Mc. Baker, DOES EXPOSURE TO HETEROSPECIFIC MALES AFFECT SEXUAL PREFERENCES OF FEMALE BUNTINGS (PASSERINA), Animal behaviour, 48(6), 1994, pp. 1349-1355
Indigo buntings, Passerina cyanea, and lazuli buntings, P. amoena, for
m hybrid pairs during the breeding season, although the frequency of h
ybrid pairs is less than expected if mating is at random. The antecede
nt conditions leading to hybrid pairing are unknown. In the experiment
reported here, adult female indigo and lazuli buntings from allopatri
c populations were photostimulated and implanted-with oestradiol to at
tain reproductive condition in the presence of heterospecific males. F
emales were exposed for 25 days to vocal and visual displays of hetero
specific males while developing reproductive physiology and behaviour.
Females were then tested for their preferences, as indicated by copul
ation solicitation displays, for conspecific versus heterospecific mal
es and their vocalizations. Additionally, songs of several males were
recorded before and after exposure to females and subsequently examine
d for structural modifications that may have been caused by the exposu
re to heterospecific females. Females of both species preferred conspe
cific males and their vocalizations in tests following the heterospeci
fic exposure treatments. Comparisons with previous experiments on fema
le buntings suggested that the 25-day stimulation from heterospecific
males was unable to alter female preference for conspecific males. Nor
were male songs structurally altered as a consequence of exposure to
heterospecific females.