Phylogeographical history of the Olive Woodpecker Dendropicos griseocephalus, a species widely distributed across Africa

Abstract

Few studies have quantified the extent of genetic differentiation within widely distributed polytypic African bird species with disjunct ranges. Current knowledge indicates that high levels of genetic differentiation are found for such lineages but generalization of the pattern requires further comparisons with other co‐distributed taxa. We assessed the extent of phylogeographical structure across the range of the Olive Woodpecker Dendropicos griseocephalus using mitochondrial and nuclear intron data. The Olive Woodpecker occupies the forests of Central (Dendropicos griseocephalus ruwenzori) and Eastern (Dendropicos g. kilimensis) Africa, with a disjunct morphological lineage (Dendropicos g. griseocephalus) occurring in southern Africa. Each of the subspecies lineages can be diagnosed using morphology. Phylogenetic analyses of our sequence data recovered three monophyletic lineages with kilimensis sister to ruwenzori, and griseocephalus as sister to the clade uniting these two taxa. Molecular species delimitation methods and estimates of gene flow under the isolation‐with‐migration model suggest that the clade uniting the central and eastern subspecies may be recognized as distinct at the species level from the nominate subspecies, which is restricted to southern Africa. We conclude that D. griseocephalus (Boddaert, 1783) and D. ruwenzori (Sharpe, 1902) (including subspecies kilimensis) should be considered full species. The biogeographical pattern we uncover for the Olive Woodpecker differs from that of other co‐distributed widespread species both in terms of the order of sequence divergence of lineages occupying different areas of endemism in Africa, and in the timing of divergence, being younger (0.5–0.7 mya BP) than that recovered for the co‐distributed Square‐tailed Drongo Dicrurus ludwigii (0.9–1.6 mya BP).

Biogeographical Importance of the Livingstone Mountains in Southern Tanzania: Comparative Genetic Structure of Small Non-volant Mammals

“…The Makambako Gap is an unforested, dry, low-lying region covered by miombo woodland separating the LM (i.e., the SRM) and the EAM (Figure 1B). It has been shown to be an important barrier for a range of taxa, such as Tornier's cat snake (Gravlund, 2002), some bush vipers (Menegon et al, 2014), double-bearded chameleons (Ceccarelli et al, 2014), mountain greenbuls (Roy et al, 1998, reviewed in Kahindo et al, 2007Fjeldså and Bowie, 2008), olive woodpeckers (Fuchs et al, 2021), and Tanzanian vlei rats (Taylor et al, 2009), but not for others, e.g., Uzungwe Mountain Bush Vipers (Menegon et al, 2014), forest batis (Fjeldså et al, 2006, reviewed in Kahindo et al, 2007Fjeldså and Bowie, 2008), green barbets (Fjeldså and Bowie, 2008;Fjeldså et al, 2010) and Kihaule's mouse shrews (Stanley and Esselstyn, 2010). Similar conclusions can be drawn from our review of small mammals.…”