Is the Tsetse fly not present in the game, or is this dev diary just listing a couple of the diseases present in game? (Reposting my old comment from the Tinto map thread for West Africa.)
Post in thread 'Tinto Maps #14 - 9th of August 2024 - Western Africa'
https://forum.paradoxplaza.com/foru...ust-2024-western-africa.1698675/post-29819084
Another facet of the disease discussion is that the tsetse fly made it impossible for the southern African states situated in the jungles to field much cavalry, unlike the the Islamic states of the Sahel like Mali or Songhai. The Oyo Empire was one of the few southern states to use cavalry to may meaningful degree, and that was largely because it held lands in the north and trading with other northern powers.
“Even such things as cattle and horses then, and still in many areas, will die in West Africa thanks to the Tsetse fly. None of this even touches things like Sleeping Sickness, Malaria, and a whole host of other diseases we never contemplate in the West today. All of these were much more common in West Africa than in Europe. Approximately, from the first establishments of Europeans as trading agents (1500s) until imperialism and the full conquest of Africa (late-1800s), at least 33% of all Europeans who went to Africa died there within 2 years -- depending on how you frame the parameters and if you narrow to just West Africa, that number becomes 50%. With the diseases and a climate so different from what they knew and loved in Europe, West Africa was hardly a place any European wanted to settle in, let alone en masse.“
“The Oyo Empire was one of the only Yoruba states to adopt
cavalry; it did so because most of its territory was in the northern
savannah.
[15]The origin of the cavalry is unclear; however, the
Nupe,
Borgu and
Hausa in neighbouring territories also used cavalry and may have had the same historical source.
[35] Oyo was able to purchase horses from the north and maintain them in metropolitan Oyo because of partial freedom from the
tsetse fly.
[36] Cavalry was the long arm of the Oyo Empire. Late 16th and 17th century expeditions were composed entirely of cavalry.
[15] There were drawbacks to this. Oyo could not maintain its cavalry army in the south but could raid at will.
[13][37] Despite its drawbacks, Oyo managed to amass one hundred thousand cavalry horsemen, earning the fear of many kingdoms and empires across West Africa.
[38]“
en.m.wikipedia.org