TL;DR: The magnitude and speed of the decline of the Yellow-breasted Bunting is unprecedented among birds with a comparable range size, with the exception of the Passenger Pigeon, which went extinct in 1914 due to industrial-scale hunting.
Abstract: Persecution and overexploitation by humans are major causes of species extinctions. Rare species, often confined to small geographic ranges, are usually at highest risk, whereas extinctions of superabundant species with very large ranges are rare. The Yellow-breasted Bunting (Emberiza aureola) used to be one of the most abundant songbirds of the Palearctic, with a very large breeding range stretching from Scandinavia to the Russian Far East. Anecdotal information about rapid population declines across the range caused concern about unsustainable trapping along the species' migration routes. We conducted a literature review and used long-term monitoring data from across the species' range to model population trend and geographical patterns of extinction. The population declined by 84.3-94.7% between 1980 and 2013, and the species' range contracted by 5000 km. Quantitative evidence from police raids suggested rampant illegal trapping of the species along its East Asian flyway in China. A population model simulating an initial harvest level of 2% of thepopulation,andanannualincreaseof0.2%duringthemonitoringperiodproducedapopulationtrajectory that matched the observed decline. We suggest that trapping strongly contributed to the decline because the consumption of Yellow-breasted Bunting and other songbirds has increased as a result of economic growth and prosperity in East Asia. The magnitude and speed of the decline is unprecedented among birds with a comparable range size, with the exception of the Passenger Pigeon (Ectopistes migratorius), which went extinct in 1914 due to industrial-scale hunting. Our results demonstrate the urgent need for an improved monitoring of common and widespread species' populations, and consumption levels throughout East Asia.
TL;DR: The present study suggests that the ranges of Bull-headed Shrike L. bucephalus and Gray's Grasshopper Warbler L. fasciolata had expanded, although some previous studies do not support this trend.
Abstract: To examine the population trends of grassland and shrub birds in Hokkaido, we conducted line transect censuses in 2002 and 2003, in area where avifaunal studies had been performed in the 1970s and 1980s. To document the decline in the Yellow-breasted Bunting Emberiza aureola, birdwatching data were also analysed. The Yellow-breasted Bunting population has decreased drastically both in density and in distribution over the intervening thirty years. The decline in occupied breeding sites and in the population is continuing. Densities of Eurasian Skylark Alauda arvensis and Lanceolated Grasshopper Warbler Locustella lanceolata have also declined, although their range contractions are not yet severe. The ranges of Brown Shrike Lanius cristatus and Chestnut-eared Bunting E. fucata appear to have contracted. In contrast, data analysis revealed that the breeding range of Yellow Wagtail Motacilla flava has expanded in northern Hokkaido, but it is possible that the range had expanded in the past but had be...
TL;DR: The complete mitochondrial genome of E. aureola contained 37 genes (13 protein-coding genes, 2 rRNA genes, and 22 tRNA genes) and a non-c coding region (D-loop), which is similar to the typical mtDNA of vertebrates.
Abstract: The Emberiza pusilla is a common bunting with very wide geographical range. Here, the complete mitochondrial genome of E. pusilla (16,790 bp in length) has been analyzed for building the database. The results showed that it consisted of 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and 1 control region. The base composition of mtDNA was A (29.6%), G (14.8%), C (32.8%), and T (22.9%), so the percentage of A and T (52.5%) was slightly higher than G and C. All the genes in E. pusilla were distributed on the H-strand, except for the ND6 subunit gene and 10 tRNA genes, which were encoded on the L-strand.
TL;DR: Exposure of photosensitive birds to 24 h light-dark cycles with increasing photophase suggested that the threshold photoperiods of about 12 h in bunting and about 11 h in sparrow initiate follicular growth exceeding which the rate of growth increases with increasing Photophase, however, the thresholdphotoperiod was found to be response specific in Bunting.
Abstract: We studied the detailed pattern of seasonality in reproduction and the associated functions in the females of migratory yellow breasted bunting (Emberiza aureola) and resident tree sparrow (Passer montanus) under natural and artificial photoperiods. They exhibited seasonal cycles of ovarian development, moult and bill colour under natural photoperiods which were found linked to the annual solar cycle. Photosensitive birds of both the species, when exposed to 9L/15D, 12L/12D and 14L/10D for 18 months, showed follicular growth followed by regression and development of photorefractoriness only under artificial long photoperiods (12L/12D and 14L/10D). Fattening and body weight increase were noticed only in bunting exposed to long natural and artificial photoperiods. Both species exhibited complete postnuptial moult of body and primary feathers under long natural and artificial photoperiods (except primaries moult under 12L/12D in bunting) that progressed with gonadal regression suggesting their photoperiodic control. In addition, bunting also showed an incomplete prenuptial moult of body feathers during gonadal stimulation. Thus, the moult and body weight responses of bunting differed significantly when compared with those of sparrows. Exposure of photosensitive birds to 24 h light-dark cycles with increasing photophase suggested that the threshold photoperiods of about 12 h in bunting and about 11 h in sparrow initiate follicular growth exceeding which the rate of growth increases with increasing photoperiods. However, the threshold photoperiod was found to be response specific in bunting.