Lechwe Research Articles

Diurnal activity budgets of red lechwe

Diurnal activity budgets of red lechwe

Mating system and ecology of black Iechwe (Kobus: Bovidae) in Zambia

The mating system and ecology of black lechwe Kobus leche smithemani was studied in the Bangweulu Basin, northern Zambia. Black lechwe were migratory and concentrated at high density during the wet season on shallow water floodplain and peripheral grassland. Female lechwe were evenly distributed in small groups within the two major habitat types, and density was related to water depth and the quality of vegetation. A proportion of the adult male population defended small, contiguous, resource‐based territories of approximately 1–2 ha in size. Particularly high density concentrations of male and female lechwe occurred on small raised areas, which remained dry in comparison to the inundated floodplain. These areas superficially resembled the leks of other reduncine antelope. However, the presence of vegetational resources and the comparatively low levels of agonistic and sexual behaviour suggested that raised areas were clusters of resource‐based territories. We suggest that the absence of lek‐breeding in this high density population of lechwe is related to the homogeneity of vegetational resources and the corresponding even distribution of females. This may have led to a reduction in male harassment of oestrous females and the increased ability of males to retain oestrous females within single resource territories.

Condition, growth and reproduction in male red lechwe (Kobus leche leche Gray 1850)

Summary Information on condition, growth and reproduction was collected from a sample of 85 male lechwe from the Linyanti Swamp in northern Botswana. No significant seasonal variation in condition was found in lechwe males. Von Bertalanffy equations were used to document growth in body-mass, body-length, chest girth, shoulder height, neck girth and horn length. Spermatogenesis occurred by 1.5 years of age after attainment of a body-mass > 55 kg, a testis-mass > 15 g and a semeniferous tubule diameter > 120 μm. There was an hiatus of perhaps three years between the onset of spermatogenesis and successful mating. In relation to condition, growth and reproduction, a number of sexual differences were documented, which were attributed to differences in the demands of reproduction and in reproductive strategies. Résumé On a récolté des informations concernant la condition physique, la croissance et la reproduction, sur un échantillon de 85 cobes lechwe máles des Marais de Linyanti, dans le nord du Botswana. Leur condition physique ne varie pas de façon significative avec les saisons. On a utilisé les équations de Von Bertalanffy pour relier la croissance à la masse corporelle, la longueur du corps, la circonférence de la poitrine, la hauteur au garrot, le tour de cou et la longueur des cornes. La spermatogenèse se produit vers l'âge d'un an et demi, lorsque le corps a atteint un poids de plus de 55 kgs, les testicules, de plus de 15 grs, et le canal séminal, un diamètre de plus de 120 μm. Il y a un délai de près de trois ans entre le début de la spermatogenèse et le premier accouplement efficace. On présente un certain nombre de différences sexuelles en relation avec la condition physique, la croissance et la reproduction, qui sont attribuées à des différences de demandes et de stratégies de reproduction.

Age- and sex-related differences in haematological values of the Lechwe waterbuck (Kobus Leche)

During an 8-year period (1981–1989), basic haematological values were evaluated in a number of clinically healthy Lechwe Waterbucks (Kobus leche) at five development stages. A total of 34 males and 60 females were used in this study.

A REVIEW OF DISEASES OF PARASITES OF THE KAFUE LECHWE (KOBUS LECHE KAFUENSIS)

The diseases of the Kafue lechwe (Kobus leche kafuensis) are reviewed in this paper. Kafue lechwe are an important natural resource for Zambia. Bovine tuberculosis is widespread within the lechwe population and they are host to many parasites, especially the warble Strobiloestrous vanzyli.

Condition, growth and reproduction in female red lechwe (Kobus leche leche Gray 1850)

SummaryInformation on condition, growth and reproduction was collected from a sample of 155 female lechwe in the Linyanti Swamp, northern Botswana. Condition varied significantly with age, reproductive state and season and indications were found of relationships between body mass and the attainment of puberty in young females and body mass and the fertility of adult females. There were also indications that the population was under nutritional stress because of high water levels and that this had caused reductions in the growth rate and fertility of young females.It is suggested that the sensitivity of young females to adverse environmental conditions could be exploited to optimize population monitoring for conservation purposes by using them as an indicator class, rather than monitoring the entire population. Because of relationships between condition, growth and reproduction, it is also suggested that long‐term monitoring of condition should form part of any effort to understand population dynamics.

