MOLTING CYCLES IN EUROPEAN QUAIL (COTURNIX-COTURNIX COTURNIX) UNDER CONSTANT PHOTOPERIODIC CONDITIONS

Male and female European quails (Coturnix coturnix coturnix) were stud ied whilst being maintained in LD 12: 12, at 20 degrees C, for four ye ars from birth. The birds exhibited the following phases: end of the f irst phase of the post-juvenile moult, fattening and a period of noctu rnal activity. Then sexual development is observed up to complete matu ration at the age of four months. The second part of post juvenile mou lting occurs towards the age of 5 to 6 months. During the following 6 months an important phase of reproduction is observed, thus completing their first year of life. The same sequence is repeated during the fo llowing years: a moult which lasts for 6 months in two (sometimes thre e) partial phases separated by episodes of reproduction; then an impor tant period of reproduction (6 months) without moulting. The birds are capable of reproducing at all times except during moulting. The seque nce of moulting begins each year in the same months as those for natur al French populations. IL thus seems that the annual periodicity and t he organisation itself of the phenomenon of moulting is controlled in European quail by an endogenous circannual rhythm. In contrast, the na tural cyclic expression of sexuality appears to be dependent on abioti c environmental and social factors.