Common tsessebe

, South Africa Adult tsessebe typically measure in length. They are quite large animals, with males weighing and females , on average. Their horns range from for females to for males. For males, horn size plays an important role in territory defense and mate attraction, although horn size is not positively correlated with territorial factors of mate selection. The most significant difference between the tsessebe, the southernmost subspecies, and the other topi subspecies is the incline of the horns, with the tsessebe having horns which are placed further apart from each other as one moves distally. This has the effect of the space between them having a more lunate profile when seen from a certain angle, as opposed to lyrate, more like that of a hartebeest. Tsessebe populations show variation as one moves from South Africa to Botswana, with southerly populations having on average the lightest pelage colour, smallest size and the least robust horns. Common tsessebe do not differ significantly from the Bangweulu tsessebe, the northernmost population, but in general the populations from that part of Zambia are on average the darkest-coloured and have the most robust horns, although differences are slight and individuals in both populations show variation in these characteristics which almost completely overlap each other. ==Behavior==

Tsessebe are social animals. Females form herds composed of six to 10, with their young. After males turn one year of age, they are ejected from the herd and form bachelor herds that can be as large as 30 young bulls. Territorial adult bulls form herds the same size as young bulls, although the formation of adult bull herds is mainly seen in the formation of a lek. Tsessebe declare their territory through a variety of behaviors. Territorial behavior includes moving in an erect posture, high-stepping, defecating in a crouch stance, ground-horning, mud packing, shoulder-wiping, and grunting. The most important aggressive display of territorial dominance is in the horning of the ground. Another far more curious form of territory marking is through the anointing of their foreheads and horns with secretions from glands near their eyes. Tsessebe accomplish this by inserting grass stems into their preorbital glands to coat them with secretion, then waving it around, letting the secretions fall onto their heads and horns. This process is not as commonly seen as ground-horning, nor is its purpose as well known. Several of their behaviors strike scientists as peculiar. One such behavior is the habit of sleeping tsessebe to rest their mouths on the ground with their horns sticking straight up into the air. Male tsessebe has also been observed standing in parallel ranks with their eyes closed, bobbing their heads back and forth. These habits are peculiar because scientists have yet to find a proper explanation for their purposes or functions. ==Diet and habitat==

Tsessebe are primarily grazing herbivores in grasslands, open plains, and lightly wooded savannas, but they are also found in rolling uplands and very rarely in flat plains below above sea level. Tsessebe found in the Serengeti usually feed in the morning between 8:00 and 9:00 am and in the afternoon after 4:00 pm. The periods before and after feeding are spent resting and digesting or watering during dry seasons. Tsessebe can travel up to to reach a viable water source. To avoid encounters with territorial males or females, tsessebe usually travel along territorial borders, though it leaves them open to attacks by lions and leopards. ==Breeding and reproduction==

, South Africa Tsessebe reproduce at a rate of one calf per year per mating couple. Dominant males occupy the center of the leks, so females are more likely to mate at the center than at the periphery of the lek. ==Etymology==

The first known Westerner to record this antelope was the English painter Samuel Daniell, who painted it in "Boosh-wana", and recorded it as the "sassayby". The painting of the animal was first published posthumously in 1820 by his brother. William Cornwallis Harris, in his 1840 book about big game hunting, was quite familiar with the species in the Cashan Mountains and Kurrichane Hills, and renders the name as "sassaybe". Sassaby had thus become the common name for this antelope among European settlers living in Southern Africa by the end of the 19th century. The English later recorded the Setswana name for the antelope as tsessĕbe, by 1895 it was thought that this was the origin for the anglicised word. The proper Setswana name for the animal is Tshêsêbê. Other names for the antelope which were recorded by Frederick Selous around this time were inkweko in the language of the Basubia of the Caprivi Strip (related to Lozi), incolomo and incomazan in the isiNdebele of "Matebele", unchuru was the Sekuba name given by the Makuba of northern Botswana, inyundo by the Makalaka, and luchu or lechu by the Basarwa. The antelope was recorded as called myanzi in isiZulu and the bastaard hartebeest by the Afrikaners, indeed it looks somewhat like a cross between a hartebeest and a horse. The new vernacular name 'common tsessebe' was invented by Peter Grubb in 2005 to refer to Damaliscus lunatus lunatus to distinguish it from the new Bangweulu taxon. ==Conservation status==

In 1998, the IUCN estimated a total tsessebe population of 30,000, including the Bangweulu animals. It was assessed as 'lower risk (conservation dependent)'. In the 2016 update to the Red List of Mammals of South Africa, Swaziland and Lesotho, the minimum South African population was estimated as 2,256–2,803 individuals, of which the total minimum mature population size was 1,353–1,962; this was believed to be a significant underestimate, due to not getting enough responses from private game reserves on time for publication. During the 1980s and 1990s, tsessebe populations in South Africa and Zimbabwe declined significantly, especially in the National Parks. In 1999 the populations stabilised and began to grow again, especially in private game reserves. There were a number of different theories advanced as to what was causing this decline, while other species were doing well. A study compared the situation with around Lake Rukwa in Tanzania in the 1950s, a paper about game populations and the elephant problem, which might create the open habitat required through their bulldozing behaviour. ==Uses==

Excess tsessebe can be bought from South African National Parks via game auctions under Section 55(2) (b) of the Protected Areas Act 57 of 2003. In Zambia, Zimbabwe, Botswana, Namibia and South Africa, tsessebe may be legally trophy hunted in game management concessions, game ranches, or both. Tsessebe hides were formerly (1840) locally much in demand in South Africa to make a garment called a kobo, a type of leather mantle, both for the suppleness and the pleasing colour. The tail would be positioned at the back of the neck, like a ponytail, and would be opened and squeezed flat. ==References==