Tweet tweet…Chirp chirp..
In a world dominated by growing human population and rapid urbanization, it is not everyday that we wake up to this music of our feathered friends. Referred to as bird songs, it is not only soothing to ears, but is also important to birds in communication, territory defense, and mating. Living in an urbanized environment is as challenging and stressful to birds as it is for us. The noise creates stressful conditions, compelling them to sing louder. Studies on a few species have shown that birds not only sing louder, but also sing with higher pitches in an urban environment when compared to their rural counterparts.
The ability of the birds to adjust their songs in response to changes in the environment, also known as song plasticity, was investigated in the Eastern wood pewee or Contopus virens by a group of researchers in the USA. Songs recorded from urban parks measured in relation to the background noise revealed that adjustment of the song is closely aligned with fluctuations in noise; and in the absence of noise, the songs return to their natural state. Studies on species such as Great tits, Chaffinch, Robins and Blue tits have yielded similar results.
One thing that we can infer from these studies is that it is important to conserve the habitat in which a species lives as the ecological factors have a significant impact on the behavior and physiology of the birds. In other words, habitat conservation is crucial for conservation of species.
Ongoing research at the Max Planck Centre for Ornithology at Germany seeks to understand the consequences of man-made noise on the natural world. This has led to some interesting questions. Is adaptation by birds to changing environmental conditions driven by evolutionary pressures? Is evolution in action? Future research might help us gain insight into how bird songs and evolution go hand in hand in a changing environment.