Biogeographic models of gene flow in two waterfowl of the Australo‐Papuan tropics

Abstract

There are many large, easy-to-observe anseriform birds (ducks, geese, and swans) in northern Australia and New Guinea and they often gather in large numbers. Yet, the structure of their populations and their regional movements are poorly understood. Lack of understanding of population structure limits our capacity to understand source-sink dynamics relevant to their conservation or assess risks associated with avian-borne pathogens, in particular, avian influenza for which waterfowl are the main reservoir species. We set out to assess present-day genetic connectivity between populations of two widely distributed waterfowl in the Australo-Papuan tropics, magpie goose Anseranas semipalmata (Latham, 1798) and wandering whistling-duck Dendrocygna arcuata (Horsfield, 1824). Microsatellite data were obtained from 237 magpie geese and 64 wandering whistling-duck. Samples were collected across northern Australia, and at one site each in New Guinea and Timor Leste. In the wandering whistling-duck, genetic diversity was significantly apportioned by region and sampling location. For this species, the best model of population structure was New Guinea as the source population for all other populations. One remarkable result for this species was genetic separation of two flocks sampled contemporaneously on Cape York Peninsula only a few kilometers apart. In contrast, evidence for population structure was much weaker in the magpie goose, and Cape York as the source population provided the best fit to the observed structure. The fine scale genetic structure observed in wandering whistling-duck and magpie goose is consistent with earlier suggestions that the west-coast of Cape York Peninsula is a flyway for Australo-Papuan anseriforms between Australia and New Guinea across Torres Strait.

Avian influenza in Australia: a summary of 5 years of wild bird surveillance

“…Our data show a low frequency of AIVs in these birds soon after their arrival . However, recent wild bird population genetic studies show New Guinea to be the source of Anseriformes populations in northern Australia and the recent introduction and establishment of an H10 AIV reassortant virus with a North American HA gene emphasises the need to remain vigilant to the further incursion of exotic AIVs into Australia.…”

Detection and characterisation of coronaviruses in migratory and non-migratory Australian wild birds

“…Regular spill-over of coronaviruses from Charadriiformes to Anseriformes could explain why many Australian duck gammacoronaviruses were similar to the duck gammacoronaviruses from Asia and more distant regions. Australian duck species rarely come into direct contact with Palearctic waterfowl 28 . Some degree of geographical gammacoronavirus lineage formation might therefore have been expected, if this was the only means of transmission of duck gamma-CoV's, due to the high rate of mutation and recombination observed in other avian gamma-CoV's 29,30 .…”

Multilocus phylogeography of Australian teals (Anas spp.): a case study of the relationship between vagility and genetic structure

“…In contrast, the mainly, or solely, short‐distance movements of the more sedentary chestnut teal make it likely that eastern and western populations remain segregated. The results presented here suggest that differences in vagility and movement ecology have a prominent effect on inter‐population differentiation (see also Miller et al 2011, Roshier et al 2012) and highlights the likely importance of non‐breeding movements on inter‐connectivity among widely dispersed populations.…”