The learning powers of nightingales surpass those of people in some
ways, say zoologists in Germany. Young birds have a highly developed ability
to learn complex melodies from their elders in the wild or from tapes in
the laboratory.
Dietmar Todt and Henrike Hultsch at the Free University of Berlin isolated
captive nightingales (Luscinia megarhynchos) at birth, then 鈥榯utored鈥� them
by playing tapes of birdsong. They found that nightingales can often repeat
complicated new strings of up to 60 phrases after hearing them once a day
for between two and three weeks.
The nightingale is a good subject for study, says Todt, because it has
a huge musical repertoire, built from 900 or so melodic elements. 鈥楨xperiments
can be carried out which would not be possible with birds with just a few
song types,鈥� he says. The nightingale also has a clear and precise voice.
鈥楾hat makes it easy for us to identify imitations which the bird learns
from tapes,鈥� says Todt.
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The nightingales achieve their remarkable feats of learning by combining
short-term memory with 鈥榮ubmemories鈥� which operate in parallel, say the
two zoologists. The processing of information involves breaking it down
into chunks, says Todt. 鈥楾he nightingale can store seven songs 鈥� each of
around 50 seconds 鈥� in its short-term memory.鈥�
The birds subdivide the 鈥榮ongs鈥� into smaller packages of 鈥榓coustic鈥�
memory, each of which contains around three to four phrases. To recall a
song, the nightingale reassembles the required phrases from its acoustic
memory.
Todt and Hultsch believe their work will help in understanding the biological
mechanisms in human memory.
