Cardinal girls learn faster than boys

Science News, June 9, 2001 by S.M.

Female cardinals learn nearly as many songs as males but in only one-third the time, according to a new study that compared the results of his and her music lessons.

In most bird species in temperate climates, only the males sing. Among northern cardinals, however, both males and females become crooners. This unusual arrangement offers a great opportunity to explore gender differences, explains Ayako Yamaguchi, now at Yale University. Her earlier work documented subtle variations in the mature songs of male and female cardinals (SN: 8/29/98, p. 134).

To study differences in how the sexes learned those songs, Yamaguchi raised 26 youngsters in separate chambers. Over a year, each bird heard a sequence of recordings of at least 40 songs from adult cardinals.

Researchers knew that growing birds can pick up songs only during a set period. At the end of the year, Yamaguchi checked each bird's repertoire against the sequence of recorded songs. This indicated when the bird's receptive period had started and stopped.

Both males and females started learning songs about 3 weeks after hatching, Yamaguchi reports in the May 17 Nature. Although the females' sensitive period lasted about 49 days and the males' period extended to more than 187 days, the females generally had picked up four songs during that period and the males, five.

In the wild, this time difference could mean that males would keep learning even after they'd left their parents' nests to make homes of their own. Yamaguchi says this could enable them to pick up the song accents of their new neighborhoods and hold their own in the song-matching duels that enable males to define and defend their territories.