The Origins of Music: Preface - Preface

package is not necessarily identical,however,nor is the sequence as the

bird moves from one package to another.Every song is not sung each

time the bird cycles through its repertoire.Thus,in the example above,

song types A and C are omitted the second time round and will not occur

again until the next time that package crops up.In a bird with 200 types

it may be common for songs to show a recurrence interval of around 100

types,about half the songs being omitted during each passage through

the repertoire.

The songs of the nightingale may appear to be rather fixed in sequence,

falling into groups and the same ones often occurring close to each other,

but they are in fact highly varied.Once a song has been sung it is seldom

repeated for some time.If impressing potential mates is what it is all

about,a female nightingale would need a very good memory to recall

having heard a particular phrase before!

Sedge Warbler

The sedge warbler is a good example of a species in which elements can

be reassorted to make many different song types.Here successive songs

consist of different combinations of elements and elements are recom-

bined continuously,so that there is no fixed repertoire of types.Songs

produced in flight are even more complicated,but Catchpole (1976)

limited himself to describing the features of those sung by perched males.

Each bird has a repertoire of about fifty different element types.A

song is typically around one minute in length and consists of over 300

elements.It starts with a long section in which short series of two ele-

ments alternate with each other.There is then a sudden switch to a

louder,more rapid,and complex central section in which five to ten new

elements are introduced in quick succession.In the last part of the song

the patterning is similar to that at the start,except that the two elements

are selected from among those that occurred in the central section.These

same two elements are typically those that are employed at the start of

the next song.

Because it is long and has this varied patterning,the song of the sedge

warbler is extremely complex.Although it involves a relatively small

number of elements,“the probability of a song type ever being exactly

repeated seems remote”(Catchpole 1976).The sedge warbler thus

achieves variety in a different way than the nightingale:it has a limited

number of elements that it reassorts in particular ways to achieve an

apparently endless repertoire.

Starling

Starlings are well known for their long and complex songs,and for the

mimicry of other species that occurs within them.But,what at first may

55 Birdsong Repertoires

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