London, August 15 (ANI): Juvenile male crickets that do not hear a chorus when they are young grow into more aggressive adults, a new study by scientists from the University of California, Davis, US has found.
It suggests that the animals can pick up behavioural traits while young, which then become fixed in adulthood, the BBC reported.
For the study, the scientists captured juvenile field crickets that had not yet developed a tympanum, the equivalent to an ear, which grows on the cricket's front legs.
While one group of crickets were reared in silence, another were played a looped recording of five calling males.
"In the sound treatment there was a chorus of five different crickets playing back, calling, to mimic just what you would hear on a summer night, lots of different crickets calling and singing," said lead author Nicholas DiRienzo.
The silence was similar to the conditions experienced by juveniles hatching in spring when the cricket population tends to be at a low density, and hence quieter. Any juveniles born later tend to find a denser population of crickets, which is louder.
According to DiRienzo, the team's results suggested that juveniles use cricket song as an indicator for population numbers. This awareness appeared to make an impression on the young crickets, shaping their behaviour.
"The more that are calling, the more could be present in an environment. This backs a lot of other studies which show when you raise individuals actually in physical contact with higher density groups, they tend to be less aggressive," explained DiRienzo.
The study also discovered that the sound of calling affected the growth of the crickets.
Juvenile crickets, which were reared with the sound grew to be larger than all the other crickets in the study.
DiRienzo indicated that, if rearing conditions do have an effect on both growth and behaviour, this could have widespread consequences for our understanding of field cricket ecology.
The findings are published in the journal Animal Behaviour. (ANI)]