Dr Chandrashekaran has done significant work on biological rhythms in plants and animals. His work on the circadian rhythms of tropical mammals, especially the bats which exchange ultrasonic sound information in the cave environment, has led to an understanding of the existence of social synchronization of these rhythms. Another notable contribution of Prof. Chandrashekaran is elucidation of 'eclosion clock' in the fruit-fly Drosophila.