Green’s Dictionary of Slang

chirpiness n.

[chirpy adj./one chirps with pleasure]

happiness, cheerfulness.

[US]W.D. Howells Ital. Journal 248: He saluted us with a cricket-like chirpiness of manner, , and was greatly amazed to hear that we had come all the way from America.
[US]Harper’s Mag. 65 180: The chirpiness of the sparrow .