WHY BIRDS SING: A JOURNEY INTO THE MYSTERY OF BIRD SONG.  David
Rothenberg.  New York: Basic Books, 2005

Some time ago we had a discussion about whether or not bird song could
be considered music, and I recall Steve Schwartz saying that this depends
on whether birds ever sing just for the hell of it.  Not quite a scientific
formulation of the question, but even the more straightforward wording
in the title of this fascinating book is enough to embarrass scientists,
who are more comfortable with asking "how" rather than "why" about
anything, and who would be hard-pressed actually to prove that even a
fellow human is feeling joy.  Rothenberg, who is both a philosophy
professor and a musician-a classically trained jazz clarinetist and
composer-is strongly inclined to say that bird song is music.  Some birds
actually make up their own songs.  His initial explanation of why male
birds sing-and it is the male which sings--is that female birds like it;
his final explanation is the same as his explanation of why people sing:
because they can.

In between the question and the answer are ten extremely well written
and informative chapters ranging from Rothenberg's personal attempts to
play music with birds, first in the National Aviary in Pittsburgh and
finally in an Australian rain forest (hear the results for yourself at
www.whybirdssing.com) to a chapter on composers' use of birdsong, from
Vivaldi to Messiaen (I had not known that the latter produced a seven-volume
treatise including 1200 pages of description of birds' songs), a strictly
scientific account of recent study of the brains of songbirds (in which
Rothenberg expresses ethical misgivings about cutting off birds' heads
after they have "sung their heads off"), and accounts of individual
researchers who wrote hundreds of pages about the songs of particular
birds.  He quotes poets at length and transcribes bird songs in traditional
musical notation, in sonograms and other schemes.

So what is known, or agreed on?  First, not all birds sing, and there
are wide differences among those which do.  Bird calls are distinct from
bird songs.  Calls have meaning and communicate facts such as the presence
of a hawk overhead (and several species have very similar simple cries
for this).  Songs have function but not specific meaning, chiefly in
courtship and in establishing territory.  These may be the exact same
songs, but typically the territorial songs are harsher and briefer and
the courtship songs may be vastly more elaborate and extended than one
would think functionally necessary.  Not only that, but the songs may
exhibit considerable variation within the songs-some birds actually
develop themes-- and may even vary from individual bird to individual
bird, notably in the case of Starlings.  It is the male birds that sing,
as I said, but injections of testosterone in a female will result in her
singing also.  (There is another striking instance of this in the final
chapter which I will not spoil by relating.) Birds sing through both
sides of their syrinx and can sing different notes on each side (a feat
comparable to a double reed player who could produce double stops!) Bird
songs are learned, note by note or phrase by phrase, frequently in
adulthood, not at the busy rearing stage, sometimes as a result of years
of practice, and not always from other birds of the same species.  Here
is where things get really interesting.

Rothenberg discusses several species noted for mimicry which have very
lengthy and varied songs.  The Mockingbird, for instance, can sing for
a half-hour without repetition; transcribed musically, this fills forty
pages.  If you consider that birds typically sing notes twice as fast
as humans can even hear them, this might be equivalent to an hour-long
composition.  A Mockingbird may have a repertoire of 200 basic phrases;
the Brown Thrasher has 2000.  As for inter-species song-making, one
unusual instance cited by Rothenberg is the (European) Marsh Warbler,
which combines song-elements from other European birds with some from
birds from East Africa, where it winters.  Another is a particular
(Australian) Lyre Bird which, kept as a pet by a flute-playing farmer
for a few years before being released to the wild, blended into its
repertoire two, and only two, popular songs from those the flutist had
repeatedly played; thirty years later other Lyre Birds were heard to
have incorporated flutelike imitations of the same songs in their extended
repertoires.

As for bird song being merely functional, that is hard to accept
when it can be shown that female birds-who do the actual choosing of
mates-sometimes make their selection on such criteria as the amount of
territory a male has rather than on the quality of the song.  Also, birds
sing far beyond the nesting season.  Male Marsh Warblers sing when "off
duty" and on sunny days get together in groups of 2-4 to sing together.

Jim Tobin