Larks (Alaudidae) as indicative of ecological differences between nutrient-poor heathlands in Australia vs South Africa

In previous Posts, I have pointed out that fynbos (South Africa), although ostensibly the ecological counterpart of kwongan (Australia), is considerably more fertile.

One of the problems with intercontinental comparisons of this kind is that the biotas are so different that it is hard to disentangle phylogenetic constraints from ecological adaptations.

For example, the marsupial Notamacropus irma (https://www.inaturalist.org/taxa/1453435-Notamacropus-irma) metabolises, grows, and reproduces more slowly than its ostensible counterpart, the bambi Raphicerus melanotis (https://www.inaturalist.org/taxa/42376-Raphicerus-melanotis). Is this really because kwongan is nutrient-poorer, and more prone to wildfire, than fynbos, or is it merely because two fundamentally different clades of mammals are represented?

There are, however, a few genera of plants and animals are shared between these two continents, and these provide an opportunity for relatively straightforward comparison.

In the case of birds, the shared genera are mainly raptors and owls. This limits their relevance, because their position at the top of food-pyramids means that they have little interaction with soils and plants.

This reduces the relevant genera to Turnix (Turnicidae), Coturnix (Phasianidae), Zosterops (Zosteropidae), and Mirafra (Alaudidae).

https://www.inaturalist.org/taxa/7318-Mirafra-javanica

https://www.inaturalist.org/taxa/204543-Mirafra-apiata

Posted on May 30, 2023 01:44 AM by milewski