William R Fish
BNA: This is the "dawn song" or "Regularly Repeated Vocalization" following BNA and W. J. Smith (1966. Communications and relationships in the genus Tyrannus.Publ. Nuttall Ornithol. Cl. 6). (CAM - 07Jan2005)
ML: Recording date unknown, but recordist known to be active between 1950 and 1972.