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Four new species of Guimaraesiella Eichler, 1949 are described and illustrated based on specimens collected in South China. They are: Guimaraesiella (Cicchinella) citreisoma new species ex Leiothrix lutea kwangtungensis Whistler, 1943 (Leiothrichidae); Guimaraesiella (Cicchinella) corrugata new species ex Alcippe hueti hueti David, 1874 (Leiothrichidae); Guimaraesiella (Cicchinella) petilorica new species ex Alcippe nipalensis nipalensis (Hodgson, 1837) (Leiothrichidae); and Guimaraesiella (Cicchinella) yuhinae new species from Yuhina flavicollis rouxi (Oustalet, 1896) (Zosteropidae); this is the first species of the Brueelia-complex recorded from a member of the Zosteropidae.

Collective action problems arise when two or more individuals can free ride on one another's efforts when investing jointly in a common good. Many collective action tasks in nature, such as parental care, require multiple stages of investments to complete a task, but how the costs of consecutive periods of investment and the excludability and diminishability of a collective good influence investment strategy remains poorly understood. Here, we first developed an evolutionary game-theoretical model to explore the theoretical consequences of sequential investment strategies in collective good problems. We then investigated cooperative parental care during both incubation and provisioning stages in the joint-nesting Taiwan yuhina, Yuhina brunneiceps, to test the key theoretical predictions of the model. We found that yuhina females that laid eggs earlier than other females invested more than they did in incubation (the first stage in the collective action problem). Intriguingly, but as predicted by our model, females that laid eggs earlier brought less food to nestlings in the joint brood during the nestling provisioning stage (the second stage in the collective action problem). This seemingly puzzling pattern can be explained by the fact that females that laid eggs earlier started incubation earlier and continued incubating eggs, which led to their offspring hatching earlier and being competitively superior (obtaining more food) at the nestling provisioning stage. Our study highlights the importance of understanding the complex nature of investment strategies parsed over different development stages in collective action problems.

Aeschynanthus (Gesneriaceae), a genus comprising approximately 160 species in subtropical Southeast Asia, has red, tubular flowers, typical of a sunbird pollination syndrome. A. acuminatus, the species that is distributed extending to the northern edge of the genus, where the specialized nectarivorous sunbirds are absent, possesses reddish-green flowers and a wide-open corolla tube, flowering time shifts from summer to winter and the species achieves high fruiting success. This atypical flower led us to investigate the pollination biology of this species. Three species of generalist passerines, Grey-cheeked Fulvetta (Alcippe morrisonia, Sylviidae), White-eared Sibia (Heterophasia auricularis, Leiothrichidae) and Taiwan Yuhina (Yuhina brunneiceps, Zosteropidae), were recorded visiting A. acuminatus flowers. Pollination effectiveness was quantified via conspecific pollen presence on stigmas and natural fruit set. The significantly high natural fruit set (60%) and conspecific pollen transfer rate (94%) indicate high reproductive success facilitated by the accurate pollen placement on the birds. The existence of copious (61 µL) and highly diluted (7%) hexose-dominant nectar, together with a major reflectance peak of corolla lobe in the long-wavelength red color spectrum, is consistent with the pollination syndrome of generalist passerines. The high pollination effectiveness of A. acuminatus due to the recruitment of generalist passerines as pollinators, and the specializations of floral traits to match generalist bird pollination, appear crucial in the successful colonization on islands such as Taiwan that lack specialized bird pollinators.

In China, the stripe-throated yuhina is mainly distributed in southwestern and the population is not abundant. In this study, we sequenced and characterized its complete mitochondrial genome. The c...

The complete mitochondrial of Black-chinned Yuhina is 17,817 bp in length and contained 13 protein-coding genes (PCGs), 2 rRNA genes, 22 tRNA genes, and 2 control regions. The overall base composit...

The Taiwan Yuhina (Yuhina brunneiceps) and White-eared Sibia (Heterophasia auricularis) are nectar-feeding babblers endemic to Taiwan. We describe the morphological features of the brush-tipped tongues of these species. The tongue divides into two parts and then into four parts towards the distal end for both species. The tongues of the Taiwan Yuhina and White-eared Sibia are specialized organs adapted for collection of nectar.

We sequenced the complete mitochondrial DNA genome of Yuhina diademata by means of polymerase chain reaction. The circle genome (17 834 bp in length) contained 13 protein-coding genes (PCGs), 2 rRNA genes, 22 tRNA genes, and 2 control regions (Dloop1 and Dloop2), which was similar to the other published mitogenome of Timaliidae species. Most PCGs began with ATG, while COI and ND2 genes started with GTG. Nine of the PCGs used complete (TAA) or incomplete (TA- or T--) stop codon, while ND1 and ND6 genes ended with AGA, COI gene ended with AGG, and ND6 gene with TAG. Overall base composition of the complete mtDNA was 30.30% A, 23.81% T, 31.72% C, and 14.17% G. All the PCGs in Y. diademata were distributed on the H-strand, except for the ND6 gene and eight tRNA genes which were encoded on the L-strand.

