Fig. 2

a Sample actogram showing the data taken from one Red-wattled lapwing chick. The orange line represents the activity of the chick expressed as ODBA, the blue dashed line represents the ambient temperature, the red line the on-body temperature measured by the datalogger on the chick’s dorsal part, the black line the light-level, and the yellow line the sun elevation. The green polygons below represents predicted brooding. b–d are zoomed parts of original actogram highlighted by black frames. b shows the typical brooding bout during the daylight—see the low activity level, together with the increasing on-body temperature and close to zero light-level. c shows the typical brooding bout during the night—see the low activity level, together with the increasing on-body temperature; light-level is during the night constantly close to zero. d shows the typical pattern connected to the stay in the shade. Although there is visible temperature drop from very high temperatures (i.e. much above the birds body temperature), this is not associated with the drop in the activity level. Moreover, light-level is much higher than expected during the brooding and is in the range typical for stay in the shade of plants