A review of evolutionary research on birds of the New Guinean savannas and closely associated habitats of riparian rainforests, mangroves and grasslands

ABSTRACT

Three isolated areas of non-rainforested open woodland habitats, often collectively termed ‘savanna’, occur in eastern New Guinea and are here termed the Trans-Fly, Central Province and Oro Province savannas. Their avifauna is mostly shared with eucalypt-dominated savannas widespread across tropical and subtropical Australia. Though the avifaunas of these New Guinean savanna regions are well-inventoried, their potential for evolutionary and ecological research has been relatively little explored. We outline the distribution and palaeoenvironmental history of these New Guinean savannas. We describe the often underappreciated floristic uniqueness and complexity of the largest bloc, which is the Trans-Fly. We discuss avian endemism and species diversity in the New Guinean savannas and we review divergence of the New Guinean populations of savanna birds from their closest relatives, usually in Australia. We review molecular phylogeographic patterns evident in New Guinea savanna birds. Several species are closest to populations or other species in north-western Australia not the geographically closer north-eastern Australia. We discuss palaeo-modelling of Pleistocene habitats that explains this. We review bird migration between Australia and the Trans-Fly. Throughout, we highlight areas for further research such as the origin of the Oro Province savannas and the origins of several distribution patterns that seem particularly puzzling.

KEYWORDS:

• New Guinea
• savanna
• birds
• Trans-Fly
• phylogeography

Acknowledgements

Our work in the New Guinean savannas would not have been possible without all authorities, including governmental and community groups, landholders and land managers, who have either granted permits to collect or facilitated the field work to collect specimens. For enabling our field work, we are grateful to: Barnabas Wilmott of the Papua New Guinea Conservation and Environment Protection Authority; staff at the National Research Institute, Port Moresby PNG for assistance before and during all field work; Tonda Wildlife Management Committee (Siwai Nema, Sembara, Yaska Kobi) for generously allowing us to undertake our research in the Bensbach region, Bob Bates (Trans Niugini Tours), Hinterland Airlines, Kapai Assi (Bensbach Lodge), and Garry Barmby (Director of Angling Adventures) for assistance with travel and lodging there; Biatus Bito and Miriam Supuma for invaluable assistance and local knowledge; Port Moresby staff of TNT; Mark Nizette (Kokoda Initiative, Department of Environment and Energy, Australia), and Jack Dumbacher (California Academy of Sciences, San Francisco, California). The former Director, Andrew Moutu, and staff at the Papua New Guinea National Museum and Art Gallery between 2012 and 2016 helped enormously. We are especially grateful for to the communities at Agevairu, Bensbach, Popondetta and Rigo for their generous help and support of our field work, which simply would have been impossible without them. We thank authors who have allowed us to cite work in review and we acknowledge a great debt to Bruce Beehler and Thane Pratt for their work in documenting the entire New Guinean avifauna. For their generous assistance in deriving estimates of New Guinean savanna areas we thank Susan Cuddy, Bryant Allen, Tim McVicar, Brett Abbott and Jenny Bellamy.

Supplementary material

Supplemental data for this article can be accessed here.