|MadSci Network: Agricultural Sciences|
The chicken normally responds to light -- the trigger for egg laying is increasing light. Commercial we fool her by keeping a continuous even lighting. We also take away her eggs so she never has a "clutch" to set on. So she keeps trying. Also she is able to store sperm for a relatively long time. Thus, in the wild she would lay 6-10 eggs a year and quit. On a speculative plane -- I would assume that birds that flock together, so males are generally relatively abundant, might find this mechanism efficient.
Try the links in the MadSci Library for more information on Agricultural Sciences.