Comparative Phyloclimatic Analysis and Evolution of Ecological Niches in the Scimitar Babblers (Aves: Timaliidae: Pomatorhinus)

Abstract

We present the first extensive and integrative analysis of niche evolution based on climatic variables and a dated molecular phylogeny of a heterogeneous avian group of Southeast Asian scimitar babblers of the genus Pomatorhinus. The four main clades of scimitar babblers have species that co-occur in similar areas across southern Asia but some have diverged at different timeframes, with the most recently evolved clade harboring the highest number of species. Ecological niche models and analysis of contributing variables within a phylogenetic framework indicate instances of convergent evolution of members of different clades onto similar ecological parameter space, as well as divergent evolution of members from within clades. Pomatorhinus species from different clades occupying Himalayan foothills show convergence towards similar climatic tolerances, whereas within a clade, allopatric sister-species occurring in the Himalayas have diverged to occupy different climatic parameter spaces. Comparisons of climatic tolerances of Himalayan foothills taxa with species distributed further south in Assam/Burma and Burma/Thailand indicate convergence towards similar parameter spaces in several climatic variables. Niche overlap was observed to be lower among species of the youngest clade (ruficollis) and higher among species of older clades (ferruginosus). Analysis of accumulation of ecological disparity through time indicates rapid divergence within recent time frames. As a result, Himalayan taxa originating at different temporal scales within the four main scimitar babbler clades have differentiated ecologically only in recently diverged taxa. Our study suggests that the repeated orogenic and climatic fluctuations of the Pliocene and Pleistocene within mainland Southeast Asia served as an important ecological speciation driver within scimitar babblers, by providing opportunities for rapid geographic expansion and filling of novel environmental niches.

Avian SDMs: current state, challenges, and opportunities

“…For instance, Nyári and Reddy (2013) revealed patterns of niche filling and convergent evolution among different lineages of the babbler genus Pomatorhinus for different climatic variables. Furthermore, apart from some interesting exceptions, niches in manakins (Pipridae) are conservative in terms of ecological landscape and climate (Anciães and Peterson 2009).…”

Genetic confirmation of the species status of Jabouilleia naungmungensis

“…This difference in taxonomic treatment was subsequently debated in the literature and in online forums (Alström et al 2013;Collar 2011;Collar and Pilgrim 2007;Eames and Mahood 2011;Moyle et al 2012;Nyári and Reddy 2013;Oliveros et al 2012;Rappole et al 2005Rappole et al , 2008Reddy 2008;Reddy and Moyle 2011;Renner et al 2015). At present, taxonomic authorities appear to be following the arguments presented by Collar (2011) in treating J. naungmungensis as a subspecies of J. danjoui (Dickinson and Christidis 2014) or Napothera danjoui (Clements et al 2015) (for differences between the two generic classifications, refer to Fig.…”

Climatic niche evolution in the viviparous Sceloporus torquatus group (Squamata: Phrynosomatidae).

“…Orogenic and glacial periods probably promote cycles of the availability of new territories and isolation, which could promote the rapid accumulation of ecological differences between the species of the group. (Sexton et al 2009;Nyári & Reddy, 2013). We refer to the niche or ecological niche of the 6 species to be those biotic and abiotic variables that allow the persistence of populations 7 (Hutchinson, 1957).…”