Time-frequency analysis of bird songs and neurobehavioral study of the “Catbird Dumetella carolinensis”

Abstract

There is a commonality between the acquisition of spoken language in human infants and the acquisition of bird songs at the behavioral, neural, genetic, and cognitive levels. Similarities between how birds learn their language and how humans learn is believed to be fundamentally related to the way the brain works. Although the effects of the environment on hearing sensations, and hence the behaviors seems intuitive, it is not yet fully understood. In this paper, we use common digital recording systems to study bird songs in their natural habitat. Then by utilizing the principals of signal processing and spectral analysis individual syllabi are identified and studied for various songs. With the knowledge of the environment from direct measurement and the change in background noise level, the behavior of birds can be studied and documented. This technique was applied to recordings of Dumetella carolinensis (Gray Catbird) in the North East United States. It is shown that in spite of the natural instinct, the catbirds do not easily change their behavior at the onset of loud transient industrial sound. This may be related to the fact that the birds have already been exposed and have learned to live in noisy cosmopolitan environments.