Co-phylogeny of a hyper-symbiotic system: Endosymbiotic bacteria (Gammaproteobacteria), chewing lice (Insecta: Phthiraptera) and birds (Passeriformes).

Chewing lice are hosts to endosymbiotic bacteria as well as themselves being permanent parasites. This offers a unique opportunity to examine the cophylogenetic relationships between three ecologically interconnected organismal groups: birds, chewing lice, and bacteria. Here, we examine the cophylogenetic relationships between lice in the genus Guimaraesiella Eichler, 1949, their endosymbiotic Sodalis-allied bacteria, and a range of bird species from across South China. Both event and distance-based cophylogenetic analyses were explored to compare phylogenies of the three organismal groups. Pair-wise comparisons between lice-endosymbionts and bird-endosymbionts indicated that their evolutionary histories are not independent. However, comparisons between lice and birds, showed mixed results; the distance-based method of ParaFit indicated that their evolutionary histories are not independent, while the event-based method of Jane indicated that their phylogenies were no more congruent than expected by chance. Notably, louse host-switching does not seem to have affected bacterial strains, as conspecific lice sampled from distantly related hosts share bacteria belonging to the same clade.

Mixed-species bird flocks re-assemble interspecific associations across an elevational gradient.

Understanding how non-trophic social systems respond to environmental gradients is still a challenge in animal ecology, particularly in comparing changes in species composition to changes in interspecific interactions. Here, we combined long-term monitoring of mixed-species bird flocks, data on participating species' evolutionary history and traits, to test how elevation affected community assemblages and interspecific interactions in flock social networks. Elevation primarily affected flocks through reassembling interspecific associations rather than modifying community assemblages. Specifically, flock networks at higher elevations (compared to low elevations) had stronger interspecific associations (larger average weighted degree), network connectivity (enhanced network density) and fewer subnetworks. A phylogenetic and functional perspective revealed that associations between similar species weakened, whereas connections between dissimilar and/or random species were unchanged or strengthened with elevation. Likewise, network assortativity for the traits of vertical stratum and breeding period declined with elevation. The overall pattern is a change from modular networks in the lowlands, where species join flocks with other species that have matching traits, to a more open, random system at high elevations. Collectively, this rewiring of interspecific networks across elevational gradients imparts network stability and resiliency and makes mixed-species flocks less sensitive to local extinctions caused by harsh environments.

Long-term trends in the phylogenetic and functional diversity of Anatidae in South China coastal wetlands.

Species loss has attracted much attention among scientists for more than half a century. However, we have little information on the trends in phylogenetic and functional changes behind the species loss although this information is always asynchronous and important for conservation and management. We measured community trends in Anatidae (ducks and geese) for the last 50 yr to quantify trends in phylogenetic and functional diversity patterns coinciding with taxonomic historical dynamics. We used one-way ANOVAs to test if there was a significant historical trend in communities of Anatidae. We characterized taxonomic, phylogenetic, and functional diversity of communities. For taxonomic diversity, we used species richness (SR). For phylogenetic diversity, we calculated the standardized effect size of mean pairwise distances (ses.MPD) and the standard effect size of mean nearest taxon distances (ses.MNTD) in communities. For functional diversity, we calculated functional richness (FRic), functional evenness (FEve), functional divergence (FDiv), and the community-level weighted means (CWM) of trait values for diet, foraging stratum, and body mass, separately. From the 1950s to 2010s, species richness declined without significant trends. The ses.MNTD of Anatidae communities showed no clear trends. However, ses.MPD of Anatidae communities declined dramatically during this period. For functional diversity, functional evenness of diet, foraging stratum, body mass, and functional dispersion of diet, foraging stratum did not increase or decline significantly. However, functional evenness of all traits, functional richness, and functional dispersion of body mass showed declined trends. The basic phylogenetic diversity and species body mass of Anatidae communities declined significantly because of a declining trend in the relative independent branch of geese. This makes it more challenging for implement community recovery in the future. More attention in conservation biology should consider taxonomic diversity and asynchrony in phylogenetic and functional diversity.

