MALE TAIL LENGTH, SEXUAL DISPLAY INTENSITY AND FEMALE SEXUAL-RESPONSE IN A PARASITIC AFRICAN FINCH

Aviary experiments on the effect of tail length of males on the sexual response of females were carried out with a promiscuous, parasitic finch, the shaft-tailed whydah, Vidua regia. Oestradiol-treated females, presented with two males of widely differing tail lengths, performed copulation-solicitation displays to males with lengthened tails in preference to normal-tailed controls, and to controls in preference to males with shortened tails. Yet although males were always visually isolated from each other, individuals displayed and vocalized significantly more when their tails were longer than that of the other male, and less when their tails were shorter. Females presented with a long-tailed decoy and a short-tailed live male solicited neither, but spent significantly more time with the live male. © 1990.