Disparate origins for endemic bird taxa from the ‘Gondwana Rainforests’ of Central Eastern Australia

Kieren J Mitchell,Holly Heiniger,Paul M Oliver,Leo Joseph,Andrew F Hugall

doi:10.1093/biolinnean/blab031

Abstract

Abstract Subtropical and temperate rainforests of Central Eastern Australia are some of the largest remaining fragments of their kind globally. The biota of these rainforests appears to comprise two broad biogeographical elements: a more ancient (Miocene or older) and typically upland temperate (‘Gondwanan’) element and a younger (Plio-Pleistocene) lowland tropical element. We present the first phylogenetic synthesis of the spatiotemporal origins for the eight bird taxa endemic to Central Eastern Australian Rainforests. At least five of these eight focal taxa show Plio-Pleistocene divergences from their respective northern sister taxa, consistent with origins driven by recent expansion and contraction of lowland rainforest. In contrast, two more strictly upland species, the rufous scrub-bird (Atrichornis rufescens) and the logrunner (Orthonyx temminckii), diverged from their nearest living relatives during the Miocene, suggesting potentially longer histories of persistence and more temperate origins. Finally, we did not recover reciprocal monophyly in mitogenomes from the two extant lyrebirds, Albert’s lyrebird (Menura alberti) and the superb lyrebird (Menura novaehollandiae). The disparate divergence ages recovered among all eight taxa are consistent with the biota of the Central Eastern Australian Rainforests comprising isolates either of younger age and tropical lowland origins or of older age and temperate upland origins.

Highlights

Since the Miocene climatic optimum, rainforests in Australia have contracted and fragmented (Bryant & Krosch, 2016), and Plio-Pleistocene glacial cycles have driven further expansion and retraction of rainforest habitats (e.g. Hugall et al, 2002)
Samples of Podargus ocellatus from across New Guinea and eastern Australia were reciprocally monophyletic with respect to other Podargus species [bootstrap support (BS) = 100%; Fig. 2A; Supporting Information, Fig. S1]
Within Podargus ocellatus, the sample from New Guinea was sister to the remaining samples (BS = 100%), which in turn comprised two reciprocally monophyletic clades corresponding to the plumed frogmouth (Podargus [o.] plumiferus) from the Central Eastern Australian Rainforests (CEAR) and Podargus o. marmoratus from Cape York Peninsula

Summary

Introduction

Since the Miocene climatic optimum, rainforests in Australia have contracted and fragmented (Bryant & Krosch, 2016), and Plio-Pleistocene glacial cycles have driven further expansion and retraction of rainforest habitats (e.g. Hugall et al, 2002). The rainforests of Australia are concentrated in < 1% of the land area of the continent, mainly along its eastern seaboard. Fewer studies have focused on the subtropical Central Eastern Australian Rainforests (CEAR) in south-eastern Queensland and north-eastern New South Wales (Hugall et al, 2003). These borderlands are home to some of the largest remaining areas of subtropical and temperate rainforest in the world, and they too host a distinct assemblage of endemic species (Weber et al, 2014)

Methods

Results

Discussion

Conclusion