Wa. Searcy, SOUND-PRESSURE LEVELS AND SONG PREFERENCES IN FEMALE RED-WINGED BLACKBIRDS (AGELAIUS-PHOENICEUS) (AVES, EMBERIZIDAE), Ethology, 102(3), 1996, pp. 187-196
Female red-winged blackbirds (Agelaius phoeniceus) were tested for res
ponse to songs of male red-winged blackbirds differing in sound-pressu
re level (SPL) of playback. Subjects gave significantly more copulatio
n-solicitation displays in response to playback of songs at 85 dB SPL
than to playback of the same songs at 72 dB SPL. The strength of the p
reference, as judged by the ratio of response to high and low SPL play
back (1.15:1), was lower than that of preferences for high SPL shown b
y insects and anurans. Female red-winged blackbirds responded preferen
tially to a conspecific song relative to a heterospecific imitation, e
ven when the imitation was presented at an SPL 13 dB higher than that
of the conspecific song. By contrast, female redwings did not maintain
a preference for multiple conspecific song types over single types wh
en the single song types were presented at the higher SPL. These resul
ts are compatible with KLUMP & GERHARDT's (1987) suggestion that the i
ntensity independence of female preferences varies with the relative b
enefit females obtain from each preference.