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.

Effectiveness of protected areas for vertebrates based on taxonomic and phylogenetic diversity.

Establishing protected areas is the primary goal and tool for preventing irreversible biodiversity loss. However, the effectiveness of protected areas that target specific species has been questioned for some time because targeting key species for conservation may impair the integral regional pool of species diversity and phylogenetic and functional diversity are seldom considered. We assessed the efficacy of protected areas in China for the conservation of phylogenetic diversity based on the ranges and phylogenies of 2279 terrestrial vertebrates. Phylogenetic and taxonomic diversity were strongly and positively correlated, and only 12.1-43.8% of priority conservation areas are currently protected. However, the patterns and coverage of phylogenetic diversity were affected when weighted by species richness. These results indicated that in China, protected areas targeting high species richness protected phylogenetic diversity well overall but failed to do so in some regions with more unique or threatened communities (e.g., coastal areas of eastern China, where severely threatened avian communities were less protected). Our results suggest that the current distribution of protected areas could be improved, although most protected areas protect both taxonomic and phylogenetic diversity.

Seven new species of Resartor Gustafsson et Bush, 2017 (Phthiraptera: Ischnocera: Philopteridae) from Asian 'babblers' (Passeriformes: Leiothrichidae, Paradoxornithidae).

Seven new species of chewing lice in the genus Resartor Gustafsson et Bush, 2017 are described and illustrated. They are: Resartor albofulvus sp. n. ex Heterophasia desgodinsi desgodinsi (Oustalet); Resartor apimimus sp. n. ex Heterophasia picaoides wrayi (Ogilvie-Grant); Resartor aterrimus sp. n. ex Minla ignotincta mariae La Touche; Resartor extraneus sp. n. ex Lioparus chrysotis swinhoii (Verreaux); Resartor guangxiensis sp. n. ex Trochalopteron milnei sinianum Stresemann; Resartor longisuturalis sp. n. ex Actinodura cyanouroptera wingatei (Ogilvie-Grant); Resartor seminudus sp. n. ex Leiothrix argentauris tahanensis (Yen). All species differ in the shape of the head, shape of the male genitalia and abdominal chaetotaxy. A checklist and a key to the species of Resartor are provided.

Characterization on the phase separation behavior of styrene-butadiene rubber/polyisoprene/organoclay ternary blends under oscillatory shear.

The present work investigated the influence of organoclay (organo-montmorillonite, OMMT) on the phase separation behavior and morphology evolution of solution polymerized styrene-butadiene rubber (SSBR)/low vinyl content polyisoprene (LPI) blends with rheological methodology. It was found that the incorporation of OMMT not only reduced the droplet size of the dispersion phase, slowed down the phase separation kinetics, also enlarged the processing miscibility window of the blends. The determination on the wetting parameters indicated that due to the oscillatory shear effect, the OMMT sheets might localize at the interface between the two phases and act as compatibilizer or rigid barrier to prevent domain coarsening, resulting in slow phase separation kinetics, small droplet size, and stable morphology. The analysis of rheological data by the Palierne model provided further confirmation that the addition of OMMT can decrease the interfacial tension and restrict the relaxation of melt droplets. Therefore, a vivid "sea-fish-net" model was proposed to describe the effect of OMMT on the phase separation behavior of SSBR/LPI blends, in which the OMMT sheets acted as the barrier (net) to slow down the domain coarsening/coalescence in phase separation process of SSBR/LPI blends.

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.

Patterns and processes underlying understory songbird communities in southern China.

