Patterns and drivers of avian taxonomic and phylogenetic beta diversity in China vary across geographical backgrounds and dispersal abilities.

Geographical background and dispersal ability may strongly influence assemblage dissimilarity; however, these aspects have generally been overlooked in previous large-scale beta diversity studies. Here, we examined whether the patterns and drivers of taxonomic beta diversity (TBD) and phylogenetic beta diversity (PBD) of breeding birds in China vary across (1) regions on both sides of the Hu Line, which demarcates China's topographical, climatic, economic, and social patterns, and (2) species with different dispersal ability. TBD and PBD were calculated and partitioned into turnover and nestedness components using a moving window approach. Variables representing climate, habitat heterogeneity, and habitat quality were employed to evaluate the effects of environmental filtering. Spatial distance was considered to assess the impact of dispersal limitation. Variance partitioning analysis was applied to assess the relative roles of these variables. In general, the values of TBD and PBD were high in mountainous areas and were largely determined by environmental filtering. However, different dominant environmental filters on either side of the Hu Line led to divergent beta diversity patterns. Specifically, climate-driven species turnover and habitat heterogeneity-related species nestedness dominated the regions east and west of the line, respectively. Additionally, bird species with stronger dispersal ability were more susceptible to environmental filtering, resulting in more homogeneous assemblages. Our results indicated that regions with distinctive geographical backgrounds may present different ecological factors that lead to divergent assemblage dissimilarity patterns, and dispersal ability determines the response of assemblages to these ecological factors. Identifying a single universal explanation for the observed pattern without considering these aspects may lead to simplistic or incomplete conclusions. Consequently, a comprehensive understanding of large-scale beta diversity patterns and effective planning of conservation strategies necessitate the consideration of both geographical background and species dispersal ability.

Determining the level of extra-pair paternity in yellow-bellied prinias, a socially monogamous passerine.

Previous work based on molecular evidence has shown that most socially monogamous birds follow a genetic polyandrous mating system. However, our knowledge about avian mating systems is heavily biased toward the north temperate zone, with data on tropical birds remaining relatively scarce. This uneven distribution of both phylogenetic and spatial sampling has hampered our understanding and interpretation of results. In this study, we investigated the frequency of extra-pair paternity (EPP) in a tropical population of yellow-bellied prinias ( Prinia flaviventris) in Guangxi, southern China. A total of 129 individuals belonging to 24 nests were sampled, among which 12 out of 83 chicks (14.46%) in seven nests were found to be EPP offspring. In nests in which all nestlings were sampled, only five out of 56 chicks were EPP offspring, accounting for an unbiased EPP rate of 8.93%. This rate is below the average rate of EPP in the family Sylviidae. The possible causes of EPP in prinias and the occurrence of EPP in birds with high resource investment and intensive parental care are discussed. This study highlights the value of genome-wide markers in determining relatedness in a wild bird species without a reference genome.

A new record of the capped langur (Trachypithecus pileatus) in China.

The distribution of the capped langur (Trachypithecus pileatus) in China has become controversial since Shortridge's langur (Trachypithecus shortridgei) was upgraded to a full species. The capped langur is considered to be distributed in northeast India, Bangladesh, Bhutan, and northwest Myanmar only (Brandon-Jones et al., 2004; Choudhury, 2008, 2014; Das et al., 2008; Groves, 2001). In our field survey, however, we obtained photos of the capped langur, demonstrating its existence in China.

[The fauna and vertical distribution of birds in Mount Qomolangma National Nature Reserve].

From October 2010 to October 2012 (total 126 days), we used the line transect method combined with interviews applied during seven individual surveys to explore the bird resources of Qomolangma National Nature Reserve (QNNR). Based on the historical records and the present results, a total of 390 bird species belonging to 62 families and 18 orders, had been confirmed. Our results indicated that QNNR plays a vital and unique role in bird species preservation and scientific study, especially for endemic and endangered species. Species richness of both the Palearctic and Oriental realms were different, there was no overall significant difference (164 and 178, respectively). Species differences between the northern and southern slope of QNNR were especially remarkable. The northern slope was characterized with enriched endemic plateau species over small total number of bird species the southern flank held an abundance of bird species with complex composition. Moreover, on the southern slope, the peak of breeding birds richness occurred at 2,500~3,100 m a.s.l., supporting the mid-domain effect hypothesis. Meanwhile, as elevation increased, the richness of Oriental species decreased while that of Palearctic species increased. The percentages of Oriental and Palearctic species were similar at 3,100~4,000 m a.s.l.. Accordingly, we estimated that the boundary of Oriental realm and Palearctic realm was at 3,100~4,000 m a.s.l., and the species invasion from Palearctic to Oriental realm was more obvious. Perhaps most significantly, the specific distribution species along the vertical gradients also indicated their corresponding adaptation strategies.