The niches of nuthatches affect their lineage evolution differently across latitude.

Ecological niche evolution can promote or hinder the differentiation of taxa and determine their distribution. Niche-mediated evolution may differ among climatic regimes, and thus, species that occur across a wide latitudinal range offer a chance to test these heterogeneous evolutionary processes. In this study, we examine (a) how many lineages have evolved across the continent-wide range of the Eurasian nuthatch (Sitta europaea), (b) whether the lineages' niches are significantly divergent or conserved and (c) how their niche evolution explains their geographic distribution. Phylogenetic reconstruction and ecological niche models (ENMs) showed that the Eurasian nuthatch contained six parapatric lineages that diverged within 2 Myr and did not share identical climatic niches. However, the niche discrepancy between these distinct lineages was relatively conserved compared with the environmental differences between their ranges and thus was unlikely to drive lineage divergence. The ENMs of southern lineages tended to cross-predict with their neighbouring lineages whereas those of northern lineages generally matched with their abutting ranges. The coalescence-based analyses revealed more stable populations for the southern lineages than the northern ones during the last glaciation cycle. In contrast to the overlapping ENMs, the smaller parapatric distribution suggests that the southern lineages might have experienced competitive exclusion to prevent them from becoming sympatric. On the other hand, the northern lineages have expanded their ranges and their current abutting distribution might have resulted from lineages adapting to different climatic conditions in allopatry. This study suggests that niche evolution may affect lineage distribution in different ways across latitude.

Inferring the geographic mode of speciation by contrasting autosomal and sex-linked genetic diversity.

When geographic isolation drives speciation, concurrent termination of gene flow among genomic regions will occur immediately after the formation of the barrier between diverging populations. Alternatively, if speciation is driven by ecologically divergent selection, gene flow of selectively neutral genomic regions may go on between diverging populations until the completion of reproductive isolation. It may also lead to an unsynchronized termination of gene flow between genomic regions with different roles in the speciation process. Here, we developed a novel Approximate Bayesian Computation pipeline to infer the geographic mode of speciation by testing for a lack of postdivergence gene flow and a concurrent termination of gene flow in autosomal and sex-linked markers jointly. We applied this approach to infer the geographic mode of speciation for two allopatric highland rosefinches, the vinaceous rosefinch Carpodacus vinaceus and the Taiwan rosefinch C. formosanus from DNA polymorphisms of both autosomal and Z-linked loci. Our results suggest that the two rosefinch species diverged allopatrically approximately 0.5 Ma. Our approach allowed us further to infer that female effective population sizes are about five times larger than those of males, an estimate potentially useful when comparing the intensity of sexual selection across species.

Testing hypotheses of mitochondrial gene-tree paraphyly: unravelling mitochondrial capture of the Streak-breasted Scimitar Babbler (Pomatorhinus ruficollis) by the Taiwan Scimitar Babbler (Pomatorhinus musicus).

Species-level paraphyly inferred from mitochondrial gene trees is a prevalent phenomenon in taxonomy and systematics, but there are several potential causes that are not easily explained by currently used methods. This study aimed to test the underlying causes behind the observed paraphyly of Streak-breasted Scimitar Babbler (Pomatorhinus ruficollis) via statistical analyses of four mitochondrial (mtDNA) and nine nuclear (nuDNA) genes. Mitochondrial gene trees show paraphyly of P. ruficollis with respect to the Taiwan Scimitar Babbler (Pomatorhinus musicus), but nuclear genealogies support a sister-group relationship. Predictive coalescent simulations imply several hypothetical explanations, the most likely being mitochondrial capture of P. ruficollis by P. musicus for the observed cyto-nuclear incongruence. Further approximate Bayesian computation suggests a unidirectional introgression model with substantial level of gene flow from P. ruficollis to P. musicus during their initial divergence during the Late Pleistocene. This specific observation frames several potential causes for incongruent outcomes of mitochondrial and nuclear introgression in general, and on the whole, our results underscore the strength of multiple independent loci for species delimitation and importance of testing hypotheses that explain disparate causes of mitochondrial gene-tree paraphyly.

Molecular systematics and plumage coloration evolution of an enigmatic babbler (Pomatorhinus ruficollis) in East Asia.

