How do seemingly non-vagile clades accomplish trans-marine dispersal? Trait and dispersal evolution in the landfowl (Aves: Galliformes)

• Published in: Proceedings of the Royal Society. B, Biological sciences Vol. 284; no. 1854; p. 20170210
• Main Authors: Hosner, Peter A., Tobias, Joseph A., Braun, Edward L., Kimball, Rebecca T.
• Format: Journal Article
• Language: English
• Published: England The Royal Society 17-05-2017; The Royal Society Publishing
• Edition: Royal Society (Great Britain)
• Subjects: Alpine environments; Animal Distribution; Animals; Anurophasis; Biological Evolution; Birds; Body size; Colonization; Community composition; Coturnix; Dispersal; Dispersal Limitation; Dispersion; Evolution; Galliformes; Galliformes - classification; High aspect ratio; Island Gigantism; Islands; Madagascar; Margaroperdix; New Guinea; Oceanic islands; Phylogeny; Slender wings; Species extinction; Taxa; Terrestrial environments; Turkeys; Ultraconserved Elements; New Guinea; Madagascar; phylogeny; island gigantism; dispersal limitation; Galliformes; ultraconserved elements
• ISSN: 0962-8452; 1471-2954
• DOI: 10.1098/rspb.2017.0210

Dispersal ability is a key factor in determining insular distributions and island community composition, yet non-vagile terrestrial organisms widely occur on oceanic islands. The landfowl (pheasants, partridges, grouse, turkeys, quails and relatives) are generally poor dispersers, but the Old World quail (Coturnix) are a notable exception. These birds evolved small body sizes and high-aspect-ratio wing shapes, and hence are capable of trans-continental migrations and trans-oceanic colonization. Two monotypic partridge genera, Margaroperdix of Madagascar and Anurophasis of alpine New Guinea, may represent additional examples of trans-marine dispersal in landfowl, but their body size and wing shape are typical of poorly dispersive continental species. Here, we estimate historical relationships of quail and their relatives using phylogenomics, and infer body size and wing shape evolution in relation to trans-marine dispersal events. Our results show that Margaroperdix and Anurophasis are nested within the Coturnix quail, and are each ‘island giants’ that independently evolved from dispersive, Coturnix-like ancestral populations that colonized and were subsequently isolated on Madagascar and New Guinea. This evolutionary cycle of gain and loss of dispersal ability, coupled with extinction of dispersive taxa, can result in the false appearance that non-vagile taxa somehow underwent rare oceanic dispersal.