Bb. Dewolfe et Lf. Baptista, SINGING BEHAVIOR, SONG TYPES ON THEIR WINTERING GROUNDS AND THE QUESTION OF LEAP-FROG MIGRATION IN PUGET-SOUND WHITE-CROWNED SPARROWS, The Condor, 97(2), 1995, pp. 376-389
Singing behavior in Zonotrichia leucophrys pugetensis on their winteri
ng grounds in California was studied. Additionally syllables from song
s of overwintering birds were compared to syllables in songs recorded
previously on their breeding grounds in an effort to identify winterin
g grounds of dialectal populations. Much singing was recorded from rec
ently arrived birds in the fall. At least some spontaneous singing was
recorded every month of the year. However, singing decreased in Decem
ber and increased in February, probably in response to increasing day
lengths. Song development was complete or almost so in some juveniles
recorded upon arrival in California. At least some birds responded to
playback with singing during all months on the wintering grounds, howe
ver, responses peaked during arrival in the fall and before departure
for the breeding grounds in the spring. At each wintering locality, se
veral dialects were sung, indicating that more northerly breeding popu
lations do not leap-frog and winter south of more southerly breeding p
opulations. The resident Z. l. nuttalli sometimes borrow elements from
wintering Z. l. pugetensis to construct ''hybrid'' themes. However, s
yllables from alien dialects are soon lost from the population due to
match-countersinging by Z. l. nuttalli males.