Phylloscopus Research Articles

Breeding Distribution of the Isolated Iijima's Leaf Warbler Population in the Tokara Islands and its Ecological, Morphological, and Genetic Characteristics

Breeding Distribution of the Isolated Iijima's Leaf Warbler Population in the Tokara Islands and its Ecological, Morphological, and Genetic Characteristics

Breeding ecology of Eastern Crowned Leaf Warbler and brood parasitism by the Oriental Cuckoo

Breeding ecology of Eastern Crowned Leaf Warbler and brood parasitism by the Oriental Cuckoo

Extraordinary occurrence of Pallas’s leaf warbler (Phylloscopus proregulus Pallas, 1811) in Bulgaria and the Balkan Peninsula in the autumn and winter of 2022/2023

Four Pallas’s leaf warblers (Phylloscopus proregulus) were captured at Durankulak ringing camp, NE Bulgaria, in frames of four days between 12 and 16 October 2022. The species is a rare vagrant in Bulgaria and neighbouring Balkan countries. It has not been captured and ringed neither at Durankulak nor elsewhere in Bulgaria until now. Annual population fluctuations and weather conditions are discussed as possible explanations for that influx.

Limited song-mixing without genomic gene flow in a contact zone between two songbird species.

Song is considered to play an important role in the maintenance of prezygotic reproductive isolation between closely related songbird species. Therefore, song-mixing in a contact zone between closely related species is often considered as evidence of hybridization. The Sichuan Leaf Warbler Phylloscopus forresti and the Gansu Leaf Warbler P. kansuensis, which diverged two million years ago, have formed a contact zone in the south of the Gansu Province of China, where mixed-songs have been observed. In this study, we investigated the potential causes and consequences of song-mixing by integrating bioacoustic, morphological, mitochondrial, and genomic data with field ecological observations. We found that the two species display no apparent morphological differences, while their songs differ dramatically. We demonstrated that approximately 11% of the males in the contact zone sang mixed-songs. Two males singing mixed-song were genotyped, and both were found to be P. kansuensis. Despite the presence of mixed-singers, population genomic analyses detected no signs of recent gene flow between the two species, although two possible cases of mitochondrial introgression were identified. We conclude that the rather limited song-mixing does not lead to, or result from, hybridization, and hence does not result in the breakdown of reproductive barriers between these cryptic species.

Identification and molecular classification of passeriform birds in Kabul province

It is thought that the passiform order of bird has monophyletic origin.. However, new studies show that many passerine families are not monophyletic in traditional classifications, and a more complete understanding of Passeriform phylogeny is possible only by conducting extensive molecular studies. Therefore, this molecular study was conducted to evaluate the passiform birds of Kabul Province, Afghanistan. Samplings were collected from ten already marked stations during three stages in Kabul province in 2019 and 2021 years, including Deh Sabz, Bagrami, Sarubi, Khak Jabar, Shekar Dara, Gol Dara, Paghman, Char Asiyab, Andrabi Road and Kafroshi. Totally 190 samples were taken using a net. Miss net was collected and 110 samples were taken to the laboratory. After the morphological studies, it was identified by the identification key that all the species belong to the Passeriform order. These species belong to 13 families, 23 genera and 35 species, of which the family of yellow-winged moths is the most diverse with 7 species and the family of sparrows is the most abundant with 45 individuals. After performing morphometry, the samples were transferred to the laboratory for molecular studies and DNA extraction and COX1 gene sequencing to identify the species in the tree drawn by Bayesian method which shows the position of genera and species within families and superfamilies. In this study, genus Passer with four species, genus Motacilla with one species, genus Carduelis with one species, genus Emberiza with six species and genus Serinusa with one species were included in the superfamily Passerioiodea. The genus Corvus with one species and the genus Lanius with one species were included in the Corvida clade. Two species of the genus Luscinia with one species of the genus Muscicapa and one species of the genus Acridotheres were included in the superfamily Muscicapoidea. Two species of the genus Hirundo, one species of the genus Phylloscopus, one species of the genus Ripria, one species of the genus Sitta, one species of the genus Sylvia and one species of the genus Eremophila were included in the superfamily Sylvioidea.

