Multilocus phylogeography, population genetics and niche evolution of Australian Brown and Black-tailed Treecreepers (Aves: Climacteris)

The Carpentarian barrier across northeastern Australia is a major biogeographic barrier and a generator of biodiversity within the Australian Monsoonal Tropics. Here we present a continent-wide analysis of mitochondrial (control region) and autosomal (14 anonymous loci) sequence and indel variation and niche modeling of Brown and Black-tailed Treecreepers (Climacteris picumnus and C. melanurus), a clade with a classic distribution on either side of the Carpentarian barrier. mtDNA control region sequences exhibited reciprocal monophyly and strong differentiation (Fst = 0.91), and reveals a signature of a recent selective sweep in C. picumnus. No loci among 14 anonymous autosomal markers exhibited reciprocal monophyly between species, and a variety of tests support an isolation-with-migration model of divergence, albeit with low levels of gene flow across the Carpentarian barrier and a divergence time between species of ~1.7 – 2.8 MYA, depending on the model and assumptions about generati...