The phylogenetics and evolution of Africa's larks (Alaudidae)

Abstract

The larks are a group of dull coloured birds that are conservative in plumage coloration and pattern due to the requirements for camouflage in open habitats. Because many species inhabit structurally similar habitats the group is also characterised by a great deal of morphological convergence. Variation in plumage and morphology is frequently as great within species as it is between species, leading to many inconsistent and controversial taxonomic treatments and classifications at an intra- and inter-generic level, and when defining specific and sub-specific boundaries. The advent of genetic techniques and success at applying these to species complexes in southern Africa suggested that a molecular phylogeny of the family would elucidate relationships that could not be determined via traditional taxonomic practices. In this study 2009 nucleotides of two mitochondrial DNA genes, cytochrome b and 16S rRNA (Chapter 2), and 2872 nucleotides of the nuclear exon RAG-l (Chapter 3) were used to generate a robust phylogeny of the family Alaudidae. The former analysis included 55 species and the latter 25. These data were also combined to construct a combined evidence phylogeny (Chapter 7). Within the family, several genera recognised by more traditional taxonomies are polyphyletic, including Ammomanes, Eremalauda .and Certhilauda. Two other genera, Calandrella and Mirafra, are best treated as multiple genera (Chapter 2). The sampled Alaudidae can be divided into three main radiations, the ammomanid larks, mirafrid larks and alaudid larks (Chapter 3). Within the ammomanid larks, there is strong support for: (1) a southern African' radiation comprising Chersomanes, the Long-billed Lark complex (Certhilauda) and Ammomanes (Ammomanopsis) grayi ,with Alaemon allied to this radiation; and (2) a .Saharo-Sindian radiation comprising Ramphocoris c1otbey, Ammomanes cinc(urus, and A. deserti sister to the Afro-Sindian sparrowlark Eremopterix clade. The Madagascan endemic Mirafra hova was a surprise basal member of Eremopterix.