The streak-breasted scimitar babbler, Pomatorhinus ruficollis, is a polytypic and taxonomically enigmatic babbler common in southern, eastern, and southeastern Asia. To infer the phylogeny of the P. ruficollis, we examined the sequences of two complete mitochondrial genes (2184 bp in total) from fourteen of the fifteen known subspecies, and an additional five nuclear genes (2657 bp in total) from ten subspecies. The mitochondrial phylogeny indicates four major clades with large geographical identity in P. ruficollis and paraphyly of the P. ruficollis species complex, with the inclusion of the olivaceus group of congeneric P. schisticeps. Together with their interbreeding in northern Indochina, we propose to lump this group into P. ruficollis. Analysis of both multilocus networks and species-tree inference recovered poor phylogenetic structure among mainland/ Hainan subspecies and exclusive groupings of the Taiwanese subspecies, consistent with the recent taxonomic revision of its species status. Our analyses also suggest strong incongruence between the morphological-based classification and molecular systematics, implying the strength of multilocus data for taxonomy.

Contaminants of legacy and emerging concern in terrestrial passerines from a nature reserve in South China: Residue levels and inter-species differences in the accumulation.

Knowledge is limited about the bioaccumulation of persistent halogenated compounds (PHCs) in terrestrial wildlife. Several PHCs, including dichlorodiphenyltrichloroethane (DDT) and its metabolites (designated as DDTs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), decabromodiphenylethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), and stable isotopes (δ(15)N and δ(13)C) were analyzed in the muscle of four terrestrial passerines, Parus major, Copsychus saularis, Pycnonotus sinensis and Pycnonotus jocosus, from a nature reserve in South China. P. major had the highest PHC concentrations, with median values of 1060, 401, 92, 25 and 0.3 ng/g lipid weight for DDTs, PCBs, PBDEs, DBDPE and BTBPE, respectively. Fractions of DDT in P. jocosus and PCBs 153, 118 and 180 in C. saularis were higher compared with the other species. The inter-species differences in PHC concentrations and profiles could be attributed to the differences in trophic level, diet, living habits and metabolic capacity among the birds.

Species-specific accumulation of halogenated flame retardants in eggs of terrestrial birds from an ecological station in the Pearl River Delta, South China.

Little information is available on the bioaccumulation of halogenated flame retardants (HFRs) in terrestrial ecosystem. Eggs of light-vented bulbul, yellow-bellied prinia, plain prinia, and dark green white-eye were collected from an ecological station in the Pearl River Delta, South China to investigate the occurrence of polybrominated diphenyl ethers (PBDEs) and several alternative HFRs, including decabromodiphenyl ethane (DBDPE), dechlorane plus (DP), hexabromobenzene (HBB), pentabromoethylbenzene (PBEB), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), pentabromotoluene (PBT), and 2,3,5,6-tetrabromo-p-xylene (pTBX). Concentrations of PBDEs, DBDPE, DP, HBB, PBEB, BTBPE, PBT, and pTBX ranged from 53-423, 6.1-609, 4.6-268, not detected (nd)-10, nd-1.4, nd-1.7, nd-7.5, and nd-3.2 ng g(-1) lw, respectively. Light-vented bulbul exhibited significantly lower levels of PBDEs, DBDPE, DP, and HBB than other three bird species due to its phytophagy and the other three bird species' insectivores. PBDEs were the predominant HFRs in bird eggs, followed by DBDPE and DP. Significant negative relationship between the fraction of anti-DP and DP concentrations was observed in bird eggs, suggesting that DP levels play an important role in determining the isomeric composition. Anti-Cl11-DP, the dechlorinated products of DP, was found in bird eggs with concentrations ranging from nd to 0.86 ng g(-1) lw and its source is worth further research.

PCBs and DDTs in light-vented bulbuls from Guangdong Province, South China: levels, geographical pattern and risk assessment.