The Effect of Range Migration on the Annual Cycles of Leaf Warblers (Phylloscopus) in Northwestern Siberia

The Effect of Range Migration on the Annual Cycles of Leaf Warblers (Phylloscopus) in Northwestern Siberia

Wintering of Leaf Warblers (Phylloscopus Boie, 1826) in Gangajalghati: First photographic evidence of four species from Northern Bankura, West Bengal, India

Leaf warblers are small insectivorous passerine birds that belong to the genus Phylloscopus (Boie, 1826) and exhibit great similarity in plumage and morphology. These song birds have been reported with the maximum diversity in the eastern Himalayas and southern China. No comprehensive studies with photographic evidence on Phylloscopus have been conducted so far in the Southern parts of West Bengal including Bankura district in India. Three types of habitats of Gangajalghati village in Bankura district were surveyed during winter for 8 months between November 2015 and February 2017 and bird counts were recorded and photographed. A total of 49 individuals from four species of Phylloscopus were recorded. The most abundant species recorded in the study was the dusky warbler (Phylloscopus fuscatus, Blyth, 1842) followed by greenish warbler (Phylloscopus trochiloides, Sundevall, 1837), common chiffchaff (Phylloscopus collybita, Vieillot, 1817) and Hume's leaf warbler (Phylloscopus humei, Brooks, 1878). Further, the prey abundance of leaf warblers (lepidopteran caterpillar and other arthropods) were determined in the early winter session (first week of November and December). The study recorded maximum bird abundance and species richness in the wetland associated habitats with higher prey abundance followed by barren land and agriculture field. The work documented the visit of dusky and greenish warblers to Bankura for the first time in the past 40 years and recorded the wintering of common chiffchaff and Hume's leaf warblers as the first evidence from the district.

Птицы озерных котловин южной части хребта Черского.

New data and analysis of the avifauna and bird species abundance are given for the lake systems of the southern part of the Chersky mountain ridge. In August - October of 2018 and in June and August of 2021, bird studies of lake basins of Ui, Momontay, Malyk, Darpir and Urultun lakes, situated at altitudes of 818-1234 meters above the sea level, were performed. 81 bird species were registered, of which 69 were recorded during breeding season, including 56 species referred to breeding and 13, to summering species. In comparison to the bird fauna of neighboring mountain areas, the avifauna of the studied lake systems is characterized by low species diversity, low percentage of widely-distributed species, and high percentage of boreal-hypoartcic and hypoarctic types of zonal- landscape distribution with clearly dominating species of the Siberian origin. Species content of the studied area is similar to that of the subalpine belt of Yakutia's northern mountains in the presence of Long-toed Stint, Red-throated Pipit and Pallas' Reed Bunting as well as, contrary to the subalpine belt of the Kolyma Highland, in the absence such species as Pine Grosbeak, Siberian Rubythroat, Pallas' Leaf Warbler, and Arctic Warbler on these elevations. On the other hand, the presence of such species as Ringed Plover and Dusky Warbler and the absence of Bluethroat is similar to the bird fauna of the Kolyma Highland subalpine belt. High abundance of both Beringian and Green-headed Yellow Wagtails sharing their habitats appeared to be a unique feature of the studied area. Confirmed breeding of Fieldfare on the elevations over 1000 m above the sea level significantly increases the knowledge on the distribution and ecology of this species.

Distribution of Kamchatka Leaf Warbler Phylloscopus examinandus during Breeding Season in Hokkaido, Japan

Distribution of Kamchatka Leaf Warbler <i>Phylloscopus examinandus</i> during Breeding Season in Hokkaido, Japan

Seasonality and social factors, but not noise pollution, influence the song characteristics of two leaf warbler species.

