Hermit Thrush (Catharus guttatus) Science Article 7
Despite the Hermit Thrush’s wide distribution and exceptional singing ability, its vocal behavior is poorly known. In recorded samples from Arizona and New England, weshow that males have repertoires of 6 to 12 discrete song types. Those types can be presented in highly regular sequences, but the order varies among males, perhaps depending on context or motivation.
JAMES W. RIVERS and DONALD E. KROODSMA, J. Field Ornithol., 71(3):467-471