That’s
my song they’re singing is a critical realization in developing the personality
of young crickets. Young field crickets don’t have ears like you and me. They
develop a sort of equivalent on their front legs called a tympanum. We’re not talking about the
subtleties of medieval architecture but about a membrane, like that in our
middle ear, that vibrates in response to sound waves.
So
very young crickets can’t hear any singing in the hot evenings, but as they hit
adolescence they begin to develop their apparatus. DiRienzo et al in the latest J. Animal Behaviour
took up the challenge of personality development of field crickets brought up
with and without choral participation (1, 2).
Young
crickets were kidnapped and divided into groups. Some were brought up in
silence and some were brought up listening to taped numbers from a chorus of
five males singing in their prime.
Personality
questionnaires are out with crickets and so the only answer was to mix, match
and sit back to watch the entertainment. Those deprived of growing up in the
cacophony of song turned out to be more aggressive than crickets whose
tympanums had been vibrating to the nightly rhythms of cheeky, chirpy males.
The
idea used to explain this was that those who’d enjoyed the quiet life thought
that cricket density was low so a bit of aggression could do them some good. If
they had realized that cricket density was high, the aggression could get them
into lots of fights which would take up too much time and energy when they
could be devoting themselves to the numerous females that would also be around.
Taking an easy come, easy go approach would be the way to go.
However
another exciting side effect of chorality in the life of a maturing cricket was
that those that had lots of singing in their lives grew bigger. Perhaps if your
bigger, you don’t feel the need to pick fights by getting in the first blow. (See yesterday's post for example.)
Maybe
Congreve was a student of cricket when he penned his immortal line ‘Musick has
Charms to sooth a savage breast’ in The
Mourning Bride in 1697.
