A note on the effect of changes in daylength on the seasonal wool growth cycle in Soay sheep

Abstract
SUMMARY: Seven Soay rams were subjected to a short daylength from the middle of August until the end of October, and this hastened the onset of winter follicle inactivity which normally begins at the end of September. A reversion to long days until the middle of January slowed down the process, and in six animals the usual spring moult was inhibited.