Distance sampling is usually preferred over uncorrected point counts for surveys of forest birds, but rarely has its accuracy been assessed against known numbers, particularly in tropical forests. We compared density estimates of eight species of breeding bird—Black-naped Monarch (Hypothymis azurea), Hill Blue Flycatcher (Cyornis banyumas), White-rumped Shama (Copsychus malabaricus), Puff-throated Bulbul (Alophoixus pallidus), Abbott's Babbler (Malacocincla abbotti), Puff-throated Babbler (Pellorneum ruficeps), White-browed Scimitar Babbler (Pomatorhinus schisticeps), and White-bellied Yuhina (Yuhina zantholeuca)—obtained through color-banding, nest finding, and territory mapping with those derived from distance methods in evergreen forest in northeastern Thailand. We also assessed the availability of birds to be detected using a closed-capture model and incorporated this with point-transect distance sampling. Abundance estimates from territory mapping and distance sampling were highly correlate...

Summary. The anting movements of nine passerine species were studied in captivity and in the wild. The birds applied acid-spraying Formicine ants (genera Lasius and Formica) to the plumage with the bill, with one wing extended and the tail brought round and often pressed against the wing. Only the Magpie deliberately applied the ants both to the tail and wing. In the Song Thrush, Blackbird, Starling, Western White-eye and Blue Tit, application was to the wing-tip alone, while the Pekin Robin, Black-chinned Yuhina and old-world Robin treated the wing-tip and also, incidentally, that part of the tail held close to it. The direct result of this behaviour is the anointing of the wing-tip with formic acid, the posturing of the tail facilitating this by making the wing-tip rigid. Anting is, apparently, one of the “feather maintenance” activities (preening, oiling, bathing, dusting, sunning) and, in the Pekin Robin and Song Thrush at least, the movements used in applying preen-oil to the wing-tip are very similar to, and probably homologous with the anting movements. Formic-acid possibly supplements the natural preen-oil but the exact function of the anointing remains to be discovered.

Mitochondrial sequences (2,379 bp) from cytochrome b, ND3, 12s and 16s rRNA were analyzed in order to reconstruct the phylogenetic relationships within the yuhinas (Yuhina), including the chestnut-faced babbler Stachyris whiteheadi which is endemic to the Philippines, the Japanese white-eye Zosterops japonicus, the chestnut-flanked white-eye Z. erythropleurus, and the oriental white-eye Z. palpebrosus. The results showed strong support for the idea that S.whiteheadi and three white-eye species form a clade embedded within the Yuhina clade. The robustness of the Yuhina/Philippine Stachyris/Zosterops clade rejected the validity of the monotypic genus Staphida, which was proposed for the striated yuhina Yuhina castaniceps based on its peculiar morphological traits. Sister group relationships between the striped-throated yuhina Yuhina gularis and the rufous-vented yuhina Yuhina occipitalis and between the whiskered yuhina Yuhina flavicollis and the white-naped yuhina Yuhina bakeri were discovered. The sympatric patterns of the above two sister groups in the Himalayas is most likely due to secondary contact. The molecular phylogeny also suggests that crestlessness was derived just once for the Zosterops/Philippine Stachyris clade. The Zosterops/Philippine Stachyris clade in our study also implies that an ancestor of Zosterops/Philippine Stachyris derived the ability to disperse over long distances, so that it could fly over the sea and arrive at the Philippines.

Background:\ud Although the highest diversity of birds occurs in tropical regions, little is known about the genetic mating systems of most tropical species. We describe microsatellite markers isolated in the chestnut-crested yuhina (Staphida everetti), endemic to the island of Borneo, and the grey-throated babbler (Stachyris nigriceps), widely distributed across Southeast Asia. Both species belong to the avian family Timaliidae and are highly social, putatively cooperatively breeding birds in which helpers attend the nests of members of their social group. We obtained DNA from individuals in social groups breeding in Kinabalu Park, Malaysian Borneo.\ud \ud Results:\ud We used a shotgun sequencing approach and 454-technology to identify 36 microsatellite loci in the yuhina and 40 in the babbler. We tested 13 primer pairs in yuhinas and 20 in babblers and characterized eight polymorphic loci in 20 unrelated female yuhinas and 21 unrelated female babblers. Polymorphism at the yuhina loci ranged from 3 to 9 alleles, observed heterozygosities from 0.58 to 1.00, and expected heterozygosities from 0.64 to 0.81. Polymorphism at the babbler loci ranged from 3 to 12 alleles, observed heterozygosities from 0.14 to 0.90 and expected heterozygosities from 0.14 to 0.87. One locus in the yuhina deviated significantly from Hardy–Weinberg equilibrium. We detected nonrandom allele associations between two pairs of microsatellite loci in each species.\ud \ud Conclusions:\ud Microsatellite markers will be used to describe the genetic mating system of these socially complex species and to measure genetic parentage and relatedness within social groups.

