It’s spring and Northern Cardinals are really making their presence known all over the place. When I was running through Freedom Park (and when I was walking across campus and when I was on my way home and…), I looked up to see a cardinal singing, but instead of being the bright red male, it was the female doing the performance. It was no Lady Gaga number; after all, they’re cardinals and not mockingbirds. Even so, these females were belting out a nice, simple, recognizable cardinal type song.
In songbirds, song has been studied a lot and people have realized that a typical male song has two functions, generally. The first is to advertise his presence and help him claim or maintain a territory from other males. The second function of song is in mate attraction. Females often use aspects of the song performance in evaluating a potential mate. Hmm…I was coming up with sarcastic things to say about band groupies, but I’ll let that slide for now.
Given how song is used in the males, what are female cardinals getting out of it. Actually, there have been several studies that have tried to address this question and they’ve approached the problem by showing what females are NOT doing with their songs.
1. They don’t seem to use them to establish territories. The frequency of singing by females does not increase with territorial intrusions by other birds of either sex.
2. They don’t sing after a mate has been removed, so singing is not for mate attraction.
Ok, so neither of the functions of song present in males seem to apply to female song in cardinals. Well, apparently, females tend to sing after acquiring a mate, but before settling down in the nest with eggs. The current hypothesis that seems to be able to explain singing behavior in females seems to be that female song may function in the development of the pair bond (and in getting ready to mate). The fact that female song often accompanies male song (a duet) just adds support to this kind of interpretation. Singing together just may be that little bonding behavior that gets them out of the woods and into the nest. I can just hear them now, “Love…love will keep us together…” Well, at least for this breeding season.