Thirty-two light-vented bulbuls (Pycnonotus sinensis) were collected from six sampling sites in Guangdong Province, South China to investigate the geographical variation on the occurrence of polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs). Concentrations of PCBs and DDTs in the pectoral muscle of light-vented bulbul ranged from 140 to 73,000 ng/g lipid weight (lw) and 12 to 4600 ng/g lw, respectively. PCB concentrations were significantly higher in birds from e-waste site compared to other sampling sites (mean, 18,000 vs 290 ng/g lw, p<0.0001), implying that PCBs mainly came from e-waste recycling activities. No significant differences for DDT levels were observed among the sampling sites (p=0.092). Differences in PCB homologue profiles among the sampling sites were found and can be probably ascribed to different local contamination sources. p,p'-DDE (>80%) was the most abundant component of DDTs in birds. Compositional pattern of DDTs suggested that historical residue was the main source of DDT. The toxic equivalent (TEQ) concentrations had significant positive correlations with PCB concentrations, indicating that elevated PCB levels may have adverse effects on light-vented bulbuls.

Using the kingfisher (Alcedo atthis) as a bioindicator of PCBs and PBDEs in the dinghushan biosphere reserve, China.

The Dinghushan Biosphere Reserve is a nature reserve and a site for the study of tropical and subtropical forest ecosystems. Rapid industrialization and intensive electronic waste-recycling activities around the biosphere reserve have resulted in elevated levels of industrial organic contaminants in the local environment that may cause adverse effects on wildlife that inhabits this area. In the present study, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and 2 alternative brominated flame retardants (BFRs)-decabromodiphenyl ethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE)-were investigated in the biosphere reserve and a reference site by using the kingfisher (Alcedo atthis) as a bioindicator. Residue concentrations in kingfishers from the Dinghushan Biosphere Reserve ranged from 490 ng/g to 3000 ng/g, 51 ng/g to 420 ng/g, 0.44 ng/g to 90 ng/g, and 0.04 ng/g to 0.87 ng/g lipid weight for ∑PCBs, ∑PBDEs, DBDPE, and BTBPE, respectively. With the exception of the BTBPE, these levels were 2 to 5 times higher than those detected in kingfishers from the reference site. The contaminant patterns from the biosphere reserve were also different, with larger PCB contributions in comparison with the reference site. The estimated predator-prey biomagnification factors (BMFs) showed that most of the PCB and PBDE congeners and BTBPE were biomagnified in kingfishers from the biosphere reserve. The calculated toxic equivalent quantity (TEQ) concentrations of major coplanar PCB congeners in kingfishers from the biosphere reserve ranged from 18 pg/g to 66 pg/g wet weight, with some of these TEQ concentrations reaching or exceeding the levels known to impair bird reproduction and survival.

Bioaccumulation of polybrominated diphenyl ethers, decabromodiphenyl ethane, and 1,2-bis(2,4,6-tribromophenoxy) ethane flame retardants in kingfishers (Alcedo atthis) from an electronic waste-recycling site in South China.

Brominated flame retardants (BFRs) including polybrominated diphenyl ethers (PBDEs), decabromodiphenyl ethane (DBDPE), and 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), were investigated in common kingfishers (Alcedo atthis) and their prey fish from an electronic waste-recycling site in south China. Elevated BFR residues were detected in the kingfishers, with median concentrations of 8,760, 12, and 7.7 ng/g lipid weight for total PBDEs, DBDPE, and BTBPE, respectively. The calculated predator/prey biomagnification factors (BMFs) were greater than unity for most of the investigated PBDE congeners, with relatively higher values for some hexa-, hepta-, and octa-BDEs (e.g., BDEs 153, 183, 196, 197, 202, and 203). The average BMFs ranged 0.10 to 0.77 and 1.90 to 3.60 for DBDPE and BTBPE, respectively. The BMFs for BTBPE were comparable to or even greater than those for some tri- to penta-BDEs in certain predator/prey pairs, indicating potentially high environmental risks of this compound. Significantly higher concentration ratios of BDEs 202 and 207 to BDE 209 were observed in the kingfishers compared with their prey fish, and these ratios were negatively correlated with the logarithm of BDE 209 concentrations in the kingfishers. This may indicate biotransformation of BDE 209 to BDEs 202 and 207 in these birds. This is the first assessment of the biomagnification potentials of DBDPE and BTBPE in a wild piscivorous bird.

Hexabromocyclododecane in terrestrial passerine birds from e-waste, urban and rural locations in the Pearl River Delta, South China: levels, biomagnification, diastereoisomer- and enantiomer-specific accumulation.