Changes in the acoustic signalling of animals occupying urban ecosystems is often associated with the masking effects of noise pollution, but the way in which they respond to noise pollution is not straightforward. An increasing number of studies indicate that responses can be case specific, and some species have been found to respond differently to high levels of natural versus anthropogenic noise, as well as different levels of the latter. While the perception of noise between species may vary with its source, amplitude and temporal features, some species may possess broader environmental tolerance to noise pollution, as they use higher frequency vocalizations that are less masked by low-frequency urban noise. In this study, we explored the song variation of two closely related leaf warblers, the Common Chiffchaff Phylloscopus collybita and the Willow Warbler Phylloscopus trochilus, inhabiting urban green spaces and nonurban forests. The main goal of our study was to evaluate the impact of moderate levels of noise pollution on the songs of species which use higher frequency vocalizations and large frequency bandwidth. Previous studies found that the Common Chiffchaff modified their song in response to intense noise pollution, while no such data is available for the Willow Warbler. However, the majority of urban green spaces, which serve as wildlife hot spots in urban environments are usually polluted with moderate noise levels, which may not mask the acoustic signals of species that communicate with higher frequency. We analysed the spectral and temporal song parameters of both warblers and described the ambient noise present in males’ territories. Additionally, we looked at the social and seasonal aspects of bird song, since there is more than just noise in urban ecosystems which may affect acoustic communication. We found no evidence for noise-related bird song divergence in either species, however, we showed that social factors, time of day and season influence certain Common Chiffchaff and Willow Warbler song characteristics. Lack of noise-related bird song divergence may be due to the relatively low variation in its amplitude or other noise features present within the song frequency range of the studied species. Similar results have previously been shown for a few songbird species inhabiting urban ecosystems. Although in many cases such results remain in the shadow of the positive ones, they all contribute to a better understanding of animal communication in urban ecosystems.

Most Genomic Loci Misrepresent the Phylogeny of an Avian Radiation Because of Ancient Gene Flow.

Phylogenetic trees based on genome-wide sequence data may not always represent the true evolutionary history for a variety of reasons. One process that can lead to incorrect reconstruction of species phylogenies is gene flow, especially if interspecific gene flow has affected large parts of the genome. We investigated phylogenetic relationships within a clade comprising eight species of passerine birds (Phylloscopidae, Phylloscopus, leaf warblers) using one de novo genome assembly and 78 resequenced genomes. On the basis of hypothesis-exclusion trials based on D-statistics, phylogenetic network analysis, and demographic inference analysis, we identified ancient gene flow affecting large parts of the genome between one species and the ancestral lineage of a sister species pair. This ancient gene flow consistently caused erroneous reconstruction of the phylogeny when using large amounts of genome-wide sequence data. In contrast, the true relationships were captured when smaller parts of the genome were analyzed, showing that the “winner-takes-all democratic majority tree” is not necessarily the true species tree. Under this condition, smaller amounts of data may sometimes avoid the effects of gene flow due to stochastic sampling, as hidden reticulation histories are more likely to emerge from the use of larger data sets, especially whole-genome data sets. In addition, we also found that genomic regions affected by ancient gene flow generally exhibited higher genomic differentiation but a lower recombination rate and nucleotide diversity. Our study highlights the importance of considering reticulation in phylogenetic reconstructions in the genomic era.[Bifurcation; introgression; recombination; reticulation; Phylloscopus.]

Non-breeding season records of the Alpine Leaf Warbler Phylloscopus occisinensis

We present non-breeding season records of the recently named Alpine Leaf Warbler Phylloscopus occisinensis from Bangladesh (four individuals) and northern Thailand (one). Identification was based on mitochondrial DNA assay of feathers or blood from birds handled during ringing. Tickell's Leaf Warbler P. affinis (sensu lato) was abundant in scrub and scattered trees at the margins of wetlands in north-east Bangladesh, whilst the record from Thailand represents a significant eastwards extension of the previously recorded wintering range. Further sampling in South and South-East Asia will be necessary to resolve the winter ranges of the taxa affinis and occisinensis.

