Africa produces edible termites at rates unrivalled in the land of marsupials because the African insects are grazers rather than wood-eaters.
Prof. Mumblebard claims: The numbat and the aardwolf both rely on termites, and are convergent in terms of their peg-like teeth and long tongues. They remain different in body size and other features simply because they’re as unrelated as it’s possible for mammals to be: one is marsupial and the other placental.
Robin and the Honey Badger respond: The difference in size between numbat and aardwolf reveals major ecological differences relating to woodiness and nutrient availability between the Australian and southern African habitats. The numbat eats wood-eating termites, whereas the aardwolf eats dwarf shrub- and grass-eating termites. Although the southern interiors of Australia and South Africa have similar dry climates, the nutrient-poverty of the former has resulted in a wooded landscape while the nutrient-richness of the latter has resulted in a landscape dominated by dwarf shrubs and grasses. Trees are intrinsically less productive than small plants in terms of food – directly or via termites. So a species relying on termites in a nutrient-poor wooded habitat is likely to be smaller than a species relying on termites in a nutrient-richer low vegetation. Numbat and aardwolf are typical of many other organisms from insects to elephant that differ intercontinentally in parallel ways.
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Featured image: The numbat (Myrmecobius fasciatus) by Helenabella (CC BY-SA 3.0, Numbat)