RIVERSIDE, Calif. In the animal kingdom, sexual signals often are manifested as displays of bright coloration or, in the case of crickets, as loud song.
Adult male crickets produce loud song to attract females, but the song, which permeates the environment, can be overheard also by unintended receivers - such as young males unable to produce song due to a mutation they carry.
Until now researchers have not understood how non-singing male crickets use the song of singing males to modify their behavior or physical attributes to their advantage.
Now biologists at the University of California, Riverside have shed light on this mystery.
In the lab, they exposed one set of juvenile male crickets to a silent environment (which mimicked a population without very many singing males) and a second set of young male crickets to a song-rich environment (mimicking a population that contained lots of singing males).
Comparing the two sets of data, they found that male crickets growing up in the presence of abundant male song tend to be larger than male crickets growing up in a silent environment, and invest nearly 10 percent more reproductive tissue mass in their testes.
The researchers also found that male crickets that do not hear song during rearing are more likely to act as 'satellites,' hanging out near singing males and intercepting females on their way for matings.
"Subtle modifications of behavior depending on the environment, not genes, means that even in insects, animals aren't 'programmed' or 'hard-wired' to do what they do," said Marlene Zuk, a professor of biology, whose lab conducted the research.
Study results appeared May 11 in the journal Current Biology.
"Larger is probably better for the crickets because it allows males to better c
|Contact: Iqbal Pittalwala|
University of California - Riverside