Why is the African Buffalo Population Declining in Tanzania’s Ruaha National Park?

By Annette Roug, for Safari Club International Foundation

The African buffalo population in Tanzania’s Ruaha National Park may be in decline.

Little is known about their ecology and health, but researchers from the Health for Animals and Livelihood Improvement (HALI) Project at the University of California, Davis and Sokoine University of Agriculture have partnered with Ruaha National Park to study the population in the hope of better understanding the decline.

As of September 2014, 30 young African buffaloes (Syncerus caffer) had been tested for bovine tuberculosis. The team from HALI and Ruaha National Park also conducted two dry-season demographic surveys and herd-level parasite screenings as well as an aerial population survey in collaboration with the Tanzania Wildlife Research Institute.

Research showed that bovine tuberculosis is present in the buffalo population, which appears to be reduced in animal numbers. Herd composition has varied from year to year and may be dependent on rain. The herd level gastrointestinal parasite counts were low.

But several questions remain unanswered.

“There is very little information about the buffalo home ranges, habitat preference, and seasonal movements,” said Annette Roug, a veterinary epidemiologist with the HALI Project. “Such information is important for understanding how the buffaloes use the ecosystem and its surrounding game reserves throughout the year.”

It will also help us determine which herds approach or cross the park borders, exposing them to increased risk for poaching and disease transmission between buffaloes and pastoralist livestock.

In 2014, the team was awarded a grant from Safari Club International Foundation to begin addressing these questions. That fall, the team conducted the third annual demographic survey of the buffaloes in the park and captured and collared 10 adult females.

During those surveys, two large herds and several smaller groups were encountered, some in the same areas as in 2011 and 2013. All herds appeared to be in good health and had low parasite loads.

Buffaloes were darted from vehicles, collared with a satellite GPS collar, sampled, and released. Only adult female buffalo were collared because the movement of female buffaloes is more representative of the herd movements, and females are less likely to damage the collars. A total of 10 buffaloes were sampled and collared across 4 different locations.

The satellite-based locations of collared buffaloes are being monitored remotely, and buffaloes are also located regularly to determine herd size, assess health and to record habitat preferences. As recently as February, the team located herds with collared buffaloes from a plane and from the ground.

The project has already provided a wealth of new information for Ruaha National Park. It is now clear that different buffalo herds inhabit distinct home ranges and for the first time the park has obtained information on wet-season movements. Collars will be monitored over the next two years and will help Ruaha conserve and manage the park’s buffaloes.

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