Understory bird communities, especially those comprising insectivores, are highly sensitive to forest loss and fragmentation. Currently, there is little knowledge regarding the large-scale diversity patterns of understory bird communities, particularly in Eastern Asia. Consequently, we aimed to identify the distribution patterns of understory birds in southern China and the factors underlying these patterns. We analysed the diversity distribution patterns of taxonomic and functional α and ß diversity for understory Passeriformes birds in southern China utilising cluster and ordination analyses. Subsequently, we analysed the effects of geographic distance, annual mean temperature, annual temperature range, annual mean precipitation, and annual precipitation range on diversity distribution patterns. In total, 9282 individuals belonging to 11 orders, 48 families, and 297 species were captured over 98,544 net hours, with Alcippeidae being the most abundant family in southern China. The understory bird communities of the 25 sites were categorised into six sub-regions of the Oriental Realm (Indo-Malayan Realm). The pattern in the distribution of taxonomic and functional ß-diversity of understory birds in southern China was consistent with zoogeographical regionalisation. Three distinct geographical groups were identified: Group 1 was located in the Min-Guang Coast and Hainan sub-regions; Group 2 was located in the East Hilly Plain, Southwest Mountains, and Western Mountains and Plateaus sub-regions; and Group 3 was located in the Southern Yunnan Mountain subregion. The most critical factors related to the distribution patterns of ß-diversity were geographical distance, annual mean temperature, and annual temperature range. Our results showed that the understory bird communities of the Southwest Mountain, East Hilly Plain, and Western Mountains, and Plateaus sub-regions were similar, as were those of the Min-Guang Coast and Hainan sub-regions. Our results underscore the joint roles of distance, temperature, and historical evolution in understory bird communities.

An empirical comparison of character-based and coalescent-based approaches to species delimitation in a young avian complex.

The process of discovering species is a fundamental responsibility of systematics. Recently, there has been a growing interest in coalescent-based methods of species delimitation aimed at objectively identifying species early in the divergence process. However, few empirical studies have compared these new methods with character-based approaches for discovering species. In this study, we applied both a character-based and a coalescent-based approaches to delimit species in a closely related avian complex, the light-vented/Taiwan bulbul (Pycnonotus sinensis/Pycnonotus taivanus). Population aggregation analyses of plumage, mitochondrial and 13 nuclear intron character data sets produced conflicting species hypotheses with plumage data suggesting three species, mitochondrial data suggesting two species, and nuclear intron data suggesting one species. Such conflict is expected among recently diverged species, and by integrating all sources of data, we delimited three species verified with independently congruent character evidence as well as a more weakly supported fourth species identified by a single character. Attempts to validate species hypothesis using Bayesian Phylogenetics and Phylogeography (BPP), a coalescent-based method of species delimitation, revealed several issues that can seemingly affect statistical support for species recognition. We found that θ priors had a dramatic impact on speciation probabilities, with lower values consistently favouring splitting and higher values consistently favouring lumping. More resolved guide trees also resulted in overall higher speciation probabilities. Finally, we found suggestive evidence that BPP is sensitive to the divergent effects of nonrandom mating caused by intraspecific processes such as isolation-with-distance, and therefore, BPP may not be a conservative method for delimiting independently evolving population lineages. Based on these concerns, we questioned the reliability of BPP results and based our conclusions about species limits exclusively on character data.

Morphology evolution and rheological properties of polybutadiene/polyisoprene blend after the cessation of steady shear.

The morphology evolution and rheological response of a near-critical composition polybutadiene/polyisoprene blend after the cessation of steady shear was studied with an ARES rheometer and a shear light scattering photometer equipped with an optical microscope in this work. The relationship between the morphology of the blend during the relaxation after the cessation of steady shear with different shear rates and their corresponding rheological properties was successfully established. It was found that the different shear-induced morphologies under steady shear would relax to the equilibrium states via varied mechanisms after the shear cessation. The average size of the dispersed domains in the coarsening process was influenced by the pre-shear history. The results indicated that the pre-shear history could slow down the growth rate of phase domains during the coarsening process. It had effect on the coarsening mechanism on the early stage of relaxation after the cessation of very strong shear when the homogenization effects were strong, but no effect on the late stage. The storage modulus G' increased significantly in the breakup process of the string-like phase. After all the string-like structures were broken up into small ellipsoids, then G' gradually decreased and finally approached to an invariant value. The characteristic rheological behavior can be attributed to the different structure on the relaxation process.

