Seasonal movements and habitat use of African buffalo in Ruaha National Park, Tanzania.

BACKGROUND: Assessing wildlife movements and habitat use is important for species conservation and management and can be informative for understanding population dynamics. The African buffalo (Syncerus caffer) population of Ruaha National Park, Tanzania has been declining, and little was known about the movement, habitat selection, and space use of the population, which is important for understanding possible reasons behind the decline. A total of 12 African buffalo cows from four different herds were collared with satellite transmitters. Movements were assessed over 2 years from 11 animals. RESULTS: The space use of the individual collared buffaloes as an approximation of the 95% home range size estimated using Brownian bridge models, ranged from 73 to 601 km2. The estimated home ranges were larger in the wet season than in the dry season. With the exception of one buffalo all collared animals completed a wet season migration of varying distances. A consistent pattern of seasonal movement was observed with one herd, whereas the other herds did not behave the same way in the two wet seasons that they were tracked. Herd splitting and herd switching occurred on multiple occasions. Buffaloes strongly associated with habitats near the Great Ruaha River in the dry season and had little association to permanent water sources in the wet season. Daily movements averaged 4.6 km (standard deviation, SD = 2.6 km), with the longest distances traveled during November (mean 6.9 km, SD = 3.6 km) at the end of the dry season and beginning of the wet season. The shortest daily distances traveled occurred in the wet season in April-June (mean 3.6 km, SD = 1.6-1.8 km). CONCLUSION: The Great Ruaha River has experienced significant drying in the last decades due to water diversions upstream, which likely has reduced the suitable range for buffaloes. The loss of dry season habitat due to water scarcity has likely contributed to the population decline of the Ruaha buffaloes.

Health of African Buffalos (Syncerus caffer) in Ruaha National Park, Tanzania.

In association with a study investigating the apparent decline of African buffalos (Syncerus caffer) in Ruaha National Park, Tanzania, 40 buffalos were screened for selected diseases. Bovine tuberculosis was detected in 23%, and exposure to Brucella abortus and Rift Valley fever virus in 18% and 8%, respectively, of buffalos tested.

SCREENING FOR BOVINE TUBERCULOSIS IN AFRICAN BUFFALO (SYNCERUS CAFFER) IN NGORONGORO CONSERVATION AREA, NORTHERN TANZANIA: IMPLICATIONS FOR PUBLIC HEALTH.

In the Ngorongoro Conservation Area (NCA), Tanzania, where wildlife and livestock interaction is intense, greater potential for intra- and interspecies disease transmission is expected. We assessed the prevalence of bovine tuberculosis in African buffalo (Syncerus caffer) residing on the valley floor of the crater in the NCA. Apparently healthy animals were randomly selected from herds in nine sites of the Ngorongoro Crater. Syncerus caffer buffalo herds were located using very high-frequency radio-aided rangers positioned in various observation points around the crater in the NCA. A total of 102 African buffalo from 16 herds were immobilized from the ground using a cocktail of 4-10 mg etorphine hydrochloride (M99) and 60-150 mg azaperone tartrate. The M99 was reversed using 10-25 mg diprenorphine hydrochloride depending on age of animals. An interferon gamma assay was performed on harvested plasma samples using sandwich enzyme linked immunosorbent assay. Of the 102 animals sampled, two (2%) African buffalo tested positive for bovine tuberculosis. These results corroborate those of the skin test done recently in cattle in the NCA. The presence of bovine tuberculosis in livestock and wildlife suggested the possibility of cross-species transmission of the disease, indicating the need for appropriate intervention measures.

Profile of plasma lipids and degree of derangements among the elderly of Morogoro region, Tanzania.

Changes in lifestyles and ageing have been associated with growing rates of modifiable cardiovascular risk factors (CRF). Dyslipidemia is one ofthe CRF associated with numbers of cardiovascular diseases. This descriptive cross-sectional study was conducted to determine the profile and degree of derangements of plasma lipids among 300 (176 females and 124 males) elderly individuals aged ≥ 60 years in Morogoro, Tanzania. The calorimetric enzymatic methods and the Friedewal's equation were used for determination of cholesterols and triglycerides (TG). Social and demographic characteristics were gathered by structured questionnaires. The logistic regression models were used to identify the determinants of abnormal serum lipids level. Mean Total Cholesterols (TC) and Low Density Lipoprotein Cholesterols (LDL-C) in females exceeded significantly that of males. Mean TC, LDL-C as well as TG (mg/dL) declined significantly with age while mean High Density Lipoprotein Cholesterols (HDL-C) also declined but only slightly. Elderly females were two times more likely to have elevated TC (OR = 2.11; 95% CI: 1.04-4.28: P = 0.05) and LDL-C (OR = 2.15; 95% CI: 1.17- 3.97: P = 0.019) and three times to have lowered HDL-C (OR = 3; 95% CI: 1.97-5.30: P < 0.001) than males. Urban residents were about two times more likely to have elevated LDL-C (OR = 1.84; 95% CI: 1.04-3.25: P = 0.047) than their rural counterparts. Body Mass Index of ≥ 30 kg/m2 was also associated with elevated LDL-C (OR = 1.89; 95% CI: 1.05-3.42: P = 0.045) and lowered HDL-C (OR = 2.18; 95% CI: 1.3-3.65: P = 0.004), respectively. The present study has established the profile and level of derangements of serum lipids among the elderly of Morogoro region in Tanzania. It appears that, female sex and BMI of ≥ 30 kg/m2 are significant factors for elevated TC, LDL-C and lowered HDL-C while urban life is a significant factor for elevated LDL-C.