Contrasting phylogeographic signatures in two Australo‐Papuan bowerbird species complexes (Aves: Ailuroedus)

Abstract

The Australo‐Papuan catbird genus Ailuroedus has a complex distribution and a contested taxonomy. Here, we integrate phylogenetic analysis of DNA data and morphology to study the group's biogeography and to re‐examine its taxonomy. We couple phylogeographic and abiotic data to examine differences between the major groups defined in our phylogenetic analysis. Our results are consistent with Ailuroedus catbirds being divided into two species complexes, one distributed in humid forests in the lowlands on New Guinea and another in comparably drier and colder forests mainly in mid‐mountains on New Guinea and Australia. Vicariant events during the Pliocene are surmised to have been the major force in shaping the contemporary phylogeographical signature of this genus. Several previously suggested vicariant events, such as fragmentation of xeric forests in Australia and the uplift of the central mountain range on New Guinea, are reinforced as important Pliocene barriers for tropical forest taxa in this region. Interaction between Pleistocene climatic fluctuations and differences in habitat requirements may explain a higher and more recent population structures in the mid‐mountain catbird complex and the lack of representatives from the lowland clade in the comparably drier Australia. Phylogeographical patterns in both catbird complexes, respectively, both comply and deviate from other lowland and mid‐mountain taxa in the region. This highlights that taxon‐specific properties, such as their historical spatial and ecological distributions, capacity to disperse and tolerance to habitat changes, affect the phylogeographical histories of organisms. Within both species complexes, the genetic differentiation between several geographically isolated populations was found to exceed those commonly observed for avian sister species. As these genetically distinct taxa also were found to be morphological diagnosable, we suggest a revised classification of the genus Ailuroedus, where we recognize three species within the lowland complex and seven species within the mid‐mountain complex.

Mountain colonisation, miniaturisation and ecological evolution in a radiation of direct-developing New Guinea Frogs (Choerophryne, Microhylidae)

“…Recent work on beetles, mammals and birds has suggested a similar association between diversification and the recent uplift of mountains in New Guinea (Meredith et al, 2010; Toussaint et al, 2014; Irestedt et al, 2015). In this study we complement such work by providing the first molecular phylogeny of a vertebrate clade (Clade A within Choerophryne ) that is both moderately diverse (15 nominal taxa), and almost entirely endemic to the New Guinea Highlands (>1,000 m a.s.l.).…”

“…Despite the biological wealth and high endemism of the New Guinea Mountains (Tallowin et al, 2017) and emerging evidence for major evolutionary radiations (Toussaint et al, 2014; Givnish et al, 2015), only a small number of phylogenetic studies of lineages with distributions centred on the montane regions of New Guinea have been published (Meredith et al, 2010; Toussaint et al, 2013; Irestedt et al, 2015). Our study complements the recent work focusing on volant or large-bodied taxa, by presenting data for a lineage of small, direct-developing frogs that may be presumed to have comparatively low vagility.…”

“…In New Guinea there is already compelling evidence that the uplift of the Central Cordillera has isolated northern and southern vicars in lowland and aquatic taxa (Rawlings & Donnellan, 2003; Georges et al, 2014), and potentially also lower montane taxa (Irestedt et al, 2015). However, our sampling of Choerophryne did not reveal extensive north-south vicariance, although one possible exception is a recently described pair of potential sister taxa in Clade B from hill and lower montane forest; C. gracilirostris (south) and C. grylloides (north) that are estimated to have diverged around 10 mya.…”

Rapid expansion and diversification into new niche space by fluvicoline flycatchers

“…For laboratory procedures from fresh tissue samples see Irestedt et al (2002), Fjeldså et al (2003), Ohlson et al (2008) and Kimball et al (2009). For degraded DNA from foot pad samples we followed the recommendations in Irestedt et al (2016). All new primers for amplifying short overlapping DNA fragment for those degraded samples are listed in Supplementary material Appendix 1 Table A2.…”

The phylogenetic position of the world's smallest passerine, the Pygmy Bushtit Psaltria exilis

“…As the DNA obtained from old museum study skins is generally heavily degraded, the laboratory work was conducted under strict conditions to avoid contamination, following the procedures described in Irestedt et al . (, in press). We specifically designed primers that PCR‐amplified the individual loci in short c .…”