Species of Reticulipeurus Kéler, 1958 (Phthiraptera, Ischnocera, Oxylipeurus-complex) parasitic on species of Arborophila, with description of a new subgenus and three new species.

A new subgenus and three new species of parasitic lice (Phthiraptera: Ischnocera) in the Oxylipeurus-complex are described and illustrated. Forcipurellus new subgenus is part of the genus Reticulipeurus Kéler, 1958, and only includes species parasitic on partridges of the genus Arborophila Hodgson, 1837. The new species are: Reticulipeurus (Forcipurellus) diki new species ex Arborophila rubrirostris (Salvadori, 1879); Reticulipeurus (Forcipurellus) bracatus new species ex Arborophila atrogularis (Blyth, 1849); Reticulipeurus (Forcipurellus) longistylus new species ex Arborophila rufogularis guttata Delacour & Jabouille, 1928 and two other host subspecies. In addition, we redescribe the species Reticulipeurus (Forcipurellus) formosanus (Uchida, 1917) ex Arborophila crudigularis (Swinhoe, 1864) and Reticulipeurus (Forcipurellus) nitzschi Kéler, 1958 ex Arborophila torqueola torqueola (Valenciennes, 1825) and Arborophila torqueola millardi (Baker, 1921). Also, we briefly discuss four additional species that could not be described based on the specimens examined. A key to identify all species in the subgenus Forcipurellus is provided, as well as an emendation to include Forcipurellus in a previously published key to the Oxylipeurus-complex.

Distribution of birds in the high-altitude area of Mount Everest.

The species and abundance of birds in the high altitude area of Mount Everest decreased sharply with the increase of altitude. Alpine Choughs forage at altitudes of up to 8000 m and are the highest distribution of birds.

Genetic divergence and population demography of the Hainan endemic Black-throated Laughingthrush (Aves: Timaliidae, Garrulax chinensis monachus) and adjacent mainland subspecies.

Geographic variation in the Black-throated Laughingthrush (Garrulax chinensis) is examined to infer the influence of Pleistocene glacial oscillations on the genetic diversity of its subspecies. Mitochondrial evidence suggests that the endemic Hainan Island taxon, G. c. monachus, is monophyletic, whereas its closest continental relatives, G. c. chinensis and G. c. lochmius, are not. Multilocus coalescent analysis based on two mitochondrial and two nuclear intron loci indicates inter-subspecific genetic differentiation during the Pleistocene and substantial post-divergence genetic introgression from G. c. chinensis into G. c. lochmius. In contrast, G. c. monachus experienced no post-divergence gene flow despite occasional land-bridge contact with its continental relatives, suggesting its isolation may have been imposed by ecology as well as geography. It is probably reproductively isolated and should be treated as a distinct species.

Descriptions of six new species of slender-bodied chewing lice of the Resartor-group (Phthiraptera: Ischnocera: Brueelia-complex).

Six new species of chewing lice in the Resartor-group (Brueelia-complex) are described and illustrated. They are: Aratricerca cerata n. sp. ex Zosterops capensis Sundevall, 1850; Aratricerca macki n. sp. ex Melidectes princeps Mayr Gilliard, 1951 and Ptiloprora perstriata perstriata (de Vis, 1898); Aratricerca madagascariensis n. sp. ex Randia pseudozosterops Delacour Berlioz, 1931; Turdinirmoides janigai n. sp. ex Prunella collaris nipalensis (Blyth, 1843) and P. collaris fennelli Deignan, 1964; Turdinirmoides rozsai n. sp. ex Carpodacus subhimachala (Hodgson, 1836); and Timalinirmus curvus n. sp. ex Yuhina castaniceps plumbeiceps (Godwin-Austen, 1877). A key to the species of Aratricerca, Turdinirmoides and Timalinirmus is provided.

