Photo : Zim 4x4

Photo : Zim 4×4

Did you know – and I’ll bet you didn’t – that the Mana Pools National Park has its very own stretch of railway line?
Dick Pitman of Zim4x4 (self drive wilderness tours into the Zambezi Valley) didn’t either, until he saw it with his own eyes, in April and posted a picture to prove it.

This stretch of line really does exist, he says, albeit only two kilometers long and located in thick bush in the southern section of Mana Pools National Park near the Ruckomechi Research Station.

Could it be, he fantasized, a long-abandoned pilot study for the Mana Pools Light Railway Company, conducted in strictest secrecy and abandoned when tourism underwent one of its numerous slumps?!

The reality is somewhat more practical, it seems!

For decades, the Ruckomechi Research Station has been a Zambezi Valley base for research into tsetse flies (family Glossinidae), large biting flies similar to “horse flies” that inhabit much of mid-continental Africa between the Sahara and the Kalahari deserts. They live by feeding on the blood of vertebrate animals and can cause human sleeping sickness and animal trypanosomiasis, also known as nagana in domesticated animals (wild animals in areas inhabited by tsetse appear to have an in-built immunity to the disease).

Tsetse have been extensively studied because of their medical, veterinary, and economic importance.  John Davison tells us that this stretch of “trolley line” was linked to tsetse control research conducted by scientists under Dr Glynn Vale who studied the habits and behaviour of tsetse flies and how to control them.  Dr Vale is credited with inventing the modern tsetse fly trap which contains a chemical distillate smelling like ox breath which attracts the flies and then kills them with relatively little knock-on effect on their natural predators such as Robber Flies, which apparently catch tsetse on the wing like insect versions of Peregrine Falcons!.

Apparently wagons loaded with cattle were pulled up and down the trolley line located in the thick bush that attracts tsetse flies, while the researchers conducted experiments endeavouring to separate out the effect of “movement” from that of “shape, size or colour” with or without “odour”.  Interestingly, according to John’s brother Gerald Davison, a former Director of the Tsetse Control Branch, it was on this line that Dr Vale proved that both the human upright stance and odour were repellant to feeding tsetse flies, and that most of the following swarm of tsetse were in fact males, and were not interested in feeding at all.

Zim4x4 was shown the stretch of line by the owners of Kavinga Safari Camp, currently under construction a few kilometres away on the summit of a low cliff overlooking the broad Ruckomechi River, downstream of the tsetse research station and roughly 10km from the famous Chitake Spring.  The camp, once completed, will consist of five comfortable raised “tented lodges” and a central living/dining area and will offer guided wildlife and birding experiences in this untamed wilderness area.   Future visitors to Kavinga Safari Camp will certainly be surprised to come across this enigmatic (and historic) stretch of railway line in the middle of the bush during an afternoon excursion, and to learn about its origins!

Source : Wild Zambezi

12 June 2015