Diastereoisomers and enantiomers of hexabromocyclododecane (HBCD) were determined in muscle and stomach contents of three terrestrial passerine birds from e-waste, urban and rural locations in South China. The highest HBCD concentration was found at the urban site, followed by the e-waste site, suggesting that HBCD was linked to urbanization and industrialization, as well as e-waste recycling activities. Trophic magnification for α-HBCD was observed in the terrestrial food chain. Diastereisomeric pattern in birds showed the predominance of α-isomer, with a minor contribution of γ-isomer. The enantiomeric analysis revealed a preferential enrichment of (-)-α-HBCD and (+)-γ-HBCD. The similarity in enantiomeric fractions of HBCD isomers between muscle and stomach contents of birds suggested that dietary uptake may be responsible for the observed nonracemic distribution of HBCD isomers in the studied birds although in vivo enantioselective biotic processes cannot be ruled out.

Brominated flame retardants in three terrestrial passerine birds from South China: geographical pattern and implication for potential sources.

Polybrominated diphenyl ethers (PBDEs), decabromodiphenyl ethane (DBDPE), polybrominated biphenyls (PBBs) and pentabromotoluene (PBT) were investigated in light-vented bulbul (LVB), long-tailed shrike (LTS) and oriental magpie-robin (OMR) collected from seven sampling sites in South China. ∑PBDEs, DBDPE, PBB 153, and PBT levels ranged from 35 to 15,000, no detected (nd)-130, nd-6800, and nd-6.8 ng/g lipid weight, respectively. Positive correlations were found between δ(15)N values and brominated flame retardant (BFR) concentrations. The BFR geographic pattern indicated that PBDEs were linked to e-waste recycling and local industry activities as well as urbanization; PBB 153 was derived from e-waste; DBDPE was mainly come from local industry activities; and no specific source was observed for PBT. PBDE congener profiles were found to be depended on bird species and sampling sites with relatively high abundances of lower brominated congeners in e-waste site and significantly higher abundance of BDE153 in LTS and OMR than in LVB.

[Preliminary discussion on the phylogenetic and taxonomic relationship of Pomatorhinus ruficollis].

The phylogenetic relationships among subspecies of Pomatorhinus ruficollis are not clear. In this paper we sequenced two mitochondrial genes (Cyt b and ND2, in total 2 184 bp) and examined twenty individuals representing ten of the eleven subspecies of P. ruficollis in China. Molecular phylogenetic trees were reconstructed using maximum parsimony, maximum likelihood and Bayesian inference methods, with P. ruficollis and P. schisticeps as in-groups, P. montanus, P. ochraceiceps, P. ferruginosus and Xiphirhynchus superciliaris as out-groups. Results indicated that P. ruficollis was paraphyletic, in which P. schisticeps was embedded, and was divided into three phylogeographic groups: southwestern China group, southeastern China group and central China group. Our results also suggested discordances between phylogenetic relationships and morphological characteristics, and clarified some intraspecific taxonomic debates.

[Composition and characteristics of understory bird communities in monsoon evergreen broadleaved forest of Mengyang, Xishuangbanna in the dry season].

Understory birds in monsoon evergreen broadleaved forest of Mengyang, Xishuangbanna, Yunnan were sampled using mist nets from October 2008 to March 2009. A total of 1423 individuals of 90 species belonging to 28 families and 7 orders were captured, among which there are 8 dominant bird species, i.e., Sliver-breasted Broadbill (Serilophus lunatus), Brown-cheeked Fulvatta (Alcippe poioicephala), White-throated Bulbul (Alophoixus pallidus), Golden-spectacled Warbler (Seicercus burkii), White-tailed Robin (Cinclidium leucurum), Black-breasted Thrush (Turdus dissimilis), Streak-Breasted Jungle Babbler (Pellorneum ruficeps), and Buff-breasted Jungle Babbler (Trichastoma tickelli). Resident birds, the major composition of the understory birds, accounted for 89.3 percent of total captures. The mean capture rate was 9.0+-3.7 individuals/(100 net-hours) and it differed significantly between months, highest in December 2008 (12.5+-1.3)individuals/(100 net-hours), lowest in February 2009 (5.2+-0.6) individuals/(100 net-hours). The most significant characteristic of understory birds in Xishuangbanna is more species abundance and lower species density compared to understory bird composition of South China. Another characteristic is that no obvious dominance pattern was observed in Babbler species. We also noticed that silver-breasted Broadbill, National Key Protection Bird, is the most abundance species in our captures, thus their habitat require further protection.