The red lechwe of Busanga Plain, Zambia — a conservation success

When the Kafue National Park was established in 1950 the northern boundary was drawn to include the Busanga Plain, where there was a small population of red lechwe, much reduced by hunting. The effect of the protection was striking: numbers began to increase immediately and by 1973 there were 2000 individuals. In 1985 the authors conducted censuses to establish how the antelopes had fared in the intervening years. Their findings reveal just how successful the conservation measures have been.

Breeding season of the Lechwe Kobus leche

Breeding season of the Lechwe <i>Kobus leche</i>

Breeding season of the Lechwe Kobus leche

Breeding season of the Lechwe Kobus leche

Effects of Human Activities on Zambia's Kafue Flats Ecosystems

Hydroelectric dams have markedly altered the extensive floodplain of Zambia's Kafue River Flats. Before the dams were built in the 1970s, some 6,000 km2 of floodplain were under water for several months each year, permitting a dense growth of grasses and forbs that supported large populations of ungulates and waterbirds. Now a dam at the lower end of the Flats has permanently inundated parts of the floodplain, and a dam at the upper end has reduced the seasonal flooding, so that much of the floodplain is now probably permanently dry. When the Flats was revisited in 1983, the effect of the dams was obscured by the effects of drought, hunting, and human use.In 1983, plant growth in most places was much less luxuriant than it had been before impoundment. Bird populations seemed much smaller than formerly, and populations of at least some ungulates had declined. The most abundant ungulate, the Lechwe (Kobus leche), is reported to have declined by about half in the last eight years.

AERIAL CENSUSES OF SHOEBILLS, SADDLEBILLED STORKS AND WATTLED CRANES AT THE BANGWEULU SWAMPS AND KAFUE FLATS, ZAMBIA

Summary Howard, G. W. & Aspinwall, D. R. 1984. Aerial censuses of Shoebills, Saddlebilled Storks and Wattled Cranes at the Bangweulu Swamps and Kafue Flats, Zambia. Ostrich 55: 207–212. Aerial counts of three wetland species of uncertain conservation status were made in Zambia when the opportunity arose during Lechwe Kobus leche censuses. A portion of the Bangweulu Swamps was estimated to have a minimum population of 232 Shoebills Balaeniceps rex, 275 Saddlebilled Storks Ephippiorhynchus senegalensis and 1718 Wattled Cranes Bugeranus carunculatus. An estimate of 3282 Wattled Cranes on part of the Kafue Flats was very similar to that calculated in a count there nine years previously. Further censuses are recommended.