One new genus and three new species of the Penenirmus-complex (Phthiraptera: Ischnocera) from China, with resurrection of Picophilopterus Ansari, 1947.

Three new species of chewing lice of the Penenirmus-complex (Phthiraptera: Ischnocera) are described and illustrated from woodpeckers (Picidae) and barbets (Megalaimidae) occurring in China. They are: Picophilopterus blythipici new species from Blythipicus pyrrhotis sinensis (Rickett, 1897), Laimoloima ruiliensis new genus, new species from Psilopogon asiaticus asiaticus (Latham, 1790), and Laimoloima tandani new genus, new species from Psilopogon virens virens (Boddaert, 1783). In addition, we provide illustrations of Picophilopterus pici sensu lato ex Picus canus sordidior (Rippon, 1906), and we present evidence that justifies resurrecting the genus Picophilopterus Ansari, 1947 to include the species infesting woodpeckers and Neotropical barbets (Capitonidae). Also, we erect the new genus Laimoloima to include the species from Asian barbets (Megalaimidae). The taxonomic position of Penenirmus species from African barbets (Lybiidae) and honeyguides (Indicatoridae) is unresolved. An updated checklist of the species in the Penenirmus-complex parasitic on non-passeriform hosts is provided, including species of the genus Turnicola Clay Meinertzhagen, 1938.

Understanding the social impacts of enforcement activities on illegal wildlife trade in China.

Illegal wildlife trade enforcement is a cornerstone conservation strategy worldwide, yet we have a limited understanding on its social impacts. Using Chinese online wildlife seizure news (2003-2018), we evaluated the interactions among enforcement operations, news frequency, and social engagement (i.e., whistle-blowing) frequency. Our results showed that intensive enforcement operations, which commenced after 2012, have social impacts by increasing the frequency of all seizure news significantly by 28% [95% Confidence Interval (CI): 5%, 51%] and those via whistle-blowing by 24% [95% CI: 2%, 45%], when compared to counterfactual models where possible confounding factors were accounted for. Furthermore, we revealed the potential interaction between enforcement seizure news with and without social engagement, and the consequential social feedback process. Of the species identified from 'whistle-blowing' news, up to 28% are considered as high conservation priorities. Overall, we expanded our understanding of the enforcement impacts to social dimensions, which could contribute to improving the cost-effectiveness of such conservation efforts.

PHYLOGENETIC RELATIONSHIPS OF GUIMARAESIELLA AND PRICEIELLA (PHTHIRAPTERA: ISCHNOCERA) FROM BABBLERS AND NON-BABBLERS (PASSERIFORMES).

Babblers (Passeriformes: Leiothrichidae, Pellorneidae, Timaliidae) are parasitized by more genera of lice of the Brueelia complex than any other group of songbirds. However, the relationships of these louse groups are poorly known. We here try to resolve the relationships between Guimaraesiella (Guimaraesiella), Guimaraesiella (Cicchinella), and their putative sister group Priceiella by using mitochondrial cytochrome c subunit 1 (COI), 12S, and 16S sequences. Our data indicate that G. (Cicchinella) forms a monophyletic group of lice from babblers, but the relationship between G. (Guimaraesiella), G. (Cicchinella), and Priceiella could not be resolved. Moreover, the position of the third lineage of babbler-specific lice, containing only the aberrant species Guimaraesiella montisodalis, is unresolved. Morphologically, this species is different from all other Guimaraesiella in several characters and may represent a distinct lineage. We present some data indicating that (1) the Nanling Mountain range may be a biogeographical barrier to chewing lice and (2) host participation in mixed-species feeding flocks may influence host associations in Brueelia-complex chewing lice.