Fig. 2

Impact of a photosensitive collar on the daily mass change of captive and wild lemmings. A, B The masses of six captive lemmings were monitored across 58 days in Cambridge Bay, NU, Canada. Period 1 and 2 are periods when lemmings are not equipped with a 1.5 g dummy collar, contrary to the Equipped period. In each period, daily mass gain was calculated. A Body mass of 4 captive brown (full lines) and 2 collared (dotted lines) lemmings. Rectangles delimit different periods. Symbols represent different individuals. B Daily mass changes of captive lemmings with 95% CI. The white triangle represents the weighted mean in each period, and squares and circles represent, respectively, brown and collared lemmings. Point size is proportional to the number of days the daily mass change is based on. C Field observations of daily mass changes of equipped and unequipped brown lemmings with their 95% CI in the Bylot Island, NU, Canada. White triangles are the weighted mean. Point size is proportional to the number of days the daily mass change is based on, here the time between captures)