SINET: Ethiop. J. Sci., 34(1):39–48, 2011 © College of Natural Sciences, Addis Ababa University, 2011 ISSN: 0379–2897 CURRENT POPULATION STATUS OF THE ENDANGERED ENDEMIC SUBSPECIES OF SWAYNE’S HARTEBEEST (ALCELAPHUS BUSELAPHUS SWAYNEI) IN MAZE NATIONAL PARK, ETHIOPIA Wondimagegnehu Tekalign 1 and Afework Bekele 2 1 Department of Biology, Faculty of Natural Sciences, Wolaita Sodo University, PO Box 138 Wolaita Sodo, Ethiopia. E-mail: [email protected] 2 Zoological Sciences Program Unit, College of Natural Sciences, Addis Ababa University, PO Box 1176 Addis Ababa, Ethiopia ABSTRACT: A study on current population status, sex ratio and age structures of Swayne’s hartebeest (Alcelaphus buselaphus swaynei) was carried out during 2009/2010 in Maze National Park. Total count method was used in an area of 220 km2 using well trained park scouts based on silent detection. There were 372 individuals counted. The population trend indicates that there is a significant increase in the number of Swayne’s hartebeest population in Maze National Park at present. The sex ratio of adult males to adult females and young to adult females was 1:1.4 and 1:2.2, respectively. There is no significant difference between the sex ratio of males and females whereas there is a significant difference between young and adult females. Group size of Swayne’s hartebeest varied from solitary individuals to a maximum of 27. The difference among the groups is not significant. More solitary adult males were observed than solitary adult females. Swayne hartebeests were more associated with grassland with scattered trees (54%) than other three habitat types of the area, savannah grassland, bushland and riverine forest. There were no significant differences among the association of habitat types. Hartebeests were more associated to oribi (68%) than other ungulate species. There is an urgent need for further study to evaluate the actual threat of the endangered endemic subspecies of Swayne's hartebeests in Maze National Park. Key words/phrases: Endangered, Maze National Park, population status and structure, sex ratio, Swayne’s hartebeest INTRODUCTION were first named by Pallas in 1766. The very elongated faces are exaggerated by the bony Africa’s tropical savannas support the world’s extension or pedicle from which their horns grow most spectacular mammal fauna with large herds (Flagstad et al., 1999). Alcelaphus buselaphus was a of antelopes. The high degree of endemism is one widespread and variable species, ranging from of the reasons that made the African fauna so Senegal eastwards to Ethiopia and south to South interesting and spectacular (East, 1999). East Africa. At present, hartebeests are found only in Africa is noted for its diversity and abundance of parts of Botswana, Namibia, Ethiopia, Tanzania large mammalian herbivores. The Horn of Africa and Kenya (Batty, 2002). shows a great diversity of landscape and envi- Eight distinct Alcelaphus subspecies are ronment (Kutilek, 1979). The wide range of habi- recognized in Africa (Fig. 1). They are large sized tats in Ethiopia, from arid desert, open grassy antelopes in which males weigh between 120 and steppe, and semi-arid savannas to highland 228 kg and females on average 5–12% less than forests and Afro-alpine moor lands, support an males (Flagstad et al., 1999). The colouration of exceptionally diverse antelope fauna (Hillman, hartebeest varies dramatically between subspe- 1993). Ethiopia is one of the few countries in the cies, from light tan through bright rufous to deep world that possesses a unique and characteristic maroon. In addition, there may be blackish biota with high level of endemism (Jacobs and markings on the head and legs (Kingdon, 1997). Schloeder, 2001). However, due to man-made Hartebeests inhabit the savannahs and grass- and natural degradation processes, this wildlife lands of Africa and may occur in woodland or has largely been restricted to within a few scrub areas more than other Alcelaphines. conservation areas of the country (Hillman, Hartebeests are exceptionally tolerant to poor- 1993). quality food (Batty, 2002). Hartebeests (Alcelaphus buselaphus) are large African antelopes of the open grasslands. They 40 Wondimagegnehu Tekalign and Afework Bekele Alcelaphus buselaphus 1. A. b. buselaphus 5. A. b. swaynei 2. A. b. major 6. A. b. cokei 3. A. b. lelwel 7. A. b. caama 4. A. b. tora 8. A. b. lichtensteini Fig. 1. Distribution of different subspecies of hartebeests (Alcelaphus buselaphus) in Africa (Capellini and Gosling, 2007). Within a herd, there are territorial adult males, yellowish brown-collared rump colour along the non-territorial adult males, groups of young tail and lower half of legs (Bolton, 1973; Tischler, males, and groups of females and young. There 1975). The horns, which are present in both sexes, are strong dominance relationships between are particularly widely spread. Horn shape and