Microgeographic Song Variation in the Chinese Bulbul (Pycnonotus sinenesis) in Urban Areas of Hangzhou City

Between May and August 2002, microgeographic song variations of the Chinese Bulbul (Pycnonotus sinensis) were studied in Hangzhou, capital of Zhejiang Province in eastern China. We recorded 511 morning songs of 80 male Chinese Bulbul at eight locations: four locations in extensive mixed forest and 4 locations in urban woodlots, within an area of about 60 km2. We analysed the acoustic characteristics of typical sentences and their syllables of 160 songs, and randomly selected 20 songs for each location. The results showed that the Chinese Bulbul has obvious microgeographical song variations; specifically, that eight microgeographic song dialects were found in our survey area and each dialect had a typical song sentence. The microgeographical song variations of the Chinese Bulbul in Hangzhou occurred at different levels of acoustic characteristics, such as hearing, oscillogram, syllable composition, sonagram and spectrum. Obvious boundaries between microgeographical song dialects and also multibilingual individuals could be found in some survey locations. Additionally, the mixed areas in where individuals with different microgeographical song dialects occurred could be also found in our survey. The occurrence of microgeographical song dialects in the Chinese Bulbul might be related to individual dispersal of and changes of the habitats in urban areas.