Distribution, abundance, and natural history of Lelwel Hartebeest on Lolldaiga Hills Ranch, central Kenya
Thomas M. Butynski & Yvonne A. de Jong, Lolldaiga Hills Research Programme
The Lelwel Hartebeest (or ‘Kenya Highland Hartebeest’) Alcelaphus buselaphus lelwel (Figures 1, 3, 4 & 5) is an ‘Endangered’ subspecies (IUCN 2016b). In Kenya, this subspecies is now primarily restricted to Laikipia County were only about 1,000 individuals remain (T. Butynski & Y. de Jong, in prep.). Hartebeest are strictly grazers that live in habitats dominated by grass, namely open and lightly wooded plains. They typically forage on short grass during the wet season and on long grass during the dry season in areas where drinking water is available (Gosling & Capellini 2013).
On Lolldaiga Hills Ranch (ca. 200 km²; ca. 1,700–2,300 m asl; www.lolldaiga.com), eastern Laikipia County, the altitudinal range known to be occupied by Hartebeest is ca. 1,750–2,100 m asl. The ‘Extent of Occurrence’ (IUCN 2016a) during August 2013–January 2019 was ca. 73 km², or ca. 37% of Lolldaiga Hills Ranch (hereafter, ‘Lolldaiga’; Figure 2).
Hartebeest were absent from Lolldaiga from at least 1960 until about 1982. Numbers peaked at about 100 individuals towards the end of the 1990s and remained at this level until around 2010 (Robert Wells, pers. comm.). The number of Hartebeest on Lolldaiga varied greatly from August 2013 through January 2019; there were as many as 35 individuals in 2014 but none during much of 2018 (Table 1). Thus, density within the ’Extent of Occurrence’ varied from no Hartebeest to 0.5 Hartebeest/km². These changes in numbers on Lolldaiga appear to be largely due to the fact that Hartebeest moved freely to the east onto and off of the contiguous Ole Naishu Ranch (ca. 125 km²) and Enasoit Game Sanctuary in the west (ca. 17 km²; Figure 2) as grazing conditions and the availability of water dictated. At least some of the change is, however, due to predation, as approximately 20 Lion Panthera leo, 30 Leopard Panthera pardus, 12 Cheetah Acinonyx jubatus, 200 Spotted Hyaena Crocuta crocuta, and three packs of Wild Dog Lycaon pictus used Lolldaiga during this period. All five of these species kill Hartebeest of all ages. Black-backed Jackal Canis mesomelas and Olive Baboon Papio anubis, both common on Lolldaiga, kill new-born calves (Gosling 1969; Gosling & Capellini 2013).
Table 1. Approximate range in the number of Lelwel Hartebeest Alcelaphus buselaphus lelwel on Lolldaiga Hills Ranch, Laikipia County, central Kenya, during each year from mid-2013 through January 2019.
|Year||Number of Hartebeest|
Size of Hartebeest herds on Lolldaiga during 20013–2019 ranged from 2 to 23 individuals. Mean herd size was ca. 8 individuals. The number of herds on Lolldaiga at any one time varied from none to three, and the number of lone adult males on territories ranged from none to two.
Twenty-five calves are known to have been born during this period. Calves that lack horns are <1 month of age (Gosling 1969). The monthly distribution of births is as follows: 5 in March; 7 April; 2 May; 1 June; 7 October; 1 November; 1 December; 1 January.
As such, there appears to be two birth seasons, both focused on the two wettest periods (March–May and October–November). Only one birth (January) was recorded for the two driest periods (January–February and July–September). This bimodal pattern of calving has also been documented for Coke’s Hartebeest Alcelaphus buselaphus cokii in Nairobi National Park (Gosling 1969). Calving at the start of the rains helps to ensure that there is abundant green grass and water during lactation and early weaning and, again, 7–8 months later when calves are fully weaned (Gosling 1969; Kok 1975).
A gestation of about 8 months (Gosling 1969) means that Hartebeest on Lolldaiga mate mainly during August–October and March–April.
We thank the follow for providing data used in this note: Mike Roberts, Robert Wells, Julius Mathiu, Paul Benson, Per Aronsson, Heather Wall, and Jim Wall.
References: Gosling, L. M. 1969. Parturition and related behaviour in Coke’s Hartebeest Alcelaphus buselaphus cokei Günther. Journal of Reproduction and Fertility (Supplement) 6: 265–286. Gosling, L. M. & Capellini, I. 2013. Alcelaphus buselaphus Hartebeest. In: Mammals of Africa, Volume VI. Pigs, Hippopotamuses, Chevrotain, Giraffes, Deer and Bovids. Kingdon, J. & Hoffmann, M., eds., pp. 511–526. Bloomsbury, London. IUCN. 2016a. IUCN Red List of Threatened Species. IUCN Species Survival Commission, IUCN, Gland, Switzerland. www.iucnredlist.org. IUCN 2016b. IUCN SSC Antelope Specialist Group, 2016. Lelwel Hartebeest Alcelaphus buselaphus lelwel. https://www.iucnredlist.org/species/811/50181009. Kok, O. B. 1975. Behaviour and ecology of the Red Hartebeest (Alcelaphus buselaphus caama). Nature Conservation, Bloemfontein, Orange Free State Provincial Administration, Miscellaneous Publication No. 5.
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