The Plight of the Bushbucks: Losing By Conserving – Part 3

“Show me the data!!” reflects the always latent, and not so subtle, pathology of the scientist. The studies needed to define interactions between Bushbucks and Nyalas in Coutada 11 have yet to appear. So, we really can’t say right now whether Bushbucks lose out in the Zambeze Delta because of their more numerous relative. We can’t even say whether fewer Bushbucks run around Coutada 11 now compared to a decade ago – though the best guess from the experts on the ground in Coutada 11 is an affirmative answer for that question. What we can say from aerial surveys done most recently in 2019 is that there were 10-times more Nyalas seen than Bushbucks. Aerial surveys are not the best way to count cover-loving animals like Nyalas and Bushbucks. But, the fact that there were so many more Nyalas seen from the air than Bushbucks agrees with what everyone on the ground has noticed. Fortunately for this discussion, better data do exist to help understand the likely plight of the bushbucks in Coutada 11. These data come from a not-identical, but very analogous, situation in South African Conservation areas; the results are both complicated and cool.

Using hidden cameras, or at least hidden to Nyalas and Bushbucks, scientists in the Maputaland Conservation Unit looked to see when and where the two species showed up on pictures from the same cameras. Bushbucks were present since humans first walked through the area. Nyalas were a recent introduction. Using the photographic evidence, the scientists could see where the Bushbucks still occurred in the presence of their cousins, and where they had gone extinct. In general, the findings pretty much supported what the Zambeze Delta Safaris’ staff concluded from careful observation and intuition, but with some fascinating twists.

It was clear from both past population counts and the recent camera traps that Bushbucks were in trouble in the Maputaland Conservation Unit, and in fact had gone extinct in many areas they used to occupy. Even where they hung on, current numbers of Bushbucks in some areas were down to 10s of animals where a 100 years ago they numbered in the thousands. Each-and-every case of Bushbuck loss in the South African Conservation Areas occurred after the introduction of the way-better performing Nyala. But, the fascinating part – to a nerdy scientist – was that not all Bushbuck populations were going extinct when they overlapped with their beefier cousin. Why was this case? And, more importantly, could it outline a rescue plan for the declining Coutada 11 Bushbucks?

The scientists in South African Conservancies noticed two factors that gave the Bushbucks a fighting chance in the face of the Nyala incursion. In the first place, they observed that humans could limit the Nyalas ability to drive Bushbucks to extinction through so-called culling. This conservation management practice has come under serious attack by many who feel that nature will work population balances out if left alone. Others argue against the practice simply based on emotions, arguing that killing off scores of animals is barbaric. Regardless of the emotional heat generated towards culling, animals always have limited resources, and some, like overpopulated elephants and Nyalas do terrible damage to their habitats including other species that get in the way of their excesses…