Home-Range Analysis of the Endangered Roan Antelope (Hippotragus equinus langheldi) in Ruma National Park, Kenya
Keywords:
Adehabitat,, home range analysis,, roan antelopes,, Ruma National ParkAbstract
The roan antelope was formerly widely distributed in Africa but now its distribution range is so drastically reduced that the species is faced with the risk of extinction. In Kenya, only a remnant of less than 50 roans is left in Ruma National Park (RNP). Understanding the home range characteristics of this endangered species is a prerequisite for designing interventions for sustainable conservation. This study was carried out to investigate the differences and interactions of the home ranges of roan groups and lone males, determine the best home range estimator for the endangered roan antelope, assess various home range indices and characteristics of roan antelopes in different seasons and map the overlap of home ranges of roan groups and lone males in RNP. Data was collected on three roan groups and three lone males for six months using ground-tracking in RNP. Data analysis was done in the adehabitat package of the R statistical computing software using 3 home range estimators: minimum convex polygon (MCP), local convex hulls (LCH) and fixed kernel density (KDEhref). Results showed that mean ± S.E home-ranges (km2) for 95% levels were 6.01 ± 0.14, 4.64 ± 0.13 and 4.64 ± 0.16 for the roan groups and 3.14 ± 0.50, 3.35 ± 0.47 and 4.72 ± 0.49 for the lone males using MCP, LCH and KDEhref, respectively. The LCH produced more realistic home-ranges that aligned with park fences and omitted inaccessible steep areas. Analysis of wet and dry seasonal variation in home range characteristics showed no significant difference in home-ranges sizes, the distance travelled daily and average speed of movement. However, during the dry season roan groups significantly spread less (t = 4.399, df = 65, p < 0.0001) and had larger herd sizes (t = 5.073, df = 65, p < 0.0001) than in the wet season. These findings can help formulate a roan recovery conservation strategy with clear guidelines on habitat management.
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