0000000000087994
AUTHOR
Urban Olsson
The Sulawesi Thrush ( Cataponera turdoides ; Aves: Passeriformes) belongs to the genus Turdus
The Asian and Australo-Papuan faunas meet and intermix across the islands of Wallacea. Untangling the origins and relationships of the species inhabiting these archipelagos is an ongoing project that has lasted for well over a century. In recent years, molecular phylogenetic studies have made considerable progress in clarifying the affinities of enigmatic Wallacean taxa, but taxonomic riddles remain, even in groups as well studied as birds. Such is the case with Sulawesi Thrush Cataponera turdoides, a scarce and elusive montane songbird whose taxonomic placement has remained controversial since its description. To determine the evolutionary relationships of this monotypic genus, we obtained…
Niche filling slows the diversification of Himalayan songbirds.
In Himalayan songbirds, the speciation rate is ultimately set by ecological competition, rather than by the rate of acquisition of reproductive isolation. The beginnings of adaptive radiation and speciation have been widely studied — in Darwin's finches, sticklebacks and cichlid fish, for example — but relatively little is known about what happens next. Specifically, what is the rate-limiting step for the establishment of new species? This seven-year study of the 358 songbird species found on the Himalayan slopes suggests that it is the rates at which new niches are created and occupied that limits diversification, not the rate at which new species form through reproductive isolation. Speci…