横浜自然観察の森におけるイイジマムシクイPhylloscopus ijimae の観察記録

横浜自然観察の森におけるイイジマムシクイPhylloscopus ijimae の観察記録

Convergence in Passeriformes species of Kabul province using COX1 mitochondrial gene sequence

The aim of this survey is study of Passeriformes of Kabul (Afghanistan). Until now it was thought that these birds are monophyletic. However, recent studies determined that many families of Passeriformes are not monophyletic in traditional classification and extensive molecular investigations are the only way to clarify the phylogeny of this group of birds. Sampling was performed from ten stations in the province of Kabul: ten green, Bagram, Surobi, KhakJabbar, Shekardareh, Gol dare, Paghman, Char Asiab, Anderabei and Kafrushy, in three stages between 2015 and 2016, 190 samples were captured using Mist net, and 148 samples were transported to the laboratory. 110 samples of them were belonged to Passeriformes and 38 samples were not. Sparrows that were caught were from 13 families, 23 genera and 35 species of Passeriformes, that family Emberizdae with seven species has the greatest diversity and family Passeridae with 45 individuals has the highest frequency. After morphometric measurements, the samples were transported to the laboratory for molecular studies, DNA was extracted and COX1 gene was sequenced for identification of species and genetic distances. The Bayesian tree indicated the position of species and genera within families and super families. In this study, genus Passer with four species, genus Motacilla with only one species, genus Carduelis with single species, genus Emberiza with six species and genus Serinusa with single species were positioned in superfamily Passerioiodea. Genus Corvus with a single species and genus Lanius with one species were located in clade Corvida. Two species of genus Luscinia, one species of genus Muscicapa and one species of genus Acridotheres were located in superfamily Muscicapoidea. Two species of the genus Hirundo, one species of genus Phylloscopus, one species of genus Ripria, one species of the genus Sitta, one species of genus Sylvia and one species of genus Eremophila were positioned in superfamily Sylvioidea.

Five new mitogenomes of Phylloscopus (Passeriformes, Phylloscopidae): Sequence, structure, and phylogenetic analyses

The genus Phylloscopus belongs to the order Passeriformes and subfamily Phylloscopinae within the family Sylviidae. Phylloscopus, a small insectivore widely distributed in the old world, includes 66 species and 112 subspecies. We identified five new Phylloscopus mitogenomes: P. tenellipes (16,904 base pairs (bp), MK390475), P. coronatus (16,905 bp, MK533705), P. borealis (16,881 bp, MK390476), P. schwarzi (16,920 bp, MK411584), and P. borealoides (16,904 bp, MN125373). All contained 37 genes, including 13 protein-coding genes, two rRNA genes, 22 tRNA genes, and two control regions. Seven Phylloscopus species were compared to the five new mitogenomes and the published complete P. inornatus and P. proregulus mitochondrial sequences. The genetic distance of 13 single protein-coding genes exhibited low variation within all seven Phylloscopus mitogenomes. Based on the Ka/Ks ratios, the molecular evolution patterns of single protein-coding genes were relatively consistent among Phylloscopus bird species. Phylogenetic analysis verified that subspecies of the Pale-legged Leaf Warbler P. tenellipes borealoides could be promoted to the Sakhalin Leaf Warbler P. borealoides. Gene order and genome organization information is useful to understand evolutionary relationships among Phylloscopus species. The complete mitogenomes of these five Phylloscopus species provide genetic markers for species identification, population genetics, and phylogeographic studies of birds.

Notes on the birds of Isabel, Solomon Islands, including the first record since 1927 of Island Leaf Warbler Phylloscopus maforensis

The birds of the Solomon Islands have received ample historical attention by explorers, collectors and researchers. Despite this, knowledge of the region's avifauna is categorised by BirdLife International as ‘poor’ and multiple new populations of birds have been found in recent years, highlighting our incomplete knowledge of the region's avifauna. Here, we present new information on the elevational occurrence, abundance and natural history for ten bird species we observed on Isabel Island. The data we present are based on three weeks of field work at three field sites that included the restricted montane forests above 1,000 m elevation on the Kubonitu-Sasari massif. In this poorly known montane area we observed multiple Island Leaf Warblers Phylloscopus maforensis for the first time since it was discovered on Isabel in 1927.

