The impact of traffic noise and artificial light on vocal activity of Blackbird (Turdus merula)

Tamar Balgiashvili

Bachelor's thesis

Abstract:

The increasing number of studies devoted to the urbanization effects on the different animal and bird population are identifying 2 main pollution factors having the increasing trend and what is the most important – big impact of the environment – artificial light and urban noise pollution. Artificial light is suspected to cause a shift in timing and increase the song length together with the song intensity in most songbirds’ vocal activity. Urban noise can mask the part of the acoustical signals, change the melody and also affect the timing and intensity of the song. The aim of the below paper is to find out the statistically significant effect of the light and noise pollution on Common Blackbird`s vocal activity in the morning during the dawn chorus. The recordings from 2014 were analyzed from 4 types of localities - 1. With a light pollution, 2. With the noise pollution, 3. With the both light and noise pollution and 4. Control localities with no significant light or noise pollution. Avisoft SASLab and R statistical software were used for analyzing and evaluating recordings.The artificial light pollution was found as main cause in the earlier onset on the Blackbird`s dawn chorus as well as resulting significantly increased length and intensity of the song. According to the below results noise can not cause the statistically significant shift, nor affect the length and the intensity of the song. Nevertheless, with the combination with other independent variables (here artificial light) strengtheners the effect – Blackbirds on the localities effected by the combo of noise and light pollution start singing much earlier (some of them even 3 hours earlier) then the sunrise. The Combination of light and noise pollution also seem to decidedly contribute to prolonged dawn chorus song and maintenance of high intensity throughout the whole singing period.

Keywords

Blackbird (Turdus merula), Dawn Chorus, Light pollution, Noise Pollution, Urbanization

Language used: English

Date on which the thesis was submitted / produced: 25. 4. 2018

Thesis defence

• Supervisor: Ing. Petr Zasadil, Ph.D.
• Reader: Zuzana Musilová, Ph.D.

Czech University of Life Sciences Prague

Faculty of Environmental Sciences

Bachelor programme / field:
Environmental Scinces / Applied Ecology