck may also feed at daytime. A study showed that feeding peaked at dawn and late afternoon. In the night, two feeding peaks were observed once again: at dusk and midnight.[14] They traverse a long way from their daytime refuges while grazing. Seasonal differences in the amount of time spent while grazing in a particular area is possibly related to the availability and quality of grasses there.[3] The bohor reedbuck often grazes in association with other grazers such ashartebeest, topi, puku andkob. In Kenyan farmlands, the reedbuck may feed on growing wheat and cereals.[8]
Males becomesexually mature at the age of three to four years, while females can conceive at just one year of age, reproducing every nine to fourteen months. Though there is no fixed breeding season, mating peaks in the rainy season.[9] Fights fordominance take place in some particular "assembly fields", where up to 40 males may assemble in an area of 1hectare (2.5acres; 0.0039 sq mi). Some parts of these grounds are the main attractions - marked with dung and urine. The reason behind the attractiveness of these few spots for sexually active males is theoestrogen in the females' urine.[4]
Courtship begins with the dominant male approaching the female, who then assumes a low-head posture and urinates. Unresponsive females run away on being pursued by a male. A male keen on sniffing the female's vulva keeps flicking his tongue. As they continue their "mating march", the male licks the female's rump and persistently attempts mounting her. On mounting, the males tries to clasp her flanks tightly. If she stands firmly, it is a sign that she is ready to mate. Copulation is marked by a single ejaculation, after which both animals stand motionless or a while, and then resume grazing.[6][9]
The gestation period is seven and a half months long, after which a single calf is born. The mothers keep their offspring concealed for as long as eight weeks. The mother keeps within a distance of 20–30 m (66–98 ft) of its calf. Nursing, usually two to four minutes long, involves licking the whole body of the calf and suckling. The infant is suckled usually once in the day and one to two times at night. The female's previous calf usually resists separation. At the age of two months, the calf begins grazing alongside its mother, and seeks protection from her if alarmed. Though after four months the calf is no more licked, it may still be groomed by its mother.[9] The calves are weaned at eight to nine months of age.[6]
The bohor reedbuck inhabits moist grasslands and swamplands as well as woodlands. It is found in two kinds of habitat in northern Cameroon: the seasonally flooded grasslands rich in grasses likeVetiveria nigritana andEchinochloa pyramidalis (in theSahelo-Sudan region) andIsoberlina woodlands (in the Sudano-Guinean region).[3] Often found on grasslands susceptible to floods and droughts, the bohor reedbuck can adapt remarkably well to radical seasonal changes and calamities.[15] It is not so widespread as thebushbuck due to its habitat requirements.[16] In some margins of its range, the bohor reedbuck shares its habitat with themountain reedbuck. The ranges of the bohor reedbuck and southern reedbuck extensively overlap in Tanzania.[3]
Endemic to Africa, the bohor reedbuck is native toBenin,Burkina Faso,Burundi, Cameroon, Central African Republic, Chad, Democratic Republic of the Congo, Ethiopia,the Gambia,Ghana, Guinea,Guinea-Bissau, Kenya,Mali,Mauritania,Niger, Nigeria,Rwanda, Senegal, Sudan, Tanzania andTogo. The animal is possibly extinct inIvory Coast andUganda.[1] Formerly widespread in western, central and eastern Africa, its present range extends from Senegal in the west to Ethiopia in the east.[17] Among the three reedbuck species, bohor reedbuck is the most widespread in Tanzania.[18] Its status in Burundi, Eritrea, Ghana and Togo is uncertain, while it is rare in Niger and Nigeria.[3]
Reckless hunting and loss of habitat as a result of human settlement have led to a significant decline in the numbers of the bohor reedbuck,[19] although this antelope tends to survive longer in such over-exploited areas as compared to its relatives.[17] Natural calamities, like drought, are also major threats. While populations have declined in northern Cameroon due to degradation of floodplains through the construction of upstream dams,[1] their habitat has been destroyed in Chad and Tanzania due to expansion of agriculture and settlement.[3] Several deaths occur due toroadkill and drowning as well.[3] During the dry season, bohor reedbuck are hunted with dogs and nets in Uganda. Reedbuck with the largest horns are prized by hunters.[6]
The total populations of the bohor reedbuck are estimated to be above 100,000. Though the populations are decreasing, it is not sufficiently low to meet thenear threatened criterion. Thus, the IUCN rates the bohor reedbuck as ofleast concern. Around three-fourths of the populations survive in protected areas.[1] Populations of the reedbuck are either declining or uncertain inBoucle du Baoulé National Park (Mali);Comoé National Park (Ivory Coast);Mole andDigya national parks (Ghana). Numbers in theAkagera National Park, where its last-known populations inRwanda exist, have seen a steep fall.[3]
Though populations have substantially decreased in western Africa, bohor reedbuck still exist inNiokolo-Koba National Park (Senegal);Corubal River (Guinea-Bissau);Kiang West National Park (Gambia);[20]Arly-Singou andNazinga Game Ranch (Burkina Faso). Larger numbers occur in eastern and central Africa, mostly in protected areas such asBouba Ndjida (Cameroon);Manovo-Gounda St. Floris National Park (Central African Republic);Bale Mountains National Park (Ethiopia);Murchison Falls National Park andPian Upe Wildlife Reserve (Uganda);Maasai Mara (Kenya);Serengeti National Park,Moyowosi-Kigosi andSelous Game Reserve (Tanzania).[17]
