Bovidae Author Don E. Wilson Author Russell A. Mittermeier text 2011 2011-08-31 Lynx Edicions Barcelona Handbook of the Mammals of the World – Volume 2 Hoofed Mammals 444 779 book chapter 58516 10.5281/zenodo.6512484 67b52095-db4b-43f8-a661-4aced0511111 978-84-96553-77-4 6512484 116. Sudan Reedbuck Redunca cottoni French: Rédunca du Nil / German: Sudan-Riedbock / Spanish: Redunca del Nilo Taxonomy. Cervicapra redunca cottoni Rothschild, 1902 , Kordofan. The Sudan Reedbuck was formerly classified as a subspecies of R. redunca . Monotypic. Distribution. Sudan , NE DR Congo , N Uganda , and far W Ethiopia . Descriptive notes. No confirmed measurements are available, but the Sudan Reedbuck tends to be several kilograms heavier than the neighboring Bohor Reedbuck ( R. bohor ), which it generally resembles. The pelage is pale golden brown with white underparts. A grayish stripe extends down the front of the forelegs, and is typically more prominent in males. Male Sudan Reedbucks are easily distinguished from other reedbucks by their long, thin, and widely diverging horns (females are hornless). Thin transverse ridges occur along most of the horn length; the tips curve inward, but do not form a strong hook. Typical horn length in mature males is 33-40 cm. The amount of divergence varies widely, averaging 30 cm between horn tips across the species’ range (general range 19-46 cm). However, individuals from the Mongalla area of Sudan may have a horn spread of up to 67 cm . The horns are, on average, 6 cm longer and with a spread 16 cm greater than those of the Bohor Reedbuck. Dental formula is 10/3,C0/1,.P 3/3, M 3/3 (x2) =32. Habitat. The Sudan Reedbuck inhabits grassy savannas and floodplains. Areas dominated by Hyparrhenia grasses are frequented during December (wet season); Oryza communities closer to deep swamps are used as the dry season progresses (through March). Average population densities across available habitat are generally 0-3-0-6 ind/km?, but localized densities of 63 ind/km* have been recorded during the wet season. Concentrations may reach 110 ind/km?® during the late dry season; the long horns of males are thought to correlate with increased competition resulting from sustained high population densities. Food and Feeding. The Sudan Reedbuck feeds primarily on grass; fecal analysis indicates the diet contains, on average, 88% grass, 9% forbs, and 3% shrubs. Species consumed include the sedge Cyperus laevigatus and Echinochloa grasses. Hyparrhenia grasses are also thought to be a principal food source, based on availability and the preferences of the related Bohor Reedbuck. Breeding. Breeding is likely seasonal, but remains poorly studied. Young have been observed accompanying adults in February (the dry season), and are likely born several months earlier. Other aspects are presumably similar to the Bohor Reedbuck. Activity patterns. There is no specific information available for this species, but presumably similar to the Bohor Reedbuck. Movements, Home range and Social organization. While some Sudan Reedbucks are resident in certain areas year-round, this species is generally migratory; seasonal movements are driven by changing water levels and vegetation abundance. During the rainy season, when forage is plentiful and water levels are high, the Sudan Reedbuck disperses across floodplains. At this time, the species tends to live alone or small groups of 2-5 individuals, although herds of 10-30 are also regularly seen. Average group size increases as individuals concentrate closer to permanent water sources during the dry season, when aggregations of over 100 animals have been recorded. During the dry season in Dinder National Park, Sudan , half of the reedbuck population may be found in these extremely large herds (up to 400 individuals). The Sudan Reedbuck uses the typical predator avoidance strategy of reedbucks: freezing in position, crouching low to the ground, or slowly retreating into cover when a potential threat is detected. Status and Conservation. Classified as Least Concern on The [UCN Red List (under R. redunca ). The Sudan Reedbuck is common in several localities and still occurs locally at high population densities. No complete population surveys have been performed recently, but numbers in southern Sudan are estimated at approximately 13,600 animals, with the majority (c.11,000) occurring outside of protected areas in the Jonglei area. Bibliography. East (1999), Fay et al. (2007), Hashim (1987), Holsworth (1972), IUCN/SSC Antelope Specialist Group (2008az), Kingdon (1982), Lydekker (1914), Wahungu (2006).