Sunday, February 8, 2015

[Ornithology • 2015] Rapid Diversification and Secondary Sympatry in Australo-Pacific Kingfishers (Aves: Alcedinidae: Todiramphus)


Figure 3. Time-calibrated maximum clade credibility tree with 95% highest posterior density bars from the BEAST analysis. Node support is given as Bayesian posterior probability (PP): black circles at nodes denote PP=1.0, grey circles denote 0.95≤PP≤0.99. Unlabelled nodes denote PP<0.95. The red vertical line denotes the bGMYC species delimitation estimate (i.e. the bGMYC analysis identified as species all clades to the right of the line). Sympatric lineages are identified by colour-coded labels that correspond to their respective distributions on the map.
Note that T. sanctus is distributed across two coloured areas (green Australia and orange Solomon Islands). Actenoides hombroni, Syma and Todiramphus nigrocyaneus were removed from the base of the tree to save space.
Lettered clades (A–I) are discussed in the text and correspond to the same clades in figure 2. Illustrations of the sampled lineages from Palau (T. c. teraokai) and Vanuatu (T. c. santoensis) were not available, so representative taxa from their respective clades were used (T. c. chloris and T. c. juliae, respectively).
Illustrations courtesy of the Handbook of the Birds of the World, Lynx Edicions.   Andersen, et al. 2015 DOI: 10.1098/rsos.140375

Abstract

Todiramphus chloris is the most widely distributed of the Pacific's ‘great speciators’. Its 50 subspecies constitute a species complex that is distributed over 16 000 km from the Red Sea to Polynesia. We present, to our knowledge, the first comprehensive molecular phylogeny of this enigmatic radiation of kingfishers. Ten Pacific Todiramphus species are embedded within the T. chloris complex, rendering it paraphyletic. Among these is a radiation of five species from the remote islands of Eastern Polynesian, as well as the widespread migratory taxon, Todiramphus sanctus. Our results offer strong support that Pacific Todiramphus, including T. chloris, underwent an extensive range expansion and diversification less than 1 Ma. Multiple instances of secondary sympatry have accumulated in this group, despite its recent origin, including on Australia and oceanic islands in Palau, Vanuatu and the Solomon Islands. Significant ecomorphological and behavioural differences exist between secondarily sympatric lineages, which suggest that pre-mating isolating mechanisms were achieved rapidly during diversification. We found evidence for complex biogeographic patterns, including a novel phylogeographic break in the eastern Solomon Islands that separates a Northern Melanesian clade from Polynesian taxa. In light of our results, we discuss systematic relationships of Todiramphus and propose an updated taxonomy. This paper contributes to our understanding of avian diversification and assembly on islands, and to the systematics of a classically polytypic species complex.

KEYWORDS: island biogeography, diversification rates, divergence time estimation, great speciators, Todiramphus chloris


Michael J. Andersen, Hannah T. Shult, Alice Cibois, Jean-Claude Thibault, Christopher E. Filardi and Robert G. Moyle. 2015. Rapid Diversification and Secondary Sympatry in Australo-Pacific Kingfishers (Aves: Alcedinidae: Todiramphus).
  Ibis. DOI: 10.1098/rsos.140375  

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