Expansion from lowland Pleistocene refugia followed by cryptic introgression in an African elevational generalist bird
This study aimed to determine if a species found in a wide range of forested habitats across tropical Africa matched patterns of expansion from Pleistocene refugia similar to lowland or highland taxa. We found three strongly divergent genetic groups, with signs of mitochondrial introgression across an unknown contact zone in the Congo Basin. Notably, we found stronger population structure and lower diversity in the more restricted montane populations, consistent with the habitat not being widespread during glacial periods.