Fig. 2
From: Using skin temperature and activity profiles to assign chronotype in birds
Diel profiles for skin temperature (A) and activity (B) for each individual Great Tit (unsmoothed data in different colours) and mean (black solid curves) ± standard error (black dashed curves) for the full data set. Blue curve shows the fitted sinusoidal curve (with 3 harmonics) for skin temperature. Horizontal red lines show overall mean (levels). Daylight phases are indicated in yellow (sunrise–sunset)