We studied the breeding ecology of Taiwan Yuhinas (Yuhina brunneiceps) at the Highlands Experiment Farm at Meifeng, National Taiwan University, in 1995 and from 1997–2002. The Taiwan Yuhina is a joint-nesting, cooperatively breeding species endemic to Taiwan. Males had significantly longer wing chords and tail lengths than females, probably due to sexual selection. Males also had a longer residence time at Meifeng than their female mates, which could be explained by philopatry being greater in males. Alpha males had a significantly longer residence time at Meifeng than beta males, but this was not the case for females, because females did not remain in the same group as males did after their mates disappeared. The breeding season was approximately 6 months long and multiple brooding was common. Nest building took 3 days, egg laying occurred over 3–4 days, the average incubation period was 14 days, and the nestling period was 12 days. Breeding success did not decrease later in the breeding season....

We investigated the effect of group size on incubation effort in Taiwan Yuhinas (Yuhina brunneiceps) at the Highlands Experimental Farm of National Taiwan University at Meifeng, Nantou County, central Taiwan, during 2000 and 2001. The Taiwan Yuhina is a joint-nesting, cooperatively breeding species endemic to Taiwan. We compared differences in parental investment among individuals of different sexes and status, explored the effect of group size on group incubation effort, and investigated whether individuals show compensatory reductions in care with respect to the number of females laying. Constancy of incubation increased as group size increased. Alpha females exhibited a significantly greater incubation effort than other individuals, but effort was similar among other group members. Both alpha males and females decreased their relative and absolute incubation effort as group size increased (i.e., there was a compensatory reduction in parental effort). However, beta pairs maintained a consistent...

Identifying the factors that modulate cooperative and competitive behaviours is the key to understanding social evolution. However, how ecological factors affect social conflict and their fitness consequences remain relatively unexplored. Here, using both a game-theoretical model and empirical data, we show that Taiwan yuhinas (Yuhina brunneiceps)--a joint-nesting species in which group members are unrelated--employ more cooperative strategies in unfavourable environmental conditions. Fighting duration was lower, fewer total eggs were laid and incubation was more likely to start after all females completed egg laying (which causes more synchronous egg hatching). Surprisingly, as a consequence, there were more surviving offspring in unfavourable conditions because the cooperative strategies resulted in fewer dead nestlings. To our knowledge, this study is the first theoretical analysis and empirical study demonstrating that an unfavourable environment reduces social conflict and results in better fitness consequences in social vertebrates.

Offspring often compete over limited available resources. Such sibling competition may be detrimental to parents both because it entails wasted expenditure and because it allows stronger offspring to obtain a disproportionate share of resources. We studied nestling conflict over food and its resolution in a joint-nesting species of bird, the Taiwan yuhina ( Yuhina brunneiceps ). We show that adult yuhinas coordinate their feeding visits, and that this coordination limits competition among nestlings, leading to a ‘fairer’ division of resources. Transponder identification and video-recording systems were used to observe adult feeding and nestling begging behaviours. We found that: (i) yuhinas feed nestlings more often in large parties than in small parties; (ii) feeding events occurred non-randomly in bouts of very short intervals; and (iii) food distribution among nestlings was more evenly distributed, and fewer nestlings begged, during large-party feeding bouts compared with small-party feeding bouts. To our knowledge, this is the first study in a cooperative breeding species showing that adults can influence food allocation and competition among nestlings by coordinating their feeding visits. Our results confirm the hypothesis that the monopolizability of food affects the intensity of sibling competition, and highlight the importance of understanding the temporal strategies of food delivery.

The relative importance of direct and indirect fitness and, thus, the role of kinship in the evolution of social behavior is much debated. Studying the genetic relatedness of interacting individuals is crucial to improving our understanding of these issues. Here, we used a seven-year data set to study the genetic structure of the Taiwan yuhina (Yuhina brunneciceps), a joint-nesting passerine. Ten microsatellite loci were used to investigate the pair-wised relatedness among yuhina breeding group members. We found that the average genetic relatedness between same-sex group members was very low (0.069 for male dyads and 0.016 for female dyads). There was also a low ratio of closely-related kin (r>0.25) in the cooperative breeding groups of yuhinas (21.59% and 9.68% for male and female dyads, respectively). However, the relatedness of male dyads within breeding groups was significantly higher than female dyads. Our results suggest that yuhina cooperation is maintained primarily by direct fitness benefits to individuals; however, kin selection might play a role in partner choice for male yuhinas. Our study also highlights an important, but often neglected, question: Why do animals form non-kin groups, if kin are available? We use biological market theory to propose an explanation for group formation of unrelated Taiwan yuhinas.