Brown-headed cowbirds (Molothrus ater) are a robust species for studying female mating preferences. The auditory forebrain nuclei in both males and females show distinct selectivity for conspecific song. This pathway as a song-producing mechanism has been well-studied in males. What is less studied, however, is the female equivalent of this pathway. While it exists, not much research has shed light on how it relates to the sensorimotor pathway. While male cowbirds sing, female cowbirds go into mating posture (also known as copulation solicitation display, or CSD), similar to the mammalian lordosis.
This summer, I continued my project investigating what auditory features contribute to females going into CSD more often. For example, does taking out the flight whistle at the end of a male mating call elicit more postures from females? In addition to this question, I also addressed whether RA, a nucleus in the midbrain, plays an excitatory or inhibitory role in posture production. Recorded songs were played to RA-lesioned and sham-lesioned females in their respective sound attenuation chambers. The results showed that RA-lesioned birds went into posture more often, and that the robustness of their posture was higher compared to their sham-lesioned counterparts. It has not been confirmed yet, however, whether the RA lesion surgeries have successfully hit their target regions in the brain. In the future, we wish to identify more auditory features of male song that contribute to their potency, that is, how often they produce CSD from females.