females seldom fighting one another (Kingdon, growth vary with age, but at maturity, the horns 1989). Females and young may move in and out generally diverge widely from the pedicle and of the territories freely, looking for a better the points are usually turned back. Befekadu grazing area. Males lose their territory after 7 to 8 Refera and Afework Bekele (2006) described years (Kingdon, 1989; Batty, 2002). Both sexes Swayne’s hartebeest of Maze National Park with fight vigorously in defence of their offspring or several marked differences from that of Senkele territories. Hartebeests are social animals living Swayne’s Hartebeest Sanctuary. Most of the in organized herds of up to 300 in a herd (Batty, animals have a light fawn band running along 2002). They are very alert and cautious compared the top of their back from the rump to the base of to other plains ungulates. Hartebeests rely the head. Dark rib and hind leg patches do not primarily on sight to spot predators, and snort to occur in any of the animals. There is also regional warn each other from approaching danger. They difference in horn shape, flattened in Senkele move fast, may reach speed of 70 to 80 km/h one while circular in Maze, especially where the behind the other, after they see one of the horns emerge from the pedicle. members of the herd rushing away. Reproduc- Swayne’s hartebeests were widely distributed tion varies seasonally, but is perennial with 1 or 2 in Ethiopia and northern Somalia until the extended peaks depending on the population or beginning of the nineteenth century (Swayne, subspecies of hartebeests involved (Kingdon, 1899). At present, the population size has 1989; Batty, 2002). decreased and occurs only in four localities of In Ethiopia, three sub-species occur: A. b. lelwel, Ethiopia: Nechisar and Maze National Parks, A. b. tora and A. b. swaynei (Flagstad et al., 2000). Senkele Swayne’s Hartebeests Sanctuary and a Swayne’s hartebeest (Alcelaphus buselaphus smaller number observed in the vicinity of swaynei), locally known in Amharic as ‘Korkay’, Yavello (Messana and Bereket Netsereab, 1994; is the most attractive and colourful of the three Befekadu Refera and Afework Bekele, 2006). subspecies (Tischler, 1975). They are distin- Among the hartebeests, A. b. swaynei and A. b. guished from other hartebeests by the presence tora are classified as endangered and critically of darker body colour. It has a deep red chocolate endangered, respectively (Flagstad et al., 2000; brown or bright reddish brown with a fawn or Pascal et al., 2008). The overall objective of this SINET: Ethiop. J. Sci., 34(1), 2011 41 study is to assess the current population status from the southern parts of the surrounding and sex ratio and age class structures of Swayne’s highlands and passes through the Park in the hartebeests (Alcelaphus buselaphus swaynei) in north direction, and finally drains to Omo River. Maze National Park (MNP), Southern Nations The Park was established by the regional state in Nationalities and People’s Regional State 2005. It is about 485 km southwest of the capital (SNNPRS), Ethiopia. Addis Ababa via Wolaita Sodo-Sawla road. It is situated between 06°03' and 06°30' N latitude and 37°07' and 37°20' E longitude. The Park is MATERIALS AND METHODS surrounded by chains of mountains and bounded to the north by Quecha Wereda, to the The study area northwest by Omo River and Gofa Wereda, to The study was carried out in Maze National Park the west by Zalla Wereda, to the east by (MNP), which is located in Southern Nations Deramalo Wereda and to the south by Kemba Nationalities and Peoples Regional State, Wereda. The altitude ranges from 998 to 1200 m Ethiopia. The name of the Park is derived after above sea level and covers an area of 220 km2 the largest river called Maze River, which rises (Fig. 2). Fig. 2. Map of Maze National Park (Source: Maze National Park Office). 42 Wondimagegnehu Tekalign and Afework Bekele Rainfall at Maze (Morka area), although were designed based on natural and artificial continuous has a moderately bimodal pattern, boundaries, which act as barriers. There are four typical of semi-arid agro-ecological zone of vegetation types in the Park area: savannah Ethiopia. The annual rainfall varies between 843 grassland (SGL), grassland with scattered trees and 1321 mm. Maze area experiences a long (GST), bushland (BL) and riverine forest (RF). rainy season that extends from April to October Blocks 1 and 2 are mainly with SGL and GST, with the highest peak towards the end. The dry which are frequently burned by local community season is from November to February (NMSA while Blocks 6, 7 and 8 are mainly covered with 2001–2002 Meteorological data). The lowest BL and RF. Other Blocks (3, 4 and 5) are with the temperature recorded during the wet season was mixture of all vegetation types with the 15.3°C in June and the highest during the dry dominant of GST.