Photoperiodic response of rain quail

The photoperiodic response of the migratory sexually dimorphic Rain quail were studied. Birds were subjected to constant long (18L : 6D) and constant short (6L : 18D) photoperiods. In addition birds receiving 6L : 18D treatment were given additional light pulse of an hour duration at 0,2, 4 & 6 hours after the end of 6 hour photophase. It is obvious that the photoinducible phase occurs after 12 hours of Sun rise or "Light on" phase. This is based on the fact that the testis remain small and inactive under short photoperiods and alson in birds receiving light pulse at 0,2 & 4 hours in which the photophase occured at 12 hour or earlier. The full development was observed in groups of birds in which only when the light was available at 13 hour. It also seems that the light inducible phase in this species probably like in weaver bird but similar to in temperate zone birds may be quite long. The results it is suggested confirm the concept of Bunning's hypothesis.