The Effects of Anthropogenic Ambient Noise and Habitat Vegetation on Common Yellowthroat Song

Urbanization not only decreases habitat availability for natural populations, but has also been shown to affect the behavior of animals. This study focuses on how anthropogenic, urban noise and habitat vegetation can affect the structure of common yellowthroat warbler (Geothlypis trichas) song. Ambient noise is concentrated in the low frequencies of noise and can mask the low song frequencies rendering them inaudible to the receiver. I predicted that yellowthroats will change the pitch and overall structure of their songs to avoid overlap with urban ambient noise. To test this possibility, I recorded yellowthroats songs and corresponding ambient noise, and measured vegetation cover and distance of the singing bird from the nearest road across a variety of acoustic habitats throughoutNew YorkState. I found that low frequency ambient noise was louder closer to major roads, but did not find that birds increased the minimum frequency of their songs to avoid low frequency ambient noise. However I did find a positive correlation between percent vegetation cover and frequency bandwidth of song. This suggests that yellowthroat song structure is shaped by the physical habitat and the resultant sound transmission properties. It appears that human disturbance in the form of vegetation alteration, instead of anthropogenic ambient noise, affects the song structure and singing behavior of common yellowthroats