First recorded (as “Reginella campagnola”) by Carlo Buti (1939).
Also recorded by Kate Smith (1940).
Hit versions by The Andrews Sisters (US #7 1940), Glenn Miller & His Orchestra (US #1 1940).
From the wiki: “‘The Woodpecker Song’ (‘Reginella campagnola’) was originally an Italian song, written by Eldo Di Lazzaro, and first recorded by Carlo Buti in 1939. English lyrics were written by Harold Adamson and the song became a US hit in 1940, recorded by Glenn Miller and His Orchestra, The Andrews Sisters, and Kate Smith the same year. The Glenn Miller recording featured Marion Hutton on vocals and reached #1 on the Billboard charts in 1940.”