why birds sing

I just finished watching the documentary Why Birds Sing on BBC4. David Rothenberg says they sing because they enjoy it (and a neurologist has contributed significant evidence to this theory by showing an increase in dopamine - a pleasure hormone - levels in birds' brains when they sing). Conventional bird-song science says that they sing to attract females to mate with, and that the females are attracted by the complexity of the song, and that there's no aesthetic sense in birds. But if that is the case, why are the female birds attracted to the song? If they find complex songs more attractive, then they're making an aesthetic judgment. QED. I don't understand why rationalists are so antipathetic to the idea that animals feel emotion. If there are gay animals (clearly having sex for a reason other than procreation, like emotional bonding) and animals that love to interact with other animals - like dogs and cats that like to hang out together - then clearly animals experience emotions. In The Science of Discworld, Jack Cohen mentions that he once had a praying mantis (an insect, for goodness' sake) that liked to do tricks to impress an audience, and would not perform if you gave him a trick that he considered too simple. So I can't see what is so irrational about saying that birds have an aesthetic sense, and sing for the sheer pleasure of singing. I don't think this is anthropomorphising birds. It is quite probable that early humans were inspired to make music by listening to birds, and this is why our musical scales are similar to theirs. It seems that rationalists want to take away any notion of love or spirituality, and explain everything mechanistically. I don't think it is irrational to say that birds and animals can experience pleasure (why else do cats enjoy stroking and food, bonobos enjoy sex, or humans enjoy all the things that we enjoy - after all, we are animals too).

There's also a longer article by David Rothenberg on why this is important.

"As human music grows to encompass ever more kinds of sounds and listens more sensitively to what is around us, there will be more interspecies music than ever before. It works best when the human musician welcomes the encounter with openness and respect, ready to take in the unfamiliar and genuinely learn something new, to change one's musical sense in the presence of new and exciting sounds. Approach the situation without too many expectations, and let us make music together that neither species could make apart. It is one more way for us to learn about and to appreciate the animal world."

And here's another article, featuring marvellous musical mice (who sing in octaves and shifts in the ultrasonic range).

Timothy Holy and Zhongsheng Guo of Washington University in St. Louis show that male mice “sing” to females in ultrasonic ranges.

“Individual males produce songs with characteristic syllabic and temporal structure,” the authors write.

In this study of captive animals, the mice sing primarily in octaves and shifts. In a study of wild California wild mice, other researchers found that the mice sang in thirds. Patricia Gray says, “This is phenomenal to me as a musician that intervals do matter. They matter to us and to other species as well.”