Female northern cardinals learn songs in one-third the time it takes male birds to learn the same number of songs, according to research at the University of California, Davis, by Ayako Yamaguchi, a former graduate student.
"It's the largest learning difference between sexes ever found," said Yamaguchi. Small sex-based differences in learning have been found in other animals, but these are usually so small that they are overwhelmed by individual variation.
Northern cardinals are unusual among temperate-zone birds because both males and females sing. In earlier work, Yamaguchi has shown that the birds can tell the difference between male and female songs. Birds learned songs by copying birds of either sex, but added sex-specific characteristics to them.
Young birds memorize songs during a time window called the sensitive period, and later practice their songs compared to the memory. Yamaguchi found that while the sensitive period started at around the same age for both sexes, it lasted more than three times as long in males as in females.
The ability to learn songs or language is very rare, having evolved only three times -- in birds, whales and humans -- said emeritus professor Peter Marler, who heads the Animal Communication Laboratory at UC Davis. Yamaguchi's research has opened up the whole area of gender-specific song learning, he said.