In cordon bleus, song develops independently of sex differences in the brain

In female songbirds, brain areas responsible for song learning are usually smaller and have fewer neurons compared to males. However, in many species such as the blue-capped cordon bleu, females possess an elaborate song. Scientists from the Max Planck Institute for Ornithology in Seewiesen now found in this species pronounced sex differences in the brain already in juvenile birds, where females had up to 50% less neurons in the song control areas. However, this had no effect on the song learnin