Schistosoma leiperi Le Roux, 1955 from a Bushbuck in Uganda

Schistosoma leiperi was first described by Le Roux (1955, Trans. R. Soc. trop. Med. Hyg. 49: 293-294), who noted that the adult worms, recovered from 21 species of herbivore, were rather small, but the eggs were large, resembling those of S. spindale, measuring 240 ,m x 45 ,m to 300 ,um x 60 ium. The type host of S. leiperi, as noted by Le Roux is the African antelope, the sitatunga (Tragelaphus spekei selousi) and the type locality is Mazubuka, Northern Rhodesia (=Zambia). It became later apparent that earlier reports of S. spindale in Africa probably referred to S. leiperi. In a checklist of definitive hosts exhibiting evidence of the genus Schistosoma acquired naturally in Africa, Pitchford (1977, J. Helminth. 51: 229-252) listed those of S. leiperi as follows: cattle in Zambia, East Caprivi and Tanzania; horse and sheep in Zambia; goat in Tanzania; African buffalo (Syncerus caffer) in Zambia and several species of antelopes in Zambia, Botswana and East Caprivi. It should be noted that the reports from Tanzania are from the southern region, close to Zambia. Pitchford (1976, J. Helminth. 50: 111-123) believed that cattle and the African buffalo are poor hosts for S. leiperi; that sheep and goats have hard, dry pellets and are not water-loving animals (presumably compared with species of the genus Kobus and Tragelaphus spekei), and thus may not be suitable hosts in nature, and that antelopes seem to be the best and the natural hosts. He earlier (1974, Rhod. Vet. J. 4: 57-61), reported eggs of S. leiperi in the feces of antelopes in the Chobe National Park, Botswana, namely the puku (Kobus vardoni), lechwe (K. leche), waterbuck (K. ellipsiprymnus) and reedbuck (Redunca arundinum). One pseudo-infection was reported in man in northern Zambia (Buckley, 1946, J. Helminth. 21: 111-174). The present paper reports on S. leiperi adult worms recovered from the liver of a bushbuck (Tragelaphus scriptus) in Uganda. The adult male worm measures 7.5 mm, and the female 9.5 mm. The in utero eggs measure 257.5 ,m x 45.5 ,m to 272.5 Am x 58.8 ,m. The worms and the eggs conform in morphology with that of specimens of S. leiperi from the mesenteric venules of a lechwe in Mazubuka, Zambia, the type locality of this schistosome species, given to the senior author by the late Dr. P. L. Le Roux of the London School of Hygiene and Tropical Medicine. The present report extends the geographical distribution of S. leiperi further north in Africa than previously known, and refutes Pitchford's (1976, J. Helminth. 50: 111-123) view of the restricted distribution of this southern African schistosome species. He stated that this species is limited to the region from Chobe game reserve in Botswana, through eastern Caprivi to Zambia, and also including the extreme western comer of Zimbabwe through to northern Zambia and southern Tanzania. We disagree with his statements in the conclusions and abstract that the restricted distribution of S. leiperi is due to the restricted distribution of the main definitive hosts, the lechwe (Kobus leche) and puku (K. vardoni); the poor host susceptibility of cattle and possibly Syncerus caffer, and the likelihood of most other game being unable to maintain the parasite indefinitely outside the confines of lechwe and puku distribution in southern Africa. He showed by maps the geographical distribution of some common game, other species of the genus Kobus, for example K. ellipsiprymnus and K. defassa, and this distribution extends further north, east and west than Zambia and the rest of the area of S. leiperi. As to the snail intermediate hosts, Le Roux (1955, Trans. R. Soc. trop. Med. Hyg. 49: 293294) reported that mice were exposed to cercariae from several naturally infected Bulinus africanus and adult S. leiperi were subsequently recovered. Moreover, Southgate et al. (1981, Z. Parasitkde 66: 63-81) found that snails of the Bulinus africanus group (B. africanus, B. globosus, B. hightoni and B. nasutus) were among those susceptible to isolates of S. leiperi from both Botswana and Zambia. The exposed snails included those from within, and those from outside the known area of distribution of S. leiperi. Among the susceptible snails from outside the

Census and population trends of black lechwe in Zambia

SummaryAn aerial census of black lechwe antelope was conducted in October 1983 as part of the long‐term monitoring of this species. Population size was estimated to be 41,401, a 64% increase since October 1973 when a similar type of count was carried out. The average rate of increase over this 10‐year period was about 5% year‐1–i. e. considerably less than the potential rate of increase, which is believed to be at least 20% year‐1. Subsistence hunting by the local people probably accounts for this difference. The need for regular monitoring of population size is emphasized.RésuméUn recensement aérien du lechwe noir fut mené en Octobre 1983 comme partie de l'étude à long terme de cette espéce. L'importance de la population est estimée à 41,401, soit une augmentation de 44% depuis Octobre 1973, où un type similaire de comptage fut entrepris. Le taux moyen d'augmentation sur cette période de 10 ans fut d'environ 5% par an; c'est beaucoup moins que le taux potentiel de croissance que l'on situe à 20% par an au moins. La chasse que mène la population locale pour sa subsistance explique probablement cette différence. La nécessité d'un contrôle régulier de la taille de la population est mise en évidence.

Basic haematological values in antelopes—III. The reduncinae and the antelopinae

1. 1. Basic haematological values were measured in 50 individuals of five species falling under the subfamily Reduncinae, including the mountain reedbuck ( Reduncula fulvorufula), the eastern waterback ( Kobus ellipsiprymnus ellipsiprymnus), the defassa waterbuck ( Kobus ellipsipyrmnus defassa), the lechwe waterbuck ( Kobus leche) and the Lady Gray's waterbuck ( Kobus megaceros) and in 45 animals of three species of the subfamily Antelopinae, including the springbok ( Antidorcas marsupialis), the Grant's gazelle ( Gazella Granti) and the dama gazelle ( gazella dama). 2. 2. The highest mean erythrocyte counts were found in the male springbok: 11.72 × 10 12/l, the lowest in the lechwe waterbuck: 8.39 × 10 12/l, the mean haematocrit values varied from 0.538 in the lechwe waterbuck to 0.443 in the defassa waterbuck and the mean haemoglobin content ranged from 181.2g/l in the male springok to 151.8g/l in the defassa waterbuck. 3. 3. Leukocyte counts were mostly shown to be in the human range, in the subfamily Reduncinae at the lower limit; only in the mountain reedbuck decreased values of about 3.5 × 10 9/l were demonstrated. 4. 4. These results are compared with information from the literature and with the normal human range.

