Why the Donkey Did Not Go South: Disease as a Constraint on the Spread of Equus asinus into Southern Africa

The constraining role of disease on the spread of domestic mammals in sub-Saharan Africa: A review

“…Donkeys, in contrast, mostly display subclinical signs, but outside Africa have been reported to exhibit mortality rates of up to 10% (Alexander, 1948). Along with the lack of any significant distributional overlap between zebras and those African wild ass (Equus africanus africanus) populations from which donkeys derive (Mitchell, 2017), might this hint that they too suffered from African horse sickness on first encounter before evolving the degree of immunity that they now possess? Finally, note that African horse sickness is also extremely dangerous to dogs, producing mortality rates of between 20% and 78% (Coetzer and Guthrie, 2004).…”

“…AD 75, Beta-1904888;Robbins et al, 2008) may, however, mean that what seems on the surface like a recurrence of the East African caprines-before-cattle pattern (Gifford-Gonzalez, 2016) is no more than an artefact of sampling. Donkeys, on the other hand, which were kept by some Pastoral Neolithic groups, did not make it south (Mitchell, 2017), not even when Khoekhoe pastoralists of ultimately East African origin were joined in southern Africa by agropastoralist Iron Age groups with both East and Central African roots (Huffman, 2007).…”

“…Palaeoenvironmental studies with implications for the prevalence of trypanosomiasis in East and southcentral Africa, and thus for the spread of livestock south of the Equator, have also recently appeared (Chritz et al, 2015;Robinson and Rowan, 2017). Other papers have investigated how pathogens may have constrained the expansion of dogs and donkeys, both intrusive to Africa south of the Sahara, even though their close relatives (African wolves, Canis lupus lupaster) or immediate ancestors (Nubian wild asses, Equus africanus africanus) were present within and north of the modern desert (Mitchell, 2015(Mitchell, , 2017.…”

Peter Mitchell. The donkey in human history: an archaeological perspective. 2018. Oxford: Oxford University Press; 978-0-198-74923-3 £65.

“…He then follows the limited archaeological clues of donkey presence to the west and south, tracing them briefly as far as Kenya and Tanzania. He closes the subject with his somewhat controversial argument, which has been aired in earlier published work (Mitchell 2017), that the lack of donkey expansion (but not cattle) into much of sub-Saharan Africa before recent times can largely be ascribed to barriers formed by regions infected with trypanosomiasis. There is certainly more to be written, from modern development studies and other resources, on the growing role of the working donkey in many sub-Saharan regions today, enlarging on Mitchell's suggestion that the donkey, associated as it is throughout history with the lowly and disenfranchised (notably women to this day (p. 232 and Goulder (2016: 76-79)), can provide an "entry point" (p. 3) into understanding such lives.…”

Peter Mitchell. The Donkey in Human History: An Archaeological Perspective (Oxford: Oxford University Press, 2018, 306 pp., 133 illustr., 32 in colour, 6 tables, hbk, ISBN 978-0-19-874923-3)

“…The chapter ends with the donkey's expansion to western and southern Egypt and presents direct and indirect evidence of its presence as far as Kenya and Tanzania. In Mitchell's opinion, endemic diseases could have contributed to confine its spread further south, a hypothesis regularly discussed in the author's own contribution to the literature (Mitchell, 2017).…”