Seasonal and diurnal increases in energy stores in migratory warblers at an autumn stopover site along the Asian–Australasian flyway

In contrast to the rapidly growing body of knowledge on migratory routes, wintering grounds and timing of annual life cycle events of migratory birds, knowledge on how migratory songbirds refuel at stopover sites along the Asian–Australasian flyway has increased only slowly, despite the fact that migrant birds show declining trends along it. We analysed the amount and variation of energy stores between species, variation of energy stores within the day and within the season, and estimated flight ranges of ten closely related warbler species (genera Acrocephalus, Arundinax, Locustella and Phylloscopus), captured at a stopover site in the Russian Far East during the autumn migration. We found significant differences in the species’ energy stores, with Pallas’s Leaf Warbler Phylloscopus proregulus having by far the highest. All species increased their energy stores within the day, and eight species increased their energy stores within the season. Individuals with the highest estimated flight ranges were able to cover a distance of 470 km during one nocturnal flight bout, which would have resulted in a minimum of nine stopovers before the birds reached their wintering grounds. We assume that a combination of factors determines the variation in energy stores between these species. We discuss the potential for these birds to exploit different habitats and refuelling strategies according to the distribution of species-specific refuelling habitats, and a variety of food resources, along the migratory route. This study is the first to provide information on energy stores, refuelling strategies and flight ranges for a set of closely related songbird species migrating along the Asian–Australasian flyway.

"Ghost Introgression" As a Cause of Deep Mitochondrial Divergence in a Bird Species Complex.

In the absence of nuclear-genomic differentiation between two populations, deep mitochondrial divergence (DMD) is a form of mito-nuclear discordance. Such instances of DMD are rare and might variably be explained by unusual cases of female-linked selection, by male-biased dispersal, by "speciation reversal" or by mitochondrial capture through genetic introgression. Here, we analyze DMD in an Asian Phylloscopus leaf warbler (Aves: Phylloscopidae) complex. Bioacoustic, morphological, and genomic data demonstrate close similarity between the taxa affinis and occisinensis, even though DMD previously led to their classification as two distinct species. Using population genomic and comparative genomic methods on 45 whole genomes, including historical reconstructions of effective population size, genomic peaks of differentiation and genomic linkage, we infer that the form affinis is likely the product of a westward expansion in which it replaced a now-extinct congener that was the donor of its mtDNA and small portions of its nuclear genome. This study provides strong evidence of "ghost introgression" as the cause of DMD, and we suggest that "ghost introgression" may be a widely overlooked phenomenon in nature.

Phylogenetic relationship and characterization of the complete chloroplast genome of the alpine leaf-warbler in Qinghai-Tibet Plateau

The Alpine Leaf-warbler (Phylloscopus occisinensis) is a small-sized and poorly-known songbird endemic to China. In this study, we sequenced and described the whole mitochondrial genome of the Alpine leaf-warbler. The entire mitochondrial sequence was determined by long-range PCR and conserved primer walking approaches. The results demonstrated that the whole mitochondrial genome of P. occisinensis was 16,879 bp in length with 53.1% A + T content; the genome harboured the same gene order as that of other passerine birds, including 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes and non-coding control region. The control region (D-loop) of P. rubicilloides include two portions that one was located between tRNA-Gln and tRNA-Phe (219 bp in length) and the other is between tRNA-Thr and tRNA- Pro (1087 bp in length), which is similar to other Leaf-warblers. Phylogenetic analysis indicated that the genome of Phylloscopus species clustered within a clade and is closer related to Aegithalidae species than Paridae species. These mitochondrial data are potentially important for the further studies on molecular evolution and conservation genetics on leaf warbler species.

Intraspecific Differentiation of the Oriental Cuckoo (Cuculus optatus) within the Range: Relationship with the Abundance of Host Species

The distribution of C. optatus host-specific races within the breeding range has been analyzed. It has been found that these races are geographically separated: their distribution areas coincide with regions where the population density of corresponding race-forming host species (leaf warblers) is increased. The abundance of the brood parasite depends on the population density of race-forming host species and of accessory hosts (species laying pure white eggs). The group of accessory hosts plays an important role in areas where the proportion of race-forming species in the total population of leaf warblers is relatively small.