G. Chilton et Mr. Lein, SONG REPERTOIRES OF PUGET-SOUND WHITE-CROWNED SPARROWS ZONOTRICHIA-LEUCOPHRYS PUGETENSIS, Journal of avian biology, 27(1), 1996, pp. 31-40
Of 233 adult male White-crowned Sparrows Zonotrichia leucophrys pugete
nsis recorded in British Columbia and Washington, 25 (10.7%) were foun
d to have repertoires of two or three song types. This proportion is h
igher than any reported previously for this species. Within repertoire
s, most song type differences were minor, but some songs differed in t
heme and dialect type. Individuals sang few renditions of one song typ
e before switching to the other. We believe that the songs in an indiv
idual's repertoire have the same meaning, and that multi-song repertoi
res provide no selective advantage over a single song type in this spe
cies.