Fig. 3

Light levels (foot-candles) at the time of first exit and last return from or to the roosts across the season. a) Recordings made at first exit (r= -0.44, p<0.001, n=176) and b) at last return (r=-0.34, p<0.001, n=135) by visual counts at Løvhaug, all other roosts in Troms and at two roosts in Saltdal. c) Recordings made at the time of the first (r=-0.64, p<0.001, n=263) and d) last pass (r=-0.74, p<0.001, n=244) by IR detection at the three roosts Løvhaug, Bardu and Saltdal. The horizontal lightly dashed line represents 180 foot-candles, and the heavier dashed line is the regression line