Fig. 4

Effects of nestbox availability on daily light exposure in C57BL/6J and Cry1^−/−Cry2^−/− animals. Daily light exposure (hrs) perceived by C57BL/6J (blue) and Cry1^−/−Cry2^−/− animals (orange) under different conditions. The combined nestbox and forage mix condition is referred to as ‘ + forage mix’. All results reported as mean across mice and days, ± SEM. **** p < 0.001, ** p < 0.01, * p < 0.05, between condition comparisons