“We know that the time of morning is punctuated by the singing of birds,” he said. away from the equatorial regions,” Cassone said. “Fifty years from now, there’ll be huge climatic changes,” he con. Feb 19, 2015. Evidence that birds sing at higher frequencies in noisy cities than they do in quieter rural sites has now been found in numerous species. Stamp News Now listing of the USPS Stamp Issues…