Evolution, Distribution and Stage of Speciation in the Rhipidura fuliginosa complex in Australia

Abstract

In Australia, the Rhipidura fuliginosa complex consists of four quite distinct groups of populations: phasiana in mangroves along north-western Australian coasts; albicauda in mulga deserts of central and inland-western Australia; keasti in highland rainforest in north-eastern and mid-eastern Queensland; and preissi, alisteri and albiscapa in south-western Australia, south-eastern Australian and Tasmania. Differences in their songs, habitat, breeding seasons, clutch size and mobility as well as in their morphology indicate that some may have diverged to species level. The mangrove form, the most divergent, probably originated under an arid climatic regime and spread to, rather than from, New Guinea. The desert form is a partial nomad and an opportunistic breeder, like many other inland birds, and was clearly derived from the southern component. The form keasti, previously known as frerei, has a disjunct distribution, is sedentary and represents a morphological link with the melanistic R. albolimbata of highland rainforests of New Guinea. All subspecies of the southern group are partly migratory but apparently only alisteri winters in far-northern Australia.