Do Birds Turn into Clams? Curious 'Phenological Trivia'

Ancient Chinese divided the 'Cold Dew' solar term into three periods: 'First, wild geese arrive as guests; second, sparrows enter the great waters and become clams; third, chrysanthemums bloom yellow.' The phrase 'sparrows enter the great waters and become clams' means that ancient people observed fewer birds in late autumn, while clams suddenly appeared in large numbers by the sea. The patterns on the clam shells also resembled bird feathers, leading them to naively believe that sparrows that fell into the sea during the Cold Dew period transformed into clams.