The effect of environmental conditions on the start of dawn singing of blackbirds (Turdus merula) and Bulbuls (Pycnonotidae)

Environmental pollution is known to influence bird behavior in many ways. In this study, the effect of noise, street lighting, moon light and weather conditions on the start of dawn singing of the two most common bird species in the area, bulbuls (Pycnonotus barbatus) and blackbirds (Turdus merula) is studied in a filed environment over a period of three autumn months. Results show that streetand moon lighting and the call for prayers by mosque loud speakers did not affect the start of singing compared to sunrise. Weather conditions (wind and rain) are the main factors that influenced the onset of singing in these two species. A relationship between sunrise and start of singing is established for blackbirds and bulbuls. Results show that sunlight,but not moonlight, affected the onset of dawn chorus in bulbuls and blackbirds. This study could serve as a record for similar future investigations on the influence of environmental conditions on birds behavior in the region.