The common blackbird Turdus merula is one of the most highly urbanized bird species. However, to date, the use of anthropogenic structures as nesting sites in the common blackbird is rarely documented, and the factors influencing its use of the anthropogenic structures as nesting sites remain unclear. In this study, we systematically quantified and determined the factors in- fluencing the use of anthropogenie structures as nesting sites in common blackbirds in a highly urbanized city of Hangzhou, Chi- na. We searched for nests of common blackbirds during four breeding seasons from 2010 to 2013. Among the 60 nests found, 34 nests were in anthropogenic structures such as wall ledges, air condition mounts, window canopies, cable poles, guardrails, eaves, balcony frames, flowerpots and flower shelves on balconies. We found that the available anthropogenic nest sites and the availa- ble nesting trees were main factors determining the use of anthropogenic structures as nesting sites in common blackbirds. In ur- ban environments, the amount of available anthropogenic nesting sites increased significantly, whereas the number of natural nesting sites reduced greatly. Our results suggest that common blackbirds can adjust their nest sites in response to urbanization and such nesting behavior shifts may aid them to colonize urban environments. From a management viewpoint, our results indi- cate that behavioral flexibility should be taken into account for effective urban wildlife management and conservation
Urbanization brings new selection pressures to wildlife living in cities,and changes in the life-history traits of urban species can reflect their responses to such pressures.To date,most of the studies investigating the impacts of urbanization on avian life-history traits are conducted in Europe and North America,while such studies are often lacking in quickly developing countries in Asia(e.g.,China).In this study,we examined the variations in reproductive life-history traits of Chinese Bulbuls(Pycnonotus sinensis)along the urbanization gradient in Hangzhou,China.We detected 234 natural nests of Chinese Bulbuls and continuously monitored them in two continuous breeding seasons from 2012 to 2013.We collected data on seven life-history traits(laying date,incubation period,nestling period,clutch size,egg volume,hatching success rate,and fledging success rate).We used infrared cameras to record the number of feedings per hour as the measure of food resources for the nestlings.We measured nest predation pressure by monitoring 148 natural breeding nests during breeding seasons and 54 artificial nests immediately after breeding seasons.We then calculated the urbanization synthetic index(USI)as a measure of the level of urbanization and examined its relationship with the seven life-history traits.We found that Chinese Bulbuls laid eggs significantly earlier with increasing USI.However,the other six life-history traits did not vary significantly with the USI.Moreover,the feeding frequency of chicks increased significantly with the USI,but the nest predation pressure of Chinese Bulbuls decreased significantly with the USI.Increased food resources and reduced nest predation pressure in cities may lead to earlier laying date of Chinese Bulbuls.Further study should test whether the earlier laying date of Chinese Bulbuls is the result of phenotypic plasticity or genetic change.
Xingmin ChenQin ZhangSisi LanQin HuangShuihua ChenYanping Wang
Nest predation is an essential factor affecting bird population density,reproductive ecology and life cycle.However,there are still contradictory results about how nest predation pressure changes with urbanization.One of the reasons for the controversy is that previous studies often use artificial nests to investigate nest predation,but the result of artificial nests is often biased and contrary to that of natural nests.Therefore,it is important to perform nest predation experiments simultaneously with both natural and artificial nests.In this study,we examined the change of nest predation pressure on the Chinese Bulbul(Pycnonotus sinensis)along the urbanization gradient in Hangzhou,China.We detected 148 natural nests of Chinese Bulbuls and continuously monitored them in two continuous breeding seasons from 2012 to 2013.After the breeding season,we placed artificial eggs in natural nests of Chinese Bulbuls to investigate the changes in nest predation pressure and used infrared cameras to record the predators.We then calculated the urbanization synthetic index(USI)as the measure of the degree of urbanization and examined its relationship with nest predation pressure.We found that no matter whether natural nests or artificial eggs were used,the nest predation pressure always decreased significantly with the degree of urbanization.The average height of shrubs within 10 m of the nest differed significantly between the predated and unpredated nests,which also affected the risk of nest predation.Our study highlights the importance of using natural and artificial nests simultaneously to conduct nest predation experiments,which can reduce the bias or errors caused by only using artificial nests.We also recommend the use of infrared cameras in future nest predation studies,which has obvious advantages in monitoring and identifying potential predators.
Xingmin ChenQin ZhangSisi LanShuihua ChenYanping Wang
Complete checklist records are essential to understand regional bird diversity and the status of the distribution of birds. The Zhejiang bird checklist was last presented as the Aves Branch of Zhejiang Fauna in 1990. Since then, many new records had been added, of which most remain unpublished. We have collected and examined all published and unpublished new records from Zhejiang habitats as well as those from the Aves Branch of Zhejiang Fauna. We have confirmed the evidence of the new records, which includes specimens, photographs, videos, sounds and tissue samples. We changed the Latin names of 131 species and subspecies and 41 Chinese names according to the new taxonomy and nomenclature. We provide an updated Zhejiang bird checklist for a total of 483 species and 24 subspecies, including 70 new species records, of which 47 species are reported for the first. Most of the new records are based on recent photographs taken by bird watchers.