Immature stages and affinities of the southern lechwe warblefly,Strobiloestrus vanzyliZumpt (Diptera: Oestridae)

Summary Eggs and first instar larvae of Strobiloestrus vanzyli Zumpt are described for the first time and it is suggested that there is a subdermal migration of the larvae from the site of oviposition on the hosts' hairs to the site of encystment and warble formation. Intrastadial morphological changes are reported for all larval instars and the descriptions of second and third stage larvae are enlarged. Wild caught adults and those reared from larvae extracted from lechwe antelope (Kobus leche) are compared with the published descriptions of Strobiloestrus species and with other specimens of this genus. The diagnostic features within the genus are discussed and it is concluded that S. vanzyli may not be a separate species from S. erikssoni. Strobiloestrus is considered in relation to other Oestridae, Hypodermatinae and Hypodermatini and it is suggested that this genus forms a distinctive group within the Hypodermatini but has some features in common with the Oestrinae.

Bilatorchis papillogenitalis n.g., n.sp. (Paramphistomidae: Orthocoelinae), a parasite of the red lechwe (Kobus leche Gray, 1850) from Zambia

Bilatorchis papillogenitalis n.g., n.sp. from the red lechwe, Kobus leche Gray, 1850, from Zambia is described and illustrated. It is assigned to the subfamily Orthocoelinae Price & McIntosh, 1953 and distinguished from other members of the subfamily by the lateral and symmetrical position of the testes in the posterior third of the body between the caecal ends and the acetabulum, the intertesticular position of the ovary and Mehlis' gland and the limited extent of the caeca which end only at the level of the anterior border of the testes. A new type of genital atrium, papillogenitalis type is proposed for B. papillogenitalis, Calicophoron papillosum, Carmyerius parvipapillatus and, possibly, Orthocoelium parvipapillatum. The genus Cochinocotyle Gupta & Gupta, 1970 is moved to the subfamily Orthocoelinae.

Observations on the life-cycle ofSchistosoma margrebowieiand its possible interactions withS. leiperiin Zambia

Summary Natural infections of Schistosoma margrebowiei were found in Bulinus forskali group snails (B. forskali and B. scalaris) at Lochinvar National Park, Zambia. This is the first record of a natural snail host for this species. The most abundant host in the Park for S. margrebowiei and S. leiperi is the lechwe (Kobus leche). Examination of a small sample of lechwe revealed that animals less than one year old had pure infections of S. margrebowiei and those over five years old had S. leiperi only. It is suggested that these findings are related to the different habitats occupied by the snail hosts for the two parasites and the annual movements of the lechwe herds in response to the local flood cycle. The possibility of some cross-immunity between S. leiperi and S. margrebowiei is discussed.

Bluetongue antibody in Botswana's domestic and game animals

Bluetongue precipitating antibody was demonstrated in sera of cattle, camels, sheep, goats and seven game species. Of the domestic species the percentage of sera positive were; cattle 92%, camels 81%, goats 83% and sheep 36%. Sheep sera, unlike those of other domestic species, varied greatly from area to area in the percentage positive. Seroconversions were recorded in adult sheep between September and April. In adult cattle there was a gradual decline in the percentage positive with increasing age. Positive reactions were recorded in the following game species: impala (Aepyceros melampus), lechwe (Kobus leche), kudu (Tragelaphus strepsiceros), blue wildebeest (Connochaetes taurinus), gemsbok (Oryx gazella), springbok (Antidorcas marsupialis) and tsessebe (Damaliscus lunatus).

Serological evidence of bluetongue in game animals in Botswana

Using the Agar Gel Precipitin technique the sera of 397 African buffalo (Syncerus caffer) and 90 sera of other common game species were examined for bluetongue antibodies. Of the adult buffalo 283 out of 325 (87 per cent) were positive. Buffalo calves were positive in 25 out of 72 cases (35 per cent). Positive reactions were also recorded in lechwe (Kobus leche), tsessebe (Damaliscus lunatus), red hartebeeste (Alcelaphus buselaphus), gemsbok (Oryx gazella), sable (Hippotragus niger) and impala (Aepyceros melampus).

Lekking Behavior in Kafue Lechwe

The Kafue lechwe (Kobus leche kafuensis) exhibits lekking behavior in which a number of males occupy small territories clustered together in discrete areas where females go for mating. Similar behavior in antelope is known only in the Uganda kob (Kobus kob thomasi). Lechwe lekking occurs only during a main rutting season although some breeding occurs throughout the year.