Redunca chanleri (Rothschild, 1895)
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https://doi.org/ 10.5281/zenodo.6512484 |
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DOI |
https://doi.org/10.5281/zenodo.6636814 |
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persistent identifier |
https://treatment.plazi.org/id/03F50713-997E-FFC6-06DE-F714F813FEE1 |
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Conny |
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scientific name |
Redunca chanleri |
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Chanler’s Mountain Reedbuck
French: Rédunca de Chanler / German: Ostafrika-Bergriedbock / Spanish: Redunca de Chanler
Other common names: East African Mountain Reedbuck
Taxonomy. Cervicapra chanleri Rothschild, 1895 ,
mountains east of Kenia, British East Africa.
Chanler’s Mountain Reedbuck was formerly considered to be a subspecies of R. fulvorufula . Two forms have been described based on the presence or absence of a facial blaze, but these are no longer considered taxonomically distinct. This species is considered monotypic here.
Distribution. S Ethiopia, SE Sudan, E Uganda, W Kenya, and N Tanzania. View Figure
Descriptive notes. Head-body 110-136 cm, tail 20 cm, shoulder height 65-76 cm; mean weight for males 30 kg (22-38 kg) and for females 29 kg (19-35 kg). The soft, woolly coat is pale gray in color; females tend to be more drab in coloration than males. A line of sharp contrast separates the gray upperparts from the white underparts. When compared with the Southern Mountain Reedbuck ( R. fulvorufula ), the pelage of Chanler’s Mountain Reedbuck is paler and has very little reddish tint; the two species are otherwise quite similar. The bushy tail has a white underside; the dorsal surface of the tail is the same color as the back. The head tends to be more rufous than the body, and in some individuals is marked with a stripe of darker brown from between the eyes to the nose. The chin, lips, and upper throat are pale. A prominent glandular patch of bare black skin is found beneath each ear. Only males possess horns; the bases are ridged, and the tips have a slight forward curve. The horns typically grow 14-38 cm long, and are longer than those of the Southern Mountain Reedbuck. Dental formulais10/3,C0/1,P 3/3, M 3/3 (x2) = 32.
Habitat. Hillside savannas and thickets. Chanler’s Mountain Reedbuck inhabits broken, hilly country, where its sure-footedness and cryptic coloration serve to protect it from predators. Open, flat grasslands are used only reluctantly. Areas dominated by grasses such as Cynodon spp. are used for resting. Observations are generally from elevations above 1500 m, and this species has been observed at 5000 m on MountKilimanjaro, Tanzania. Throughout its high-elevation distribution, Chanler’s Mountain Reedbuck encounters a wide range of environmental extremes, including freezing temperatures and snow. Density estimates are 11-30 ind/km?, but this species may occur at up to 100 ind/km? in some areas.
Food and Feeding. Monocotyledonous plants compose, on average, 99-5% of the diet. Chanler’s Mountain Reedbuck feedsselectively, choosing soft, green grasses and avoiding dry grass leaves and stems. Preferred grass species are Themeda triandra, Hyparrhenia spp-, and Cymbopogon pospischilir. Other grass species are consumed less frequently, including Bothriochloa insculpta and Enneapogon schimperanus. The dominant grass within its habitat, Cynodon spp., is consumed in large quantities but far less than expected based on its relative abundance. Toward the end of the dry season (February and March), there is an increase in the consumption of leaves from shrubs and bushes. Two months after the rains set in, there is a notable drop in time spent feeding due to the flush of favored new growth.
Breeding. Chanler’s Mountain Reedbuck reproduces throughout the year, although a peak in births occurs in the March—May rainy season. Courtship resembles that of the Southern Mountain Reedbuck. A territorial male will approach individual females to ascertain their reproductive status; a female responds by stopping, lowering her head, and lifting her tail, allowing the male to smell and lick the vulva. Receptive females will typically urinate when stimulated, allowing the male to examine urine hormones by flehming. After moving several meters ahead, the female will stop again, and if she is in estrus the male will follow. Courtship progresses with stiff foreleg kicks directed between the hindlegs of the female, a ritualized precursor to mounting. Copulation is brief, and regular grazing activities resume shortly afterward. A single offspring is born after a gestation of eight months. Females experience a postpartum estrus as soon as 2—4 weeks after birth, but conception appears to occur only if the female has stopped lactating (i.e. lost her infant) at this time. Young females experience theirfirst estrus at 9-12 months of age; pregnancies have been recorded in several females approximately 18 months of age. Sexual maturity of males is less well studied, but sperm production starts at 8-12 months and young males are forced to disperse from their maternal groups by 15 months of age. Full maturity is likely to occur after two years of age as in the Southern Mountain Reedbuck. Maximum life span recorded in captivity 1s over twelve years.
Activity patterns. Active during the day and night, with patterns strongly influenced by temperature. Chanler’s Mountain Reedbuck is most active during cooler periods, especially while rain is falling. Diurnal activity occurs mainly in the early morning, when the reedbucks ascend hills, and late afternoon, when they descend. Activity levels are lowest at midday, with the decline beginning at 09:00 h and the lowest level reached around 12:00 h. This midday period is often spent resting in cover alongside the open grasslands at the bases of hills. Rumination is not closely tied to resting; indeed, there is a notable decrease in rumination rates during the hottest part of the day, particularly from 14:00 h to 17:00 h. From the late afternoon into the evening, activity levels rise. Nocturnal activity levels are generally higher; there are periods of reduced activity at 20:00 h and 01:00-03:00 h, but these are not as distinct as during midday. Valley bottoms are not used at night, presumably to avoid the areas where cold air settles. Throughout the day, males tend to be more active and less likely to lie down than females, which may be related to territorial defense.
Movements, Home range and Social organization. Chanler’s Mountain Reedbuck is most frequently observed in small groups. Females tend to live in small herds of 2-6 individuals, although groups of up to eleven animals have been recorded. Group size is smallest during May and June, the period following the birthing peak when females are tending to their offspring. Group structure is extremely fluid, and aggregations form and disperse based on feeding conditions. Males are territorial and tend to be solitary; they occupy exclusive home ranges and opportunistically join transient female herds. The mosaic of territories remains relatively fixed across time; 22 males observed in south-western Kenya occupied the same ranges for the duration of one seven-month study. Male territories are typically 0-02-0-05 km®. Higher-quality territories are smaller and more densely packed. Females frequently crossterritorial boundaries while foraging, but appear to prefer territories with high cliffs and increased bush level cover; female preference is not associated with food resources. Territorial males do nottolerate the presence of other males, and small bachelor groups of young males thus frequently form in marginal areas.
Status and Conservation. Classified as Vulnerable on The [UCN Red List (as R. fulvoru-Sula chanleri). The total population of Chanler’s Mountain Reedbuck is conservatively estimated to be 2900 individuals. Overall numbers are believed to be declining as a result of increasing human settlement and illegal hunting. The species’ status is unknown in Sudan and Uganda, and it is rare and highly localized within the Ethiopian Rift Valley. In Tanzania, most populations outside of extant protected areas are extremely endangered or extinct. Kenya remains the stronghold of Chanler’s Mountain Reedbuck, containing the majority of the population.
Bibliography. Dunbar & Roberts (1992), IUCN/SSC Antelope Specialist Group (2008ax), Irby (1977, 1979, 1982), Kingdon (1982), Roberts & Dunbar (